16
lFL(())W SIZING lJBrlB V AlL VlBS D-Zero Engineering Note: 3740.51 0-EN-20 1 C.H. Kurita January 19, 1989 Reviewed: -- --
lFL(())W SIZING lJBrlB
C~Y(Q)SYSllBM V AlL VlBS
D-Zero Engineering Note 374051 0-EN-20 1
CH Kurita
January 19 1989
Reviewed -- -~--7F-~---------------
-- ---~------------
I
~FL~O~W~S~I~Z~IN~G~C~RY~Q~S~Y~SuT~E~M~V~A~L~Y~E~S_______________________2
-FLOW SIZING
CRYOSYSTEM VAL VES
INTRODUCTION
The liquid argon dewar and the three cryostats which contain the modules of the D-Zero detector are cooled and maintained at a low pressure equilibrium by the use of liquid nitrogen cooling loops The dewar has one vacuum jacketed valve at the inlet of the cooling loop and one at the outlet Each cryostat has two inlet valves one for the cooldown loops and one for the operating loops in addition to an outlet valve
The flow rate of the liquid nitrogen and hence the valve sizes and corresponding flow coefficients (Cv) is deter mined by the required cooling rate of each system The large variance between the cooling rate required - for cooldown and that required for operation and the high control resolution required makes the selection of a valve seat and plug difficult The liquid valve coefficient calculations do not specifically consider the size affect of gas generated within the valve by adiabatic pressure drop See Appendix I for a calculation of the magnitude of this effect
The figures and a graphical and tabular summary of the papers conclusions are presented in Appendix II
LIQUID ARGQN DEWAR CONDENSER
Liquid Argon Condenser Mass Flow Rate
The liquid argon storage tank specified condenser capacity of is 60 kW at 5 psig argon and 80 K nitrogen We will use 40 kW as the maximum cooling rate required The required maximum mass flow rate is then 205 gls (406 gpm) When operating in a quiescent state the necessary minimum cooling rate is 03day or 410 W The minimum mass flow is 21 gls (004 gpm)
2
~FL~O~W~SuI~ZI~N~G~C~R~Y~O~S~Y~ST~E~M~V~A~L~Y~E~S~_____________________3
- Liquid Argon Condenser Inlet Valve
The pressure drop across the inlet valve is expected to range from a minimum value of 13 atm (195 psid) to a maximum value of 29 atm (435 psid) Minimum and maximum flow coefficients were calculated from these values using the following formula for liquid flow from CVIs Cryogenic Standard Products
Cv - QI(GIAP)O5 (I)
where Cv = Valve Flow Coefficient 6P = Pressure Drop (psi) Ql = Liquid Flow Rate (gpm)
density of subject fluid G = Specific Gravity= density of water
For the maximum cooling rate of 40 kW Cv LP=054 and the Cv HP=08 However when the cooling rate is only 410 W the flow coefficients are significantly smaller with Cv LP=0005 and CV HP=0008 This wide range of desired flow coefficients (100 1 ) necessitates the use of a plug capable of covering a broad spectrum A possible solution is an
J eq ual percentage plug 1 for the full range and 12 stroke valve operation when the operation requires the smaller Cvs for low flow resolution
The installed valve has a flow coefficient of 34 It is necessary to install a new seat and plug that has a Cv 1
Liquid Argon Condenser Outlet Valve
The mass flow rates through the outlet valve are taken to be the same as those used for the inlet valve calculations The associated flow rates are a minimum of 2064 scfh and a maximum of 20950 scfh
The valve vents to atmosphere and again allowing for a range in the pressure of the nitrogen in the cooling loops the pressure drop across the outlet valve can vary from 04 atm (6 psid) to 1 atm (15 psid) These values were used to calculate minimum and maximum flow coefficients
1 CVI Cryogenic Standard Products The Percentage Valve Plug is designed to vary the fluid flow in an equal percentage ratio with each increment of valve lift The Percentage Plug is used in cases where the operating conditions are definitely established before installation or where it is desirable to use a valve larger than
-- would ordinarily be necessary
3
LFL~Q~W~S~I~Z~IN~G~CR~Y~Q~S~Y~SuT~EpoundM~V~A~LuV~E~S_______________________4
using the formula for gaseous flow from CVIs Standard Cryogenic- Products
Cv =(Qg 1391 HTGI APP2o5 (I I)
where Cv == Valve Flow Coefficient 6P = Pressure Drop (p sid) Qg = Gaseous Flow Rate (scfh)
density of subject gas at STP G == Specific Gravity= density of air at STP
T = Absolute Temperature COR) P2 = Downstream pressure (psia)
For the maximum cooling rate of 40 kW CV LP=105 and Cv HP=167 The minimum cooling rate of 410 W results in CV LP=010 and Cv HP=016 The valve mounted in the line has a Cv=34 suitable for the larger Cv calculated However because of the large range between the maximum condenser and quiescent states (1001) the Cv should be changed to 16 and an equal percentage plug with a limited stroke for small Cv values
-- should be used
4
LFL~O~W~SuI~ZliIN~GLkCR~Y~O~SuY~S~T~E~MLLV~A~L~V~E~S_______________________5
- CRYOSTATS
Cryostat Mass Flow Rate
The mass flow rate of nitrogen in the cryostat cooling loops is determined by the required cryostat cooling rate For the cooldown loops the required cooling rate can range from 10 kW to 40 kW With the typical pressure in the loops at 3 atm the range of mass flow is from 55 gls (108 gpm) to 218 gls (433 gpm) The operating loops have a required cooling rate that varies from 1 kW to 10 kW depending upon whether operating or cooldown conditions are being experienced The mass flow rate for the operating loops ranges from 546 gls (0108 gpm) to 546 gls (108 gpm)
Cryostat Line Pressure Drop
In transport from the nitrogen dewar to the cryostats a change in pressure occurs due to the change in elevation and the flow of fluid through a pipe The pressure increase brought about by the change in elevation is 0342 psilft For the 1975 ft elevation difference the increase in pressure head of the liquid is 6754 psi The length of piping to the north end calorimeter (NEC) is used to calculate the pressure drop due to the flow of fluid through a pipe because it has the longest length and thus the largest pressure drop Using 1-12 pipe the length of straight pipe from the nitrogen dewar to the NEC inlet valve is 33703 ft Taking into account the flow through the straight pipe one 45 0 elbow twenty-three 90deg elbows two tees 5 bayonets and two I angle valves the equivalent length of straight pipe becomes 48703 ft The pressure drop due to liquid flow through a pipe at 185e-5 psilft is 90 le-3 psi small in comparison to the pressure increase (subcooling) from the 6745 psi liquid head See Cryostat Liq uid Quality for discussion of the 10 OW line loss generated 05gs gas flow
Cryostat VJ Line Heat Leak
The heat leak experienced in transport through the pipe valves and bayonets is calculated to be 100 W The increase in pressure from the head of the liquid provides a subcooling proportional to the flow rate The heat leak into the system just balances the subcooling if the flow is 37 gs
5
--------~---~--------
r-shy
)
~FL=Q~W~S~I~ZI~N~G~C_R~Y~O=S~Y~ST~E~M~V~A~L~V~E~S~_____________________6
For example a flow of 546 gls produces 149 W of subcoolingwhkh results in a net value of 49 W of the subcooling of the liquid
Cryostat Liquid Quality
Saturated liquid flowing into the cryostat inlet valve experiences a pressure drop of I atm the quality of the liquid entering the cooling loops is 962 (98 for 05 atm) To insure saturated liquid is flowing into the inlet valve after being transported along the piping (I OOW heat loss) from the nitrogen dewar a self-contained gaseous nitrogen vent valve (CVI) can be mounted in the line close to the cryostats to vent any gas present in the line Alternatively a subcooling control valve can be arranged in such a way that it provides a one atmosphere saturated flow through a small line coxial with the cryostat supply manifold and vents to atmosphere Either method would provide the inlet valves with high quality liquid and the latter with a controlled level of subcooling See fig 2
Cryostat Cooldown Loop Inlet Valve
If the dewar pressure is set to 55 psia and a pressure drop of 10 psi is experienced when the liq uid nitrogen passes through the valve the range of flow coefficients calculated range of mass flow rates from 10 kW to 40kW Using formula (I) to calculate the flow coefficients Cvmin=03 and Cvmax= 122 Since the flow coefficient bounds differ only by a factor of four a linear plug 2 with a Cv = 15 would be appropriate for this application
Cryostat Operating Loop Inlet Valve
If the pressure drop across the operating inlet valve is the same as that across the cooldown inlet valve (10 psi) values for the flow coefficient can be calculated for the valve when it is both experiencing operating (nominal flow) and cooldown (maximum flow) conditions Again using formula (I) it is found that CVmin=003 and Cvmax=03 (101) A linear plug with a Cv=05 could be used in this application with the valve limited to 112 stroke for improved resolution in operating mode
2 CVI Cryogenic Standard products The Linear Valve Plug is designed to vary the fluid flow in direct proportion to the valve lift throughout the range It is generally recognized as providing the most satisfactory control characteristic for the majority of applications Particularly suitable for high flow rates
6
--~-~ --------shy-
~FL~O~W~S~I~ZI~N~G~C~R~Y~O=S~Y~ST~E~M~V~A~L~V~E~S~_____________________7
Cryostat Loop Outlet Valve
The outlet valve vents the gaseous nitrogen to atmosphere and has a pressure drop of 30 psi It must be able to accommodate a flow range from the nominal value of the operating loops 546 gls (5573 scfh) to the maximum value of the cooldown loops 2184 gls (22292 scfh) By using form ula (IO the range of flow coefficients can be calculated It is found that CVm in=020 and Cvmax=80 (40 1) and the equal percentage plug 12 stroke solution will be applied
Cryostat Gas MakeupReturn Valve The cryostats and the LAr source dewar gas spaces communicate
through a valve that supplies makeup gas to the cryostat on cooldown and condensing and returns gas to the dewar on warmup or above some set pressure during normal operation
The expected makeup and return pressure differences are taken as 5psid the maximum flow the condenser flow to the cryostats is 250 gIs and the minimum flow return under nominal conditions is 625 gs The calculated Cvmax =255 and the Cvm in=064 (401) will require the equal percentage and 112 stroke option
) CONCLUSION
The small Cv values calculated and the large turndown ratios of the valves make the valve and plug selection process difficult The large range of necessary Cv values can be accomplished however by using equal percentage plugs Limiting the stroke of the valves to 50 by controlling the drive signals to 4-12ma (rather than 4-20ma) will allow for closer control of the very low operating flows through increased loop gain This combination of techniques should adequately cover the requirements as described
7
DFL~O~W~SuI~ZI~N~G~C~R~Y~O~S~Y~ST~EwM~VuA~L~VLE~S~_____________________8
--
Appendix I
Control valye Liauid Quality
The inlet liquid enthalpy is related to exit liquid and gas enthalpyies as
where HoPo the inlet sat liquid enthalpy HI P I = the exit liquid enthalpy HgPl = the exit vapor enthalpy
Q = liquid quality = (I-x) x vapor fraction
For the Operating loop-inlet Po 35 atm PI 30 atm
J x = (-95175 98938)(98938 + 84169) 002
see enthalpy vs pressure curve figure 1
The corresponding Cy 1) is only 14 of the that calculated in this report 2) affects only the upper flow limit 3) and will be considered by selecting Cy values 10 to 20 larger than calculated for liquid flow This general conclusion applies to all the applications considered here
Note too that subcooling by 05 atm or more prevents the formation of vapor in this case A gt1 atm subcooler will be considered for the critical cryostat feed manifold application see figure 2
8
LFL~OpoundW~SulkZIuNllG~C~R~Y~O~S~Y~STLE~M~VuA~L~VLE~S~_____________________9
Appendix II
Figures
1 Saturated LN2 Enthalpy 2 Liquid Quality Control
Supporting Graphs and Tabulations
1 Approximate Cv as a function of nominal valve size
2a Valve responses for i quick opening 11 linear ill equal percentage (log)
- titi half stroke equal percentage
J 2b Log plot of
1 2a iii 11 2a iiii
3 Valve sizing Liquid Argon Dewar
4 Valve sizing Cryostat cooling Loops
5 Valve sizing Cryostat gas makeupreturn
9
Saturated LN2 Enthalpy
-80
-90
t)J) 01 -100 - ~
=shy-CS- =
j ~ -110
-120
~ V
V V
~V j V
lI J
V
I
-130
o 1 2 3 4 5 6
Pressure Atm
-~ F-l
)
The sum of the heat leaks to the supply manifold is 1OOW The sub-cooling provided by the source and cooling loop elevation differences is just equal to 100W at a manifold flow of 37 gls Above that flow the liquid quality is 100 GN2 venting or suplimentary subcoolshying is required for smaller flows The calculated steady state manifold flow requirement is 165 gIs requiring a ventlsubcooling flow of 0275 gls (0005gpm)
)
F-2
CV data 5
4
3
2
o 00
I
I
I
~
V~
01 02 03 04 05 06
Diameter in
J
CV data 35
30
25
~ 20Q =rJl 15
U 10
5
0
J
I J
)
~
V ~
lshy00 02 04 06 08 10 12 14 16
I
Diameter in A2-1
-------~--
Valve Responses 100
80
~
= 600 til
-=-0
40 ~ gt= 20
o
I ~ o--7 ~ - V
J 1111 IL
I ~ v V
I ~ lV
~ III ~
V
I l
V II
1 1V
~ V
lV
1 ~V J
o 10 20 30 40 50 60 70 80 90 100
Flow
) A2-2a
Equal Pct (log) Plug
100
90
80
~ 70
= 600til 50 0
=- 40
~ 30-gt= 20
10
I
V J
1
V ~ ~
Vmiddot
l
II
I II
r
I
1
101
Flow
viol
I r
i
--
lL(Q)Sldisect9 VSllive Sizmg
ARGON DEWAR LN2 CONDENSER
LOADS
INLET Nom Range LN2(gs)
(gpm) Cv
)
OUTLET Nom Range GN2(gs)
(sctb) Cv
Notes
Max Min 40kW
100(14) 205 6 054 08
100(14) 205 209k 105 167
410W
1 21 004 0005 0008
1 21 206 010 016
1 Equal percentage (log) plugs
)
Remarks Condensing Steady State
full(hali) stkl
10 LN2 press hi LN2 press
full(half) stkl
10 LN2 press hi LN2 press
~-3
CRYOSTAT COOLING LOOPS
LOADS
CD INLET Range LN2(gs)
(gpm) Cv
OPINLET-) Range
LN2(gs) (gpm)
Cv
OUTLET Range LN2(gs)
(scfh) Cv
Notes
Max
40kW 4 218 433 122
10kW 10(5) 55 108 03
40kW 40(6) 218 22k 80
Min Remarks
10kW 1 linear plug 55 108 03 hi LN2 Press
1kW 1 full(half) stkl 55 011 003 10 LN2 press
1kW 1 full (halt) stkl 55 557 02
~ 1 Equal percentage (log) plugs
)
-~
A2-4
I middot bull
tA JL(Q)adisect9 Valive sectflzllimg
CRYOSTAT GAS MAKEUPIRETURN 1
LOADS Max Min Remarks
asINLET3 40kW 1kW Range 40(6) 1 full(halt) stk2
LAr(gs) 250 625 (scth) 195k 049k
Cv 255 064
--asOUTLET3 5kW 1kW Range 5 1
) LAr(gs) 313 625 (scth) 24k 049k
Cv 32 064
-~
Notes 1a Makeup(cooldown) = Reverse acting b Retum( operate) = Direct acting
2 Equal percentage (log) plugs 3 This is one valve take more severe Inlet service requirements
)
A2-S
I
~FL~O~W~S~I~Z~IN~G~C~RY~Q~S~Y~SuT~E~M~V~A~L~Y~E~S_______________________2
-FLOW SIZING
CRYOSYSTEM VAL VES
INTRODUCTION
The liquid argon dewar and the three cryostats which contain the modules of the D-Zero detector are cooled and maintained at a low pressure equilibrium by the use of liquid nitrogen cooling loops The dewar has one vacuum jacketed valve at the inlet of the cooling loop and one at the outlet Each cryostat has two inlet valves one for the cooldown loops and one for the operating loops in addition to an outlet valve
The flow rate of the liquid nitrogen and hence the valve sizes and corresponding flow coefficients (Cv) is deter mined by the required cooling rate of each system The large variance between the cooling rate required - for cooldown and that required for operation and the high control resolution required makes the selection of a valve seat and plug difficult The liquid valve coefficient calculations do not specifically consider the size affect of gas generated within the valve by adiabatic pressure drop See Appendix I for a calculation of the magnitude of this effect
The figures and a graphical and tabular summary of the papers conclusions are presented in Appendix II
LIQUID ARGQN DEWAR CONDENSER
Liquid Argon Condenser Mass Flow Rate
The liquid argon storage tank specified condenser capacity of is 60 kW at 5 psig argon and 80 K nitrogen We will use 40 kW as the maximum cooling rate required The required maximum mass flow rate is then 205 gls (406 gpm) When operating in a quiescent state the necessary minimum cooling rate is 03day or 410 W The minimum mass flow is 21 gls (004 gpm)
2
~FL~O~W~SuI~ZI~N~G~C~R~Y~O~S~Y~ST~E~M~V~A~L~Y~E~S~_____________________3
- Liquid Argon Condenser Inlet Valve
The pressure drop across the inlet valve is expected to range from a minimum value of 13 atm (195 psid) to a maximum value of 29 atm (435 psid) Minimum and maximum flow coefficients were calculated from these values using the following formula for liquid flow from CVIs Cryogenic Standard Products
Cv - QI(GIAP)O5 (I)
where Cv = Valve Flow Coefficient 6P = Pressure Drop (psi) Ql = Liquid Flow Rate (gpm)
density of subject fluid G = Specific Gravity= density of water
For the maximum cooling rate of 40 kW Cv LP=054 and the Cv HP=08 However when the cooling rate is only 410 W the flow coefficients are significantly smaller with Cv LP=0005 and CV HP=0008 This wide range of desired flow coefficients (100 1 ) necessitates the use of a plug capable of covering a broad spectrum A possible solution is an
J eq ual percentage plug 1 for the full range and 12 stroke valve operation when the operation requires the smaller Cvs for low flow resolution
The installed valve has a flow coefficient of 34 It is necessary to install a new seat and plug that has a Cv 1
Liquid Argon Condenser Outlet Valve
The mass flow rates through the outlet valve are taken to be the same as those used for the inlet valve calculations The associated flow rates are a minimum of 2064 scfh and a maximum of 20950 scfh
The valve vents to atmosphere and again allowing for a range in the pressure of the nitrogen in the cooling loops the pressure drop across the outlet valve can vary from 04 atm (6 psid) to 1 atm (15 psid) These values were used to calculate minimum and maximum flow coefficients
1 CVI Cryogenic Standard Products The Percentage Valve Plug is designed to vary the fluid flow in an equal percentage ratio with each increment of valve lift The Percentage Plug is used in cases where the operating conditions are definitely established before installation or where it is desirable to use a valve larger than
-- would ordinarily be necessary
3
LFL~Q~W~S~I~Z~IN~G~CR~Y~Q~S~Y~SuT~EpoundM~V~A~LuV~E~S_______________________4
using the formula for gaseous flow from CVIs Standard Cryogenic- Products
Cv =(Qg 1391 HTGI APP2o5 (I I)
where Cv == Valve Flow Coefficient 6P = Pressure Drop (p sid) Qg = Gaseous Flow Rate (scfh)
density of subject gas at STP G == Specific Gravity= density of air at STP
T = Absolute Temperature COR) P2 = Downstream pressure (psia)
For the maximum cooling rate of 40 kW CV LP=105 and Cv HP=167 The minimum cooling rate of 410 W results in CV LP=010 and Cv HP=016 The valve mounted in the line has a Cv=34 suitable for the larger Cv calculated However because of the large range between the maximum condenser and quiescent states (1001) the Cv should be changed to 16 and an equal percentage plug with a limited stroke for small Cv values
-- should be used
4
LFL~O~W~SuI~ZliIN~GLkCR~Y~O~SuY~S~T~E~MLLV~A~L~V~E~S_______________________5
- CRYOSTATS
Cryostat Mass Flow Rate
The mass flow rate of nitrogen in the cryostat cooling loops is determined by the required cryostat cooling rate For the cooldown loops the required cooling rate can range from 10 kW to 40 kW With the typical pressure in the loops at 3 atm the range of mass flow is from 55 gls (108 gpm) to 218 gls (433 gpm) The operating loops have a required cooling rate that varies from 1 kW to 10 kW depending upon whether operating or cooldown conditions are being experienced The mass flow rate for the operating loops ranges from 546 gls (0108 gpm) to 546 gls (108 gpm)
Cryostat Line Pressure Drop
In transport from the nitrogen dewar to the cryostats a change in pressure occurs due to the change in elevation and the flow of fluid through a pipe The pressure increase brought about by the change in elevation is 0342 psilft For the 1975 ft elevation difference the increase in pressure head of the liquid is 6754 psi The length of piping to the north end calorimeter (NEC) is used to calculate the pressure drop due to the flow of fluid through a pipe because it has the longest length and thus the largest pressure drop Using 1-12 pipe the length of straight pipe from the nitrogen dewar to the NEC inlet valve is 33703 ft Taking into account the flow through the straight pipe one 45 0 elbow twenty-three 90deg elbows two tees 5 bayonets and two I angle valves the equivalent length of straight pipe becomes 48703 ft The pressure drop due to liquid flow through a pipe at 185e-5 psilft is 90 le-3 psi small in comparison to the pressure increase (subcooling) from the 6745 psi liquid head See Cryostat Liq uid Quality for discussion of the 10 OW line loss generated 05gs gas flow
Cryostat VJ Line Heat Leak
The heat leak experienced in transport through the pipe valves and bayonets is calculated to be 100 W The increase in pressure from the head of the liquid provides a subcooling proportional to the flow rate The heat leak into the system just balances the subcooling if the flow is 37 gs
5
--------~---~--------
r-shy
)
~FL=Q~W~S~I~ZI~N~G~C_R~Y~O=S~Y~ST~E~M~V~A~L~V~E~S~_____________________6
For example a flow of 546 gls produces 149 W of subcoolingwhkh results in a net value of 49 W of the subcooling of the liquid
Cryostat Liquid Quality
Saturated liquid flowing into the cryostat inlet valve experiences a pressure drop of I atm the quality of the liquid entering the cooling loops is 962 (98 for 05 atm) To insure saturated liquid is flowing into the inlet valve after being transported along the piping (I OOW heat loss) from the nitrogen dewar a self-contained gaseous nitrogen vent valve (CVI) can be mounted in the line close to the cryostats to vent any gas present in the line Alternatively a subcooling control valve can be arranged in such a way that it provides a one atmosphere saturated flow through a small line coxial with the cryostat supply manifold and vents to atmosphere Either method would provide the inlet valves with high quality liquid and the latter with a controlled level of subcooling See fig 2
Cryostat Cooldown Loop Inlet Valve
If the dewar pressure is set to 55 psia and a pressure drop of 10 psi is experienced when the liq uid nitrogen passes through the valve the range of flow coefficients calculated range of mass flow rates from 10 kW to 40kW Using formula (I) to calculate the flow coefficients Cvmin=03 and Cvmax= 122 Since the flow coefficient bounds differ only by a factor of four a linear plug 2 with a Cv = 15 would be appropriate for this application
Cryostat Operating Loop Inlet Valve
If the pressure drop across the operating inlet valve is the same as that across the cooldown inlet valve (10 psi) values for the flow coefficient can be calculated for the valve when it is both experiencing operating (nominal flow) and cooldown (maximum flow) conditions Again using formula (I) it is found that CVmin=003 and Cvmax=03 (101) A linear plug with a Cv=05 could be used in this application with the valve limited to 112 stroke for improved resolution in operating mode
2 CVI Cryogenic Standard products The Linear Valve Plug is designed to vary the fluid flow in direct proportion to the valve lift throughout the range It is generally recognized as providing the most satisfactory control characteristic for the majority of applications Particularly suitable for high flow rates
6
--~-~ --------shy-
~FL~O~W~S~I~ZI~N~G~C~R~Y~O=S~Y~ST~E~M~V~A~L~V~E~S~_____________________7
Cryostat Loop Outlet Valve
The outlet valve vents the gaseous nitrogen to atmosphere and has a pressure drop of 30 psi It must be able to accommodate a flow range from the nominal value of the operating loops 546 gls (5573 scfh) to the maximum value of the cooldown loops 2184 gls (22292 scfh) By using form ula (IO the range of flow coefficients can be calculated It is found that CVm in=020 and Cvmax=80 (40 1) and the equal percentage plug 12 stroke solution will be applied
Cryostat Gas MakeupReturn Valve The cryostats and the LAr source dewar gas spaces communicate
through a valve that supplies makeup gas to the cryostat on cooldown and condensing and returns gas to the dewar on warmup or above some set pressure during normal operation
The expected makeup and return pressure differences are taken as 5psid the maximum flow the condenser flow to the cryostats is 250 gIs and the minimum flow return under nominal conditions is 625 gs The calculated Cvmax =255 and the Cvm in=064 (401) will require the equal percentage and 112 stroke option
) CONCLUSION
The small Cv values calculated and the large turndown ratios of the valves make the valve and plug selection process difficult The large range of necessary Cv values can be accomplished however by using equal percentage plugs Limiting the stroke of the valves to 50 by controlling the drive signals to 4-12ma (rather than 4-20ma) will allow for closer control of the very low operating flows through increased loop gain This combination of techniques should adequately cover the requirements as described
7
DFL~O~W~SuI~ZI~N~G~C~R~Y~O~S~Y~ST~EwM~VuA~L~VLE~S~_____________________8
--
Appendix I
Control valye Liauid Quality
The inlet liquid enthalpy is related to exit liquid and gas enthalpyies as
where HoPo the inlet sat liquid enthalpy HI P I = the exit liquid enthalpy HgPl = the exit vapor enthalpy
Q = liquid quality = (I-x) x vapor fraction
For the Operating loop-inlet Po 35 atm PI 30 atm
J x = (-95175 98938)(98938 + 84169) 002
see enthalpy vs pressure curve figure 1
The corresponding Cy 1) is only 14 of the that calculated in this report 2) affects only the upper flow limit 3) and will be considered by selecting Cy values 10 to 20 larger than calculated for liquid flow This general conclusion applies to all the applications considered here
Note too that subcooling by 05 atm or more prevents the formation of vapor in this case A gt1 atm subcooler will be considered for the critical cryostat feed manifold application see figure 2
8
LFL~OpoundW~SulkZIuNllG~C~R~Y~O~S~Y~STLE~M~VuA~L~VLE~S~_____________________9
Appendix II
Figures
1 Saturated LN2 Enthalpy 2 Liquid Quality Control
Supporting Graphs and Tabulations
1 Approximate Cv as a function of nominal valve size
2a Valve responses for i quick opening 11 linear ill equal percentage (log)
- titi half stroke equal percentage
J 2b Log plot of
1 2a iii 11 2a iiii
3 Valve sizing Liquid Argon Dewar
4 Valve sizing Cryostat cooling Loops
5 Valve sizing Cryostat gas makeupreturn
9
Saturated LN2 Enthalpy
-80
-90
t)J) 01 -100 - ~
=shy-CS- =
j ~ -110
-120
~ V
V V
~V j V
lI J
V
I
-130
o 1 2 3 4 5 6
Pressure Atm
-~ F-l
)
The sum of the heat leaks to the supply manifold is 1OOW The sub-cooling provided by the source and cooling loop elevation differences is just equal to 100W at a manifold flow of 37 gls Above that flow the liquid quality is 100 GN2 venting or suplimentary subcoolshying is required for smaller flows The calculated steady state manifold flow requirement is 165 gIs requiring a ventlsubcooling flow of 0275 gls (0005gpm)
)
F-2
CV data 5
4
3
2
o 00
I
I
I
~
V~
01 02 03 04 05 06
Diameter in
J
CV data 35
30
25
~ 20Q =rJl 15
U 10
5
0
J
I J
)
~
V ~
lshy00 02 04 06 08 10 12 14 16
I
Diameter in A2-1
-------~--
Valve Responses 100
80
~
= 600 til
-=-0
40 ~ gt= 20
o
I ~ o--7 ~ - V
J 1111 IL
I ~ v V
I ~ lV
~ III ~
V
I l
V II
1 1V
~ V
lV
1 ~V J
o 10 20 30 40 50 60 70 80 90 100
Flow
) A2-2a
Equal Pct (log) Plug
100
90
80
~ 70
= 600til 50 0
=- 40
~ 30-gt= 20
10
I
V J
1
V ~ ~
Vmiddot
l
II
I II
r
I
1
101
Flow
viol
I r
i
--
lL(Q)Sldisect9 VSllive Sizmg
ARGON DEWAR LN2 CONDENSER
LOADS
INLET Nom Range LN2(gs)
(gpm) Cv
)
OUTLET Nom Range GN2(gs)
(sctb) Cv
Notes
Max Min 40kW
100(14) 205 6 054 08
100(14) 205 209k 105 167
410W
1 21 004 0005 0008
1 21 206 010 016
1 Equal percentage (log) plugs
)
Remarks Condensing Steady State
full(hali) stkl
10 LN2 press hi LN2 press
full(half) stkl
10 LN2 press hi LN2 press
~-3
CRYOSTAT COOLING LOOPS
LOADS
CD INLET Range LN2(gs)
(gpm) Cv
OPINLET-) Range
LN2(gs) (gpm)
Cv
OUTLET Range LN2(gs)
(scfh) Cv
Notes
Max
40kW 4 218 433 122
10kW 10(5) 55 108 03
40kW 40(6) 218 22k 80
Min Remarks
10kW 1 linear plug 55 108 03 hi LN2 Press
1kW 1 full(half) stkl 55 011 003 10 LN2 press
1kW 1 full (halt) stkl 55 557 02
~ 1 Equal percentage (log) plugs
)
-~
A2-4
I middot bull
tA JL(Q)adisect9 Valive sectflzllimg
CRYOSTAT GAS MAKEUPIRETURN 1
LOADS Max Min Remarks
asINLET3 40kW 1kW Range 40(6) 1 full(halt) stk2
LAr(gs) 250 625 (scth) 195k 049k
Cv 255 064
--asOUTLET3 5kW 1kW Range 5 1
) LAr(gs) 313 625 (scth) 24k 049k
Cv 32 064
-~
Notes 1a Makeup(cooldown) = Reverse acting b Retum( operate) = Direct acting
2 Equal percentage (log) plugs 3 This is one valve take more severe Inlet service requirements
)
A2-S
~FL~O~W~SuI~ZI~N~G~C~R~Y~O~S~Y~ST~E~M~V~A~L~Y~E~S~_____________________3
- Liquid Argon Condenser Inlet Valve
The pressure drop across the inlet valve is expected to range from a minimum value of 13 atm (195 psid) to a maximum value of 29 atm (435 psid) Minimum and maximum flow coefficients were calculated from these values using the following formula for liquid flow from CVIs Cryogenic Standard Products
Cv - QI(GIAP)O5 (I)
where Cv = Valve Flow Coefficient 6P = Pressure Drop (psi) Ql = Liquid Flow Rate (gpm)
density of subject fluid G = Specific Gravity= density of water
For the maximum cooling rate of 40 kW Cv LP=054 and the Cv HP=08 However when the cooling rate is only 410 W the flow coefficients are significantly smaller with Cv LP=0005 and CV HP=0008 This wide range of desired flow coefficients (100 1 ) necessitates the use of a plug capable of covering a broad spectrum A possible solution is an
J eq ual percentage plug 1 for the full range and 12 stroke valve operation when the operation requires the smaller Cvs for low flow resolution
The installed valve has a flow coefficient of 34 It is necessary to install a new seat and plug that has a Cv 1
Liquid Argon Condenser Outlet Valve
The mass flow rates through the outlet valve are taken to be the same as those used for the inlet valve calculations The associated flow rates are a minimum of 2064 scfh and a maximum of 20950 scfh
The valve vents to atmosphere and again allowing for a range in the pressure of the nitrogen in the cooling loops the pressure drop across the outlet valve can vary from 04 atm (6 psid) to 1 atm (15 psid) These values were used to calculate minimum and maximum flow coefficients
1 CVI Cryogenic Standard Products The Percentage Valve Plug is designed to vary the fluid flow in an equal percentage ratio with each increment of valve lift The Percentage Plug is used in cases where the operating conditions are definitely established before installation or where it is desirable to use a valve larger than
-- would ordinarily be necessary
3
LFL~Q~W~S~I~Z~IN~G~CR~Y~Q~S~Y~SuT~EpoundM~V~A~LuV~E~S_______________________4
using the formula for gaseous flow from CVIs Standard Cryogenic- Products
Cv =(Qg 1391 HTGI APP2o5 (I I)
where Cv == Valve Flow Coefficient 6P = Pressure Drop (p sid) Qg = Gaseous Flow Rate (scfh)
density of subject gas at STP G == Specific Gravity= density of air at STP
T = Absolute Temperature COR) P2 = Downstream pressure (psia)
For the maximum cooling rate of 40 kW CV LP=105 and Cv HP=167 The minimum cooling rate of 410 W results in CV LP=010 and Cv HP=016 The valve mounted in the line has a Cv=34 suitable for the larger Cv calculated However because of the large range between the maximum condenser and quiescent states (1001) the Cv should be changed to 16 and an equal percentage plug with a limited stroke for small Cv values
-- should be used
4
LFL~O~W~SuI~ZliIN~GLkCR~Y~O~SuY~S~T~E~MLLV~A~L~V~E~S_______________________5
- CRYOSTATS
Cryostat Mass Flow Rate
The mass flow rate of nitrogen in the cryostat cooling loops is determined by the required cryostat cooling rate For the cooldown loops the required cooling rate can range from 10 kW to 40 kW With the typical pressure in the loops at 3 atm the range of mass flow is from 55 gls (108 gpm) to 218 gls (433 gpm) The operating loops have a required cooling rate that varies from 1 kW to 10 kW depending upon whether operating or cooldown conditions are being experienced The mass flow rate for the operating loops ranges from 546 gls (0108 gpm) to 546 gls (108 gpm)
Cryostat Line Pressure Drop
In transport from the nitrogen dewar to the cryostats a change in pressure occurs due to the change in elevation and the flow of fluid through a pipe The pressure increase brought about by the change in elevation is 0342 psilft For the 1975 ft elevation difference the increase in pressure head of the liquid is 6754 psi The length of piping to the north end calorimeter (NEC) is used to calculate the pressure drop due to the flow of fluid through a pipe because it has the longest length and thus the largest pressure drop Using 1-12 pipe the length of straight pipe from the nitrogen dewar to the NEC inlet valve is 33703 ft Taking into account the flow through the straight pipe one 45 0 elbow twenty-three 90deg elbows two tees 5 bayonets and two I angle valves the equivalent length of straight pipe becomes 48703 ft The pressure drop due to liquid flow through a pipe at 185e-5 psilft is 90 le-3 psi small in comparison to the pressure increase (subcooling) from the 6745 psi liquid head See Cryostat Liq uid Quality for discussion of the 10 OW line loss generated 05gs gas flow
Cryostat VJ Line Heat Leak
The heat leak experienced in transport through the pipe valves and bayonets is calculated to be 100 W The increase in pressure from the head of the liquid provides a subcooling proportional to the flow rate The heat leak into the system just balances the subcooling if the flow is 37 gs
5
--------~---~--------
r-shy
)
~FL=Q~W~S~I~ZI~N~G~C_R~Y~O=S~Y~ST~E~M~V~A~L~V~E~S~_____________________6
For example a flow of 546 gls produces 149 W of subcoolingwhkh results in a net value of 49 W of the subcooling of the liquid
Cryostat Liquid Quality
Saturated liquid flowing into the cryostat inlet valve experiences a pressure drop of I atm the quality of the liquid entering the cooling loops is 962 (98 for 05 atm) To insure saturated liquid is flowing into the inlet valve after being transported along the piping (I OOW heat loss) from the nitrogen dewar a self-contained gaseous nitrogen vent valve (CVI) can be mounted in the line close to the cryostats to vent any gas present in the line Alternatively a subcooling control valve can be arranged in such a way that it provides a one atmosphere saturated flow through a small line coxial with the cryostat supply manifold and vents to atmosphere Either method would provide the inlet valves with high quality liquid and the latter with a controlled level of subcooling See fig 2
Cryostat Cooldown Loop Inlet Valve
If the dewar pressure is set to 55 psia and a pressure drop of 10 psi is experienced when the liq uid nitrogen passes through the valve the range of flow coefficients calculated range of mass flow rates from 10 kW to 40kW Using formula (I) to calculate the flow coefficients Cvmin=03 and Cvmax= 122 Since the flow coefficient bounds differ only by a factor of four a linear plug 2 with a Cv = 15 would be appropriate for this application
Cryostat Operating Loop Inlet Valve
If the pressure drop across the operating inlet valve is the same as that across the cooldown inlet valve (10 psi) values for the flow coefficient can be calculated for the valve when it is both experiencing operating (nominal flow) and cooldown (maximum flow) conditions Again using formula (I) it is found that CVmin=003 and Cvmax=03 (101) A linear plug with a Cv=05 could be used in this application with the valve limited to 112 stroke for improved resolution in operating mode
2 CVI Cryogenic Standard products The Linear Valve Plug is designed to vary the fluid flow in direct proportion to the valve lift throughout the range It is generally recognized as providing the most satisfactory control characteristic for the majority of applications Particularly suitable for high flow rates
6
--~-~ --------shy-
~FL~O~W~S~I~ZI~N~G~C~R~Y~O=S~Y~ST~E~M~V~A~L~V~E~S~_____________________7
Cryostat Loop Outlet Valve
The outlet valve vents the gaseous nitrogen to atmosphere and has a pressure drop of 30 psi It must be able to accommodate a flow range from the nominal value of the operating loops 546 gls (5573 scfh) to the maximum value of the cooldown loops 2184 gls (22292 scfh) By using form ula (IO the range of flow coefficients can be calculated It is found that CVm in=020 and Cvmax=80 (40 1) and the equal percentage plug 12 stroke solution will be applied
Cryostat Gas MakeupReturn Valve The cryostats and the LAr source dewar gas spaces communicate
through a valve that supplies makeup gas to the cryostat on cooldown and condensing and returns gas to the dewar on warmup or above some set pressure during normal operation
The expected makeup and return pressure differences are taken as 5psid the maximum flow the condenser flow to the cryostats is 250 gIs and the minimum flow return under nominal conditions is 625 gs The calculated Cvmax =255 and the Cvm in=064 (401) will require the equal percentage and 112 stroke option
) CONCLUSION
The small Cv values calculated and the large turndown ratios of the valves make the valve and plug selection process difficult The large range of necessary Cv values can be accomplished however by using equal percentage plugs Limiting the stroke of the valves to 50 by controlling the drive signals to 4-12ma (rather than 4-20ma) will allow for closer control of the very low operating flows through increased loop gain This combination of techniques should adequately cover the requirements as described
7
DFL~O~W~SuI~ZI~N~G~C~R~Y~O~S~Y~ST~EwM~VuA~L~VLE~S~_____________________8
--
Appendix I
Control valye Liauid Quality
The inlet liquid enthalpy is related to exit liquid and gas enthalpyies as
where HoPo the inlet sat liquid enthalpy HI P I = the exit liquid enthalpy HgPl = the exit vapor enthalpy
Q = liquid quality = (I-x) x vapor fraction
For the Operating loop-inlet Po 35 atm PI 30 atm
J x = (-95175 98938)(98938 + 84169) 002
see enthalpy vs pressure curve figure 1
The corresponding Cy 1) is only 14 of the that calculated in this report 2) affects only the upper flow limit 3) and will be considered by selecting Cy values 10 to 20 larger than calculated for liquid flow This general conclusion applies to all the applications considered here
Note too that subcooling by 05 atm or more prevents the formation of vapor in this case A gt1 atm subcooler will be considered for the critical cryostat feed manifold application see figure 2
8
LFL~OpoundW~SulkZIuNllG~C~R~Y~O~S~Y~STLE~M~VuA~L~VLE~S~_____________________9
Appendix II
Figures
1 Saturated LN2 Enthalpy 2 Liquid Quality Control
Supporting Graphs and Tabulations
1 Approximate Cv as a function of nominal valve size
2a Valve responses for i quick opening 11 linear ill equal percentage (log)
- titi half stroke equal percentage
J 2b Log plot of
1 2a iii 11 2a iiii
3 Valve sizing Liquid Argon Dewar
4 Valve sizing Cryostat cooling Loops
5 Valve sizing Cryostat gas makeupreturn
9
Saturated LN2 Enthalpy
-80
-90
t)J) 01 -100 - ~
=shy-CS- =
j ~ -110
-120
~ V
V V
~V j V
lI J
V
I
-130
o 1 2 3 4 5 6
Pressure Atm
-~ F-l
)
The sum of the heat leaks to the supply manifold is 1OOW The sub-cooling provided by the source and cooling loop elevation differences is just equal to 100W at a manifold flow of 37 gls Above that flow the liquid quality is 100 GN2 venting or suplimentary subcoolshying is required for smaller flows The calculated steady state manifold flow requirement is 165 gIs requiring a ventlsubcooling flow of 0275 gls (0005gpm)
)
F-2
CV data 5
4
3
2
o 00
I
I
I
~
V~
01 02 03 04 05 06
Diameter in
J
CV data 35
30
25
~ 20Q =rJl 15
U 10
5
0
J
I J
)
~
V ~
lshy00 02 04 06 08 10 12 14 16
I
Diameter in A2-1
-------~--
Valve Responses 100
80
~
= 600 til
-=-0
40 ~ gt= 20
o
I ~ o--7 ~ - V
J 1111 IL
I ~ v V
I ~ lV
~ III ~
V
I l
V II
1 1V
~ V
lV
1 ~V J
o 10 20 30 40 50 60 70 80 90 100
Flow
) A2-2a
Equal Pct (log) Plug
100
90
80
~ 70
= 600til 50 0
=- 40
~ 30-gt= 20
10
I
V J
1
V ~ ~
Vmiddot
l
II
I II
r
I
1
101
Flow
viol
I r
i
--
lL(Q)Sldisect9 VSllive Sizmg
ARGON DEWAR LN2 CONDENSER
LOADS
INLET Nom Range LN2(gs)
(gpm) Cv
)
OUTLET Nom Range GN2(gs)
(sctb) Cv
Notes
Max Min 40kW
100(14) 205 6 054 08
100(14) 205 209k 105 167
410W
1 21 004 0005 0008
1 21 206 010 016
1 Equal percentage (log) plugs
)
Remarks Condensing Steady State
full(hali) stkl
10 LN2 press hi LN2 press
full(half) stkl
10 LN2 press hi LN2 press
~-3
CRYOSTAT COOLING LOOPS
LOADS
CD INLET Range LN2(gs)
(gpm) Cv
OPINLET-) Range
LN2(gs) (gpm)
Cv
OUTLET Range LN2(gs)
(scfh) Cv
Notes
Max
40kW 4 218 433 122
10kW 10(5) 55 108 03
40kW 40(6) 218 22k 80
Min Remarks
10kW 1 linear plug 55 108 03 hi LN2 Press
1kW 1 full(half) stkl 55 011 003 10 LN2 press
1kW 1 full (halt) stkl 55 557 02
~ 1 Equal percentage (log) plugs
)
-~
A2-4
I middot bull
tA JL(Q)adisect9 Valive sectflzllimg
CRYOSTAT GAS MAKEUPIRETURN 1
LOADS Max Min Remarks
asINLET3 40kW 1kW Range 40(6) 1 full(halt) stk2
LAr(gs) 250 625 (scth) 195k 049k
Cv 255 064
--asOUTLET3 5kW 1kW Range 5 1
) LAr(gs) 313 625 (scth) 24k 049k
Cv 32 064
-~
Notes 1a Makeup(cooldown) = Reverse acting b Retum( operate) = Direct acting
2 Equal percentage (log) plugs 3 This is one valve take more severe Inlet service requirements
)
A2-S
LFL~Q~W~S~I~Z~IN~G~CR~Y~Q~S~Y~SuT~EpoundM~V~A~LuV~E~S_______________________4
using the formula for gaseous flow from CVIs Standard Cryogenic- Products
Cv =(Qg 1391 HTGI APP2o5 (I I)
where Cv == Valve Flow Coefficient 6P = Pressure Drop (p sid) Qg = Gaseous Flow Rate (scfh)
density of subject gas at STP G == Specific Gravity= density of air at STP
T = Absolute Temperature COR) P2 = Downstream pressure (psia)
For the maximum cooling rate of 40 kW CV LP=105 and Cv HP=167 The minimum cooling rate of 410 W results in CV LP=010 and Cv HP=016 The valve mounted in the line has a Cv=34 suitable for the larger Cv calculated However because of the large range between the maximum condenser and quiescent states (1001) the Cv should be changed to 16 and an equal percentage plug with a limited stroke for small Cv values
-- should be used
4
LFL~O~W~SuI~ZliIN~GLkCR~Y~O~SuY~S~T~E~MLLV~A~L~V~E~S_______________________5
- CRYOSTATS
Cryostat Mass Flow Rate
The mass flow rate of nitrogen in the cryostat cooling loops is determined by the required cryostat cooling rate For the cooldown loops the required cooling rate can range from 10 kW to 40 kW With the typical pressure in the loops at 3 atm the range of mass flow is from 55 gls (108 gpm) to 218 gls (433 gpm) The operating loops have a required cooling rate that varies from 1 kW to 10 kW depending upon whether operating or cooldown conditions are being experienced The mass flow rate for the operating loops ranges from 546 gls (0108 gpm) to 546 gls (108 gpm)
Cryostat Line Pressure Drop
In transport from the nitrogen dewar to the cryostats a change in pressure occurs due to the change in elevation and the flow of fluid through a pipe The pressure increase brought about by the change in elevation is 0342 psilft For the 1975 ft elevation difference the increase in pressure head of the liquid is 6754 psi The length of piping to the north end calorimeter (NEC) is used to calculate the pressure drop due to the flow of fluid through a pipe because it has the longest length and thus the largest pressure drop Using 1-12 pipe the length of straight pipe from the nitrogen dewar to the NEC inlet valve is 33703 ft Taking into account the flow through the straight pipe one 45 0 elbow twenty-three 90deg elbows two tees 5 bayonets and two I angle valves the equivalent length of straight pipe becomes 48703 ft The pressure drop due to liquid flow through a pipe at 185e-5 psilft is 90 le-3 psi small in comparison to the pressure increase (subcooling) from the 6745 psi liquid head See Cryostat Liq uid Quality for discussion of the 10 OW line loss generated 05gs gas flow
Cryostat VJ Line Heat Leak
The heat leak experienced in transport through the pipe valves and bayonets is calculated to be 100 W The increase in pressure from the head of the liquid provides a subcooling proportional to the flow rate The heat leak into the system just balances the subcooling if the flow is 37 gs
5
--------~---~--------
r-shy
)
~FL=Q~W~S~I~ZI~N~G~C_R~Y~O=S~Y~ST~E~M~V~A~L~V~E~S~_____________________6
For example a flow of 546 gls produces 149 W of subcoolingwhkh results in a net value of 49 W of the subcooling of the liquid
Cryostat Liquid Quality
Saturated liquid flowing into the cryostat inlet valve experiences a pressure drop of I atm the quality of the liquid entering the cooling loops is 962 (98 for 05 atm) To insure saturated liquid is flowing into the inlet valve after being transported along the piping (I OOW heat loss) from the nitrogen dewar a self-contained gaseous nitrogen vent valve (CVI) can be mounted in the line close to the cryostats to vent any gas present in the line Alternatively a subcooling control valve can be arranged in such a way that it provides a one atmosphere saturated flow through a small line coxial with the cryostat supply manifold and vents to atmosphere Either method would provide the inlet valves with high quality liquid and the latter with a controlled level of subcooling See fig 2
Cryostat Cooldown Loop Inlet Valve
If the dewar pressure is set to 55 psia and a pressure drop of 10 psi is experienced when the liq uid nitrogen passes through the valve the range of flow coefficients calculated range of mass flow rates from 10 kW to 40kW Using formula (I) to calculate the flow coefficients Cvmin=03 and Cvmax= 122 Since the flow coefficient bounds differ only by a factor of four a linear plug 2 with a Cv = 15 would be appropriate for this application
Cryostat Operating Loop Inlet Valve
If the pressure drop across the operating inlet valve is the same as that across the cooldown inlet valve (10 psi) values for the flow coefficient can be calculated for the valve when it is both experiencing operating (nominal flow) and cooldown (maximum flow) conditions Again using formula (I) it is found that CVmin=003 and Cvmax=03 (101) A linear plug with a Cv=05 could be used in this application with the valve limited to 112 stroke for improved resolution in operating mode
2 CVI Cryogenic Standard products The Linear Valve Plug is designed to vary the fluid flow in direct proportion to the valve lift throughout the range It is generally recognized as providing the most satisfactory control characteristic for the majority of applications Particularly suitable for high flow rates
6
--~-~ --------shy-
~FL~O~W~S~I~ZI~N~G~C~R~Y~O=S~Y~ST~E~M~V~A~L~V~E~S~_____________________7
Cryostat Loop Outlet Valve
The outlet valve vents the gaseous nitrogen to atmosphere and has a pressure drop of 30 psi It must be able to accommodate a flow range from the nominal value of the operating loops 546 gls (5573 scfh) to the maximum value of the cooldown loops 2184 gls (22292 scfh) By using form ula (IO the range of flow coefficients can be calculated It is found that CVm in=020 and Cvmax=80 (40 1) and the equal percentage plug 12 stroke solution will be applied
Cryostat Gas MakeupReturn Valve The cryostats and the LAr source dewar gas spaces communicate
through a valve that supplies makeup gas to the cryostat on cooldown and condensing and returns gas to the dewar on warmup or above some set pressure during normal operation
The expected makeup and return pressure differences are taken as 5psid the maximum flow the condenser flow to the cryostats is 250 gIs and the minimum flow return under nominal conditions is 625 gs The calculated Cvmax =255 and the Cvm in=064 (401) will require the equal percentage and 112 stroke option
) CONCLUSION
The small Cv values calculated and the large turndown ratios of the valves make the valve and plug selection process difficult The large range of necessary Cv values can be accomplished however by using equal percentage plugs Limiting the stroke of the valves to 50 by controlling the drive signals to 4-12ma (rather than 4-20ma) will allow for closer control of the very low operating flows through increased loop gain This combination of techniques should adequately cover the requirements as described
7
DFL~O~W~SuI~ZI~N~G~C~R~Y~O~S~Y~ST~EwM~VuA~L~VLE~S~_____________________8
--
Appendix I
Control valye Liauid Quality
The inlet liquid enthalpy is related to exit liquid and gas enthalpyies as
where HoPo the inlet sat liquid enthalpy HI P I = the exit liquid enthalpy HgPl = the exit vapor enthalpy
Q = liquid quality = (I-x) x vapor fraction
For the Operating loop-inlet Po 35 atm PI 30 atm
J x = (-95175 98938)(98938 + 84169) 002
see enthalpy vs pressure curve figure 1
The corresponding Cy 1) is only 14 of the that calculated in this report 2) affects only the upper flow limit 3) and will be considered by selecting Cy values 10 to 20 larger than calculated for liquid flow This general conclusion applies to all the applications considered here
Note too that subcooling by 05 atm or more prevents the formation of vapor in this case A gt1 atm subcooler will be considered for the critical cryostat feed manifold application see figure 2
8
LFL~OpoundW~SulkZIuNllG~C~R~Y~O~S~Y~STLE~M~VuA~L~VLE~S~_____________________9
Appendix II
Figures
1 Saturated LN2 Enthalpy 2 Liquid Quality Control
Supporting Graphs and Tabulations
1 Approximate Cv as a function of nominal valve size
2a Valve responses for i quick opening 11 linear ill equal percentage (log)
- titi half stroke equal percentage
J 2b Log plot of
1 2a iii 11 2a iiii
3 Valve sizing Liquid Argon Dewar
4 Valve sizing Cryostat cooling Loops
5 Valve sizing Cryostat gas makeupreturn
9
Saturated LN2 Enthalpy
-80
-90
t)J) 01 -100 - ~
=shy-CS- =
j ~ -110
-120
~ V
V V
~V j V
lI J
V
I
-130
o 1 2 3 4 5 6
Pressure Atm
-~ F-l
)
The sum of the heat leaks to the supply manifold is 1OOW The sub-cooling provided by the source and cooling loop elevation differences is just equal to 100W at a manifold flow of 37 gls Above that flow the liquid quality is 100 GN2 venting or suplimentary subcoolshying is required for smaller flows The calculated steady state manifold flow requirement is 165 gIs requiring a ventlsubcooling flow of 0275 gls (0005gpm)
)
F-2
CV data 5
4
3
2
o 00
I
I
I
~
V~
01 02 03 04 05 06
Diameter in
J
CV data 35
30
25
~ 20Q =rJl 15
U 10
5
0
J
I J
)
~
V ~
lshy00 02 04 06 08 10 12 14 16
I
Diameter in A2-1
-------~--
Valve Responses 100
80
~
= 600 til
-=-0
40 ~ gt= 20
o
I ~ o--7 ~ - V
J 1111 IL
I ~ v V
I ~ lV
~ III ~
V
I l
V II
1 1V
~ V
lV
1 ~V J
o 10 20 30 40 50 60 70 80 90 100
Flow
) A2-2a
Equal Pct (log) Plug
100
90
80
~ 70
= 600til 50 0
=- 40
~ 30-gt= 20
10
I
V J
1
V ~ ~
Vmiddot
l
II
I II
r
I
1
101
Flow
viol
I r
i
--
lL(Q)Sldisect9 VSllive Sizmg
ARGON DEWAR LN2 CONDENSER
LOADS
INLET Nom Range LN2(gs)
(gpm) Cv
)
OUTLET Nom Range GN2(gs)
(sctb) Cv
Notes
Max Min 40kW
100(14) 205 6 054 08
100(14) 205 209k 105 167
410W
1 21 004 0005 0008
1 21 206 010 016
1 Equal percentage (log) plugs
)
Remarks Condensing Steady State
full(hali) stkl
10 LN2 press hi LN2 press
full(half) stkl
10 LN2 press hi LN2 press
~-3
CRYOSTAT COOLING LOOPS
LOADS
CD INLET Range LN2(gs)
(gpm) Cv
OPINLET-) Range
LN2(gs) (gpm)
Cv
OUTLET Range LN2(gs)
(scfh) Cv
Notes
Max
40kW 4 218 433 122
10kW 10(5) 55 108 03
40kW 40(6) 218 22k 80
Min Remarks
10kW 1 linear plug 55 108 03 hi LN2 Press
1kW 1 full(half) stkl 55 011 003 10 LN2 press
1kW 1 full (halt) stkl 55 557 02
~ 1 Equal percentage (log) plugs
)
-~
A2-4
I middot bull
tA JL(Q)adisect9 Valive sectflzllimg
CRYOSTAT GAS MAKEUPIRETURN 1
LOADS Max Min Remarks
asINLET3 40kW 1kW Range 40(6) 1 full(halt) stk2
LAr(gs) 250 625 (scth) 195k 049k
Cv 255 064
--asOUTLET3 5kW 1kW Range 5 1
) LAr(gs) 313 625 (scth) 24k 049k
Cv 32 064
-~
Notes 1a Makeup(cooldown) = Reverse acting b Retum( operate) = Direct acting
2 Equal percentage (log) plugs 3 This is one valve take more severe Inlet service requirements
)
A2-S
LFL~O~W~SuI~ZliIN~GLkCR~Y~O~SuY~S~T~E~MLLV~A~L~V~E~S_______________________5
- CRYOSTATS
Cryostat Mass Flow Rate
The mass flow rate of nitrogen in the cryostat cooling loops is determined by the required cryostat cooling rate For the cooldown loops the required cooling rate can range from 10 kW to 40 kW With the typical pressure in the loops at 3 atm the range of mass flow is from 55 gls (108 gpm) to 218 gls (433 gpm) The operating loops have a required cooling rate that varies from 1 kW to 10 kW depending upon whether operating or cooldown conditions are being experienced The mass flow rate for the operating loops ranges from 546 gls (0108 gpm) to 546 gls (108 gpm)
Cryostat Line Pressure Drop
In transport from the nitrogen dewar to the cryostats a change in pressure occurs due to the change in elevation and the flow of fluid through a pipe The pressure increase brought about by the change in elevation is 0342 psilft For the 1975 ft elevation difference the increase in pressure head of the liquid is 6754 psi The length of piping to the north end calorimeter (NEC) is used to calculate the pressure drop due to the flow of fluid through a pipe because it has the longest length and thus the largest pressure drop Using 1-12 pipe the length of straight pipe from the nitrogen dewar to the NEC inlet valve is 33703 ft Taking into account the flow through the straight pipe one 45 0 elbow twenty-three 90deg elbows two tees 5 bayonets and two I angle valves the equivalent length of straight pipe becomes 48703 ft The pressure drop due to liquid flow through a pipe at 185e-5 psilft is 90 le-3 psi small in comparison to the pressure increase (subcooling) from the 6745 psi liquid head See Cryostat Liq uid Quality for discussion of the 10 OW line loss generated 05gs gas flow
Cryostat VJ Line Heat Leak
The heat leak experienced in transport through the pipe valves and bayonets is calculated to be 100 W The increase in pressure from the head of the liquid provides a subcooling proportional to the flow rate The heat leak into the system just balances the subcooling if the flow is 37 gs
5
--------~---~--------
r-shy
)
~FL=Q~W~S~I~ZI~N~G~C_R~Y~O=S~Y~ST~E~M~V~A~L~V~E~S~_____________________6
For example a flow of 546 gls produces 149 W of subcoolingwhkh results in a net value of 49 W of the subcooling of the liquid
Cryostat Liquid Quality
Saturated liquid flowing into the cryostat inlet valve experiences a pressure drop of I atm the quality of the liquid entering the cooling loops is 962 (98 for 05 atm) To insure saturated liquid is flowing into the inlet valve after being transported along the piping (I OOW heat loss) from the nitrogen dewar a self-contained gaseous nitrogen vent valve (CVI) can be mounted in the line close to the cryostats to vent any gas present in the line Alternatively a subcooling control valve can be arranged in such a way that it provides a one atmosphere saturated flow through a small line coxial with the cryostat supply manifold and vents to atmosphere Either method would provide the inlet valves with high quality liquid and the latter with a controlled level of subcooling See fig 2
Cryostat Cooldown Loop Inlet Valve
If the dewar pressure is set to 55 psia and a pressure drop of 10 psi is experienced when the liq uid nitrogen passes through the valve the range of flow coefficients calculated range of mass flow rates from 10 kW to 40kW Using formula (I) to calculate the flow coefficients Cvmin=03 and Cvmax= 122 Since the flow coefficient bounds differ only by a factor of four a linear plug 2 with a Cv = 15 would be appropriate for this application
Cryostat Operating Loop Inlet Valve
If the pressure drop across the operating inlet valve is the same as that across the cooldown inlet valve (10 psi) values for the flow coefficient can be calculated for the valve when it is both experiencing operating (nominal flow) and cooldown (maximum flow) conditions Again using formula (I) it is found that CVmin=003 and Cvmax=03 (101) A linear plug with a Cv=05 could be used in this application with the valve limited to 112 stroke for improved resolution in operating mode
2 CVI Cryogenic Standard products The Linear Valve Plug is designed to vary the fluid flow in direct proportion to the valve lift throughout the range It is generally recognized as providing the most satisfactory control characteristic for the majority of applications Particularly suitable for high flow rates
6
--~-~ --------shy-
~FL~O~W~S~I~ZI~N~G~C~R~Y~O=S~Y~ST~E~M~V~A~L~V~E~S~_____________________7
Cryostat Loop Outlet Valve
The outlet valve vents the gaseous nitrogen to atmosphere and has a pressure drop of 30 psi It must be able to accommodate a flow range from the nominal value of the operating loops 546 gls (5573 scfh) to the maximum value of the cooldown loops 2184 gls (22292 scfh) By using form ula (IO the range of flow coefficients can be calculated It is found that CVm in=020 and Cvmax=80 (40 1) and the equal percentage plug 12 stroke solution will be applied
Cryostat Gas MakeupReturn Valve The cryostats and the LAr source dewar gas spaces communicate
through a valve that supplies makeup gas to the cryostat on cooldown and condensing and returns gas to the dewar on warmup or above some set pressure during normal operation
The expected makeup and return pressure differences are taken as 5psid the maximum flow the condenser flow to the cryostats is 250 gIs and the minimum flow return under nominal conditions is 625 gs The calculated Cvmax =255 and the Cvm in=064 (401) will require the equal percentage and 112 stroke option
) CONCLUSION
The small Cv values calculated and the large turndown ratios of the valves make the valve and plug selection process difficult The large range of necessary Cv values can be accomplished however by using equal percentage plugs Limiting the stroke of the valves to 50 by controlling the drive signals to 4-12ma (rather than 4-20ma) will allow for closer control of the very low operating flows through increased loop gain This combination of techniques should adequately cover the requirements as described
7
DFL~O~W~SuI~ZI~N~G~C~R~Y~O~S~Y~ST~EwM~VuA~L~VLE~S~_____________________8
--
Appendix I
Control valye Liauid Quality
The inlet liquid enthalpy is related to exit liquid and gas enthalpyies as
where HoPo the inlet sat liquid enthalpy HI P I = the exit liquid enthalpy HgPl = the exit vapor enthalpy
Q = liquid quality = (I-x) x vapor fraction
For the Operating loop-inlet Po 35 atm PI 30 atm
J x = (-95175 98938)(98938 + 84169) 002
see enthalpy vs pressure curve figure 1
The corresponding Cy 1) is only 14 of the that calculated in this report 2) affects only the upper flow limit 3) and will be considered by selecting Cy values 10 to 20 larger than calculated for liquid flow This general conclusion applies to all the applications considered here
Note too that subcooling by 05 atm or more prevents the formation of vapor in this case A gt1 atm subcooler will be considered for the critical cryostat feed manifold application see figure 2
8
LFL~OpoundW~SulkZIuNllG~C~R~Y~O~S~Y~STLE~M~VuA~L~VLE~S~_____________________9
Appendix II
Figures
1 Saturated LN2 Enthalpy 2 Liquid Quality Control
Supporting Graphs and Tabulations
1 Approximate Cv as a function of nominal valve size
2a Valve responses for i quick opening 11 linear ill equal percentage (log)
- titi half stroke equal percentage
J 2b Log plot of
1 2a iii 11 2a iiii
3 Valve sizing Liquid Argon Dewar
4 Valve sizing Cryostat cooling Loops
5 Valve sizing Cryostat gas makeupreturn
9
Saturated LN2 Enthalpy
-80
-90
t)J) 01 -100 - ~
=shy-CS- =
j ~ -110
-120
~ V
V V
~V j V
lI J
V
I
-130
o 1 2 3 4 5 6
Pressure Atm
-~ F-l
)
The sum of the heat leaks to the supply manifold is 1OOW The sub-cooling provided by the source and cooling loop elevation differences is just equal to 100W at a manifold flow of 37 gls Above that flow the liquid quality is 100 GN2 venting or suplimentary subcoolshying is required for smaller flows The calculated steady state manifold flow requirement is 165 gIs requiring a ventlsubcooling flow of 0275 gls (0005gpm)
)
F-2
CV data 5
4
3
2
o 00
I
I
I
~
V~
01 02 03 04 05 06
Diameter in
J
CV data 35
30
25
~ 20Q =rJl 15
U 10
5
0
J
I J
)
~
V ~
lshy00 02 04 06 08 10 12 14 16
I
Diameter in A2-1
-------~--
Valve Responses 100
80
~
= 600 til
-=-0
40 ~ gt= 20
o
I ~ o--7 ~ - V
J 1111 IL
I ~ v V
I ~ lV
~ III ~
V
I l
V II
1 1V
~ V
lV
1 ~V J
o 10 20 30 40 50 60 70 80 90 100
Flow
) A2-2a
Equal Pct (log) Plug
100
90
80
~ 70
= 600til 50 0
=- 40
~ 30-gt= 20
10
I
V J
1
V ~ ~
Vmiddot
l
II
I II
r
I
1
101
Flow
viol
I r
i
--
lL(Q)Sldisect9 VSllive Sizmg
ARGON DEWAR LN2 CONDENSER
LOADS
INLET Nom Range LN2(gs)
(gpm) Cv
)
OUTLET Nom Range GN2(gs)
(sctb) Cv
Notes
Max Min 40kW
100(14) 205 6 054 08
100(14) 205 209k 105 167
410W
1 21 004 0005 0008
1 21 206 010 016
1 Equal percentage (log) plugs
)
Remarks Condensing Steady State
full(hali) stkl
10 LN2 press hi LN2 press
full(half) stkl
10 LN2 press hi LN2 press
~-3
CRYOSTAT COOLING LOOPS
LOADS
CD INLET Range LN2(gs)
(gpm) Cv
OPINLET-) Range
LN2(gs) (gpm)
Cv
OUTLET Range LN2(gs)
(scfh) Cv
Notes
Max
40kW 4 218 433 122
10kW 10(5) 55 108 03
40kW 40(6) 218 22k 80
Min Remarks
10kW 1 linear plug 55 108 03 hi LN2 Press
1kW 1 full(half) stkl 55 011 003 10 LN2 press
1kW 1 full (halt) stkl 55 557 02
~ 1 Equal percentage (log) plugs
)
-~
A2-4
I middot bull
tA JL(Q)adisect9 Valive sectflzllimg
CRYOSTAT GAS MAKEUPIRETURN 1
LOADS Max Min Remarks
asINLET3 40kW 1kW Range 40(6) 1 full(halt) stk2
LAr(gs) 250 625 (scth) 195k 049k
Cv 255 064
--asOUTLET3 5kW 1kW Range 5 1
) LAr(gs) 313 625 (scth) 24k 049k
Cv 32 064
-~
Notes 1a Makeup(cooldown) = Reverse acting b Retum( operate) = Direct acting
2 Equal percentage (log) plugs 3 This is one valve take more severe Inlet service requirements
)
A2-S
r-shy
)
~FL=Q~W~S~I~ZI~N~G~C_R~Y~O=S~Y~ST~E~M~V~A~L~V~E~S~_____________________6
For example a flow of 546 gls produces 149 W of subcoolingwhkh results in a net value of 49 W of the subcooling of the liquid
Cryostat Liquid Quality
Saturated liquid flowing into the cryostat inlet valve experiences a pressure drop of I atm the quality of the liquid entering the cooling loops is 962 (98 for 05 atm) To insure saturated liquid is flowing into the inlet valve after being transported along the piping (I OOW heat loss) from the nitrogen dewar a self-contained gaseous nitrogen vent valve (CVI) can be mounted in the line close to the cryostats to vent any gas present in the line Alternatively a subcooling control valve can be arranged in such a way that it provides a one atmosphere saturated flow through a small line coxial with the cryostat supply manifold and vents to atmosphere Either method would provide the inlet valves with high quality liquid and the latter with a controlled level of subcooling See fig 2
Cryostat Cooldown Loop Inlet Valve
If the dewar pressure is set to 55 psia and a pressure drop of 10 psi is experienced when the liq uid nitrogen passes through the valve the range of flow coefficients calculated range of mass flow rates from 10 kW to 40kW Using formula (I) to calculate the flow coefficients Cvmin=03 and Cvmax= 122 Since the flow coefficient bounds differ only by a factor of four a linear plug 2 with a Cv = 15 would be appropriate for this application
Cryostat Operating Loop Inlet Valve
If the pressure drop across the operating inlet valve is the same as that across the cooldown inlet valve (10 psi) values for the flow coefficient can be calculated for the valve when it is both experiencing operating (nominal flow) and cooldown (maximum flow) conditions Again using formula (I) it is found that CVmin=003 and Cvmax=03 (101) A linear plug with a Cv=05 could be used in this application with the valve limited to 112 stroke for improved resolution in operating mode
2 CVI Cryogenic Standard products The Linear Valve Plug is designed to vary the fluid flow in direct proportion to the valve lift throughout the range It is generally recognized as providing the most satisfactory control characteristic for the majority of applications Particularly suitable for high flow rates
6
--~-~ --------shy-
~FL~O~W~S~I~ZI~N~G~C~R~Y~O=S~Y~ST~E~M~V~A~L~V~E~S~_____________________7
Cryostat Loop Outlet Valve
The outlet valve vents the gaseous nitrogen to atmosphere and has a pressure drop of 30 psi It must be able to accommodate a flow range from the nominal value of the operating loops 546 gls (5573 scfh) to the maximum value of the cooldown loops 2184 gls (22292 scfh) By using form ula (IO the range of flow coefficients can be calculated It is found that CVm in=020 and Cvmax=80 (40 1) and the equal percentage plug 12 stroke solution will be applied
Cryostat Gas MakeupReturn Valve The cryostats and the LAr source dewar gas spaces communicate
through a valve that supplies makeup gas to the cryostat on cooldown and condensing and returns gas to the dewar on warmup or above some set pressure during normal operation
The expected makeup and return pressure differences are taken as 5psid the maximum flow the condenser flow to the cryostats is 250 gIs and the minimum flow return under nominal conditions is 625 gs The calculated Cvmax =255 and the Cvm in=064 (401) will require the equal percentage and 112 stroke option
) CONCLUSION
The small Cv values calculated and the large turndown ratios of the valves make the valve and plug selection process difficult The large range of necessary Cv values can be accomplished however by using equal percentage plugs Limiting the stroke of the valves to 50 by controlling the drive signals to 4-12ma (rather than 4-20ma) will allow for closer control of the very low operating flows through increased loop gain This combination of techniques should adequately cover the requirements as described
7
DFL~O~W~SuI~ZI~N~G~C~R~Y~O~S~Y~ST~EwM~VuA~L~VLE~S~_____________________8
--
Appendix I
Control valye Liauid Quality
The inlet liquid enthalpy is related to exit liquid and gas enthalpyies as
where HoPo the inlet sat liquid enthalpy HI P I = the exit liquid enthalpy HgPl = the exit vapor enthalpy
Q = liquid quality = (I-x) x vapor fraction
For the Operating loop-inlet Po 35 atm PI 30 atm
J x = (-95175 98938)(98938 + 84169) 002
see enthalpy vs pressure curve figure 1
The corresponding Cy 1) is only 14 of the that calculated in this report 2) affects only the upper flow limit 3) and will be considered by selecting Cy values 10 to 20 larger than calculated for liquid flow This general conclusion applies to all the applications considered here
Note too that subcooling by 05 atm or more prevents the formation of vapor in this case A gt1 atm subcooler will be considered for the critical cryostat feed manifold application see figure 2
8
LFL~OpoundW~SulkZIuNllG~C~R~Y~O~S~Y~STLE~M~VuA~L~VLE~S~_____________________9
Appendix II
Figures
1 Saturated LN2 Enthalpy 2 Liquid Quality Control
Supporting Graphs and Tabulations
1 Approximate Cv as a function of nominal valve size
2a Valve responses for i quick opening 11 linear ill equal percentage (log)
- titi half stroke equal percentage
J 2b Log plot of
1 2a iii 11 2a iiii
3 Valve sizing Liquid Argon Dewar
4 Valve sizing Cryostat cooling Loops
5 Valve sizing Cryostat gas makeupreturn
9
Saturated LN2 Enthalpy
-80
-90
t)J) 01 -100 - ~
=shy-CS- =
j ~ -110
-120
~ V
V V
~V j V
lI J
V
I
-130
o 1 2 3 4 5 6
Pressure Atm
-~ F-l
)
The sum of the heat leaks to the supply manifold is 1OOW The sub-cooling provided by the source and cooling loop elevation differences is just equal to 100W at a manifold flow of 37 gls Above that flow the liquid quality is 100 GN2 venting or suplimentary subcoolshying is required for smaller flows The calculated steady state manifold flow requirement is 165 gIs requiring a ventlsubcooling flow of 0275 gls (0005gpm)
)
F-2
CV data 5
4
3
2
o 00
I
I
I
~
V~
01 02 03 04 05 06
Diameter in
J
CV data 35
30
25
~ 20Q =rJl 15
U 10
5
0
J
I J
)
~
V ~
lshy00 02 04 06 08 10 12 14 16
I
Diameter in A2-1
-------~--
Valve Responses 100
80
~
= 600 til
-=-0
40 ~ gt= 20
o
I ~ o--7 ~ - V
J 1111 IL
I ~ v V
I ~ lV
~ III ~
V
I l
V II
1 1V
~ V
lV
1 ~V J
o 10 20 30 40 50 60 70 80 90 100
Flow
) A2-2a
Equal Pct (log) Plug
100
90
80
~ 70
= 600til 50 0
=- 40
~ 30-gt= 20
10
I
V J
1
V ~ ~
Vmiddot
l
II
I II
r
I
1
101
Flow
viol
I r
i
--
lL(Q)Sldisect9 VSllive Sizmg
ARGON DEWAR LN2 CONDENSER
LOADS
INLET Nom Range LN2(gs)
(gpm) Cv
)
OUTLET Nom Range GN2(gs)
(sctb) Cv
Notes
Max Min 40kW
100(14) 205 6 054 08
100(14) 205 209k 105 167
410W
1 21 004 0005 0008
1 21 206 010 016
1 Equal percentage (log) plugs
)
Remarks Condensing Steady State
full(hali) stkl
10 LN2 press hi LN2 press
full(half) stkl
10 LN2 press hi LN2 press
~-3
CRYOSTAT COOLING LOOPS
LOADS
CD INLET Range LN2(gs)
(gpm) Cv
OPINLET-) Range
LN2(gs) (gpm)
Cv
OUTLET Range LN2(gs)
(scfh) Cv
Notes
Max
40kW 4 218 433 122
10kW 10(5) 55 108 03
40kW 40(6) 218 22k 80
Min Remarks
10kW 1 linear plug 55 108 03 hi LN2 Press
1kW 1 full(half) stkl 55 011 003 10 LN2 press
1kW 1 full (halt) stkl 55 557 02
~ 1 Equal percentage (log) plugs
)
-~
A2-4
I middot bull
tA JL(Q)adisect9 Valive sectflzllimg
CRYOSTAT GAS MAKEUPIRETURN 1
LOADS Max Min Remarks
asINLET3 40kW 1kW Range 40(6) 1 full(halt) stk2
LAr(gs) 250 625 (scth) 195k 049k
Cv 255 064
--asOUTLET3 5kW 1kW Range 5 1
) LAr(gs) 313 625 (scth) 24k 049k
Cv 32 064
-~
Notes 1a Makeup(cooldown) = Reverse acting b Retum( operate) = Direct acting
2 Equal percentage (log) plugs 3 This is one valve take more severe Inlet service requirements
)
A2-S
~FL~O~W~S~I~ZI~N~G~C~R~Y~O=S~Y~ST~E~M~V~A~L~V~E~S~_____________________7
Cryostat Loop Outlet Valve
The outlet valve vents the gaseous nitrogen to atmosphere and has a pressure drop of 30 psi It must be able to accommodate a flow range from the nominal value of the operating loops 546 gls (5573 scfh) to the maximum value of the cooldown loops 2184 gls (22292 scfh) By using form ula (IO the range of flow coefficients can be calculated It is found that CVm in=020 and Cvmax=80 (40 1) and the equal percentage plug 12 stroke solution will be applied
Cryostat Gas MakeupReturn Valve The cryostats and the LAr source dewar gas spaces communicate
through a valve that supplies makeup gas to the cryostat on cooldown and condensing and returns gas to the dewar on warmup or above some set pressure during normal operation
The expected makeup and return pressure differences are taken as 5psid the maximum flow the condenser flow to the cryostats is 250 gIs and the minimum flow return under nominal conditions is 625 gs The calculated Cvmax =255 and the Cvm in=064 (401) will require the equal percentage and 112 stroke option
) CONCLUSION
The small Cv values calculated and the large turndown ratios of the valves make the valve and plug selection process difficult The large range of necessary Cv values can be accomplished however by using equal percentage plugs Limiting the stroke of the valves to 50 by controlling the drive signals to 4-12ma (rather than 4-20ma) will allow for closer control of the very low operating flows through increased loop gain This combination of techniques should adequately cover the requirements as described
7
DFL~O~W~SuI~ZI~N~G~C~R~Y~O~S~Y~ST~EwM~VuA~L~VLE~S~_____________________8
--
Appendix I
Control valye Liauid Quality
The inlet liquid enthalpy is related to exit liquid and gas enthalpyies as
where HoPo the inlet sat liquid enthalpy HI P I = the exit liquid enthalpy HgPl = the exit vapor enthalpy
Q = liquid quality = (I-x) x vapor fraction
For the Operating loop-inlet Po 35 atm PI 30 atm
J x = (-95175 98938)(98938 + 84169) 002
see enthalpy vs pressure curve figure 1
The corresponding Cy 1) is only 14 of the that calculated in this report 2) affects only the upper flow limit 3) and will be considered by selecting Cy values 10 to 20 larger than calculated for liquid flow This general conclusion applies to all the applications considered here
Note too that subcooling by 05 atm or more prevents the formation of vapor in this case A gt1 atm subcooler will be considered for the critical cryostat feed manifold application see figure 2
8
LFL~OpoundW~SulkZIuNllG~C~R~Y~O~S~Y~STLE~M~VuA~L~VLE~S~_____________________9
Appendix II
Figures
1 Saturated LN2 Enthalpy 2 Liquid Quality Control
Supporting Graphs and Tabulations
1 Approximate Cv as a function of nominal valve size
2a Valve responses for i quick opening 11 linear ill equal percentage (log)
- titi half stroke equal percentage
J 2b Log plot of
1 2a iii 11 2a iiii
3 Valve sizing Liquid Argon Dewar
4 Valve sizing Cryostat cooling Loops
5 Valve sizing Cryostat gas makeupreturn
9
Saturated LN2 Enthalpy
-80
-90
t)J) 01 -100 - ~
=shy-CS- =
j ~ -110
-120
~ V
V V
~V j V
lI J
V
I
-130
o 1 2 3 4 5 6
Pressure Atm
-~ F-l
)
The sum of the heat leaks to the supply manifold is 1OOW The sub-cooling provided by the source and cooling loop elevation differences is just equal to 100W at a manifold flow of 37 gls Above that flow the liquid quality is 100 GN2 venting or suplimentary subcoolshying is required for smaller flows The calculated steady state manifold flow requirement is 165 gIs requiring a ventlsubcooling flow of 0275 gls (0005gpm)
)
F-2
CV data 5
4
3
2
o 00
I
I
I
~
V~
01 02 03 04 05 06
Diameter in
J
CV data 35
30
25
~ 20Q =rJl 15
U 10
5
0
J
I J
)
~
V ~
lshy00 02 04 06 08 10 12 14 16
I
Diameter in A2-1
-------~--
Valve Responses 100
80
~
= 600 til
-=-0
40 ~ gt= 20
o
I ~ o--7 ~ - V
J 1111 IL
I ~ v V
I ~ lV
~ III ~
V
I l
V II
1 1V
~ V
lV
1 ~V J
o 10 20 30 40 50 60 70 80 90 100
Flow
) A2-2a
Equal Pct (log) Plug
100
90
80
~ 70
= 600til 50 0
=- 40
~ 30-gt= 20
10
I
V J
1
V ~ ~
Vmiddot
l
II
I II
r
I
1
101
Flow
viol
I r
i
--
lL(Q)Sldisect9 VSllive Sizmg
ARGON DEWAR LN2 CONDENSER
LOADS
INLET Nom Range LN2(gs)
(gpm) Cv
)
OUTLET Nom Range GN2(gs)
(sctb) Cv
Notes
Max Min 40kW
100(14) 205 6 054 08
100(14) 205 209k 105 167
410W
1 21 004 0005 0008
1 21 206 010 016
1 Equal percentage (log) plugs
)
Remarks Condensing Steady State
full(hali) stkl
10 LN2 press hi LN2 press
full(half) stkl
10 LN2 press hi LN2 press
~-3
CRYOSTAT COOLING LOOPS
LOADS
CD INLET Range LN2(gs)
(gpm) Cv
OPINLET-) Range
LN2(gs) (gpm)
Cv
OUTLET Range LN2(gs)
(scfh) Cv
Notes
Max
40kW 4 218 433 122
10kW 10(5) 55 108 03
40kW 40(6) 218 22k 80
Min Remarks
10kW 1 linear plug 55 108 03 hi LN2 Press
1kW 1 full(half) stkl 55 011 003 10 LN2 press
1kW 1 full (halt) stkl 55 557 02
~ 1 Equal percentage (log) plugs
)
-~
A2-4
I middot bull
tA JL(Q)adisect9 Valive sectflzllimg
CRYOSTAT GAS MAKEUPIRETURN 1
LOADS Max Min Remarks
asINLET3 40kW 1kW Range 40(6) 1 full(halt) stk2
LAr(gs) 250 625 (scth) 195k 049k
Cv 255 064
--asOUTLET3 5kW 1kW Range 5 1
) LAr(gs) 313 625 (scth) 24k 049k
Cv 32 064
-~
Notes 1a Makeup(cooldown) = Reverse acting b Retum( operate) = Direct acting
2 Equal percentage (log) plugs 3 This is one valve take more severe Inlet service requirements
)
A2-S
DFL~O~W~SuI~ZI~N~G~C~R~Y~O~S~Y~ST~EwM~VuA~L~VLE~S~_____________________8
--
Appendix I
Control valye Liauid Quality
The inlet liquid enthalpy is related to exit liquid and gas enthalpyies as
where HoPo the inlet sat liquid enthalpy HI P I = the exit liquid enthalpy HgPl = the exit vapor enthalpy
Q = liquid quality = (I-x) x vapor fraction
For the Operating loop-inlet Po 35 atm PI 30 atm
J x = (-95175 98938)(98938 + 84169) 002
see enthalpy vs pressure curve figure 1
The corresponding Cy 1) is only 14 of the that calculated in this report 2) affects only the upper flow limit 3) and will be considered by selecting Cy values 10 to 20 larger than calculated for liquid flow This general conclusion applies to all the applications considered here
Note too that subcooling by 05 atm or more prevents the formation of vapor in this case A gt1 atm subcooler will be considered for the critical cryostat feed manifold application see figure 2
8
LFL~OpoundW~SulkZIuNllG~C~R~Y~O~S~Y~STLE~M~VuA~L~VLE~S~_____________________9
Appendix II
Figures
1 Saturated LN2 Enthalpy 2 Liquid Quality Control
Supporting Graphs and Tabulations
1 Approximate Cv as a function of nominal valve size
2a Valve responses for i quick opening 11 linear ill equal percentage (log)
- titi half stroke equal percentage
J 2b Log plot of
1 2a iii 11 2a iiii
3 Valve sizing Liquid Argon Dewar
4 Valve sizing Cryostat cooling Loops
5 Valve sizing Cryostat gas makeupreturn
9
Saturated LN2 Enthalpy
-80
-90
t)J) 01 -100 - ~
=shy-CS- =
j ~ -110
-120
~ V
V V
~V j V
lI J
V
I
-130
o 1 2 3 4 5 6
Pressure Atm
-~ F-l
)
The sum of the heat leaks to the supply manifold is 1OOW The sub-cooling provided by the source and cooling loop elevation differences is just equal to 100W at a manifold flow of 37 gls Above that flow the liquid quality is 100 GN2 venting or suplimentary subcoolshying is required for smaller flows The calculated steady state manifold flow requirement is 165 gIs requiring a ventlsubcooling flow of 0275 gls (0005gpm)
)
F-2
CV data 5
4
3
2
o 00
I
I
I
~
V~
01 02 03 04 05 06
Diameter in
J
CV data 35
30
25
~ 20Q =rJl 15
U 10
5
0
J
I J
)
~
V ~
lshy00 02 04 06 08 10 12 14 16
I
Diameter in A2-1
-------~--
Valve Responses 100
80
~
= 600 til
-=-0
40 ~ gt= 20
o
I ~ o--7 ~ - V
J 1111 IL
I ~ v V
I ~ lV
~ III ~
V
I l
V II
1 1V
~ V
lV
1 ~V J
o 10 20 30 40 50 60 70 80 90 100
Flow
) A2-2a
Equal Pct (log) Plug
100
90
80
~ 70
= 600til 50 0
=- 40
~ 30-gt= 20
10
I
V J
1
V ~ ~
Vmiddot
l
II
I II
r
I
1
101
Flow
viol
I r
i
--
lL(Q)Sldisect9 VSllive Sizmg
ARGON DEWAR LN2 CONDENSER
LOADS
INLET Nom Range LN2(gs)
(gpm) Cv
)
OUTLET Nom Range GN2(gs)
(sctb) Cv
Notes
Max Min 40kW
100(14) 205 6 054 08
100(14) 205 209k 105 167
410W
1 21 004 0005 0008
1 21 206 010 016
1 Equal percentage (log) plugs
)
Remarks Condensing Steady State
full(hali) stkl
10 LN2 press hi LN2 press
full(half) stkl
10 LN2 press hi LN2 press
~-3
CRYOSTAT COOLING LOOPS
LOADS
CD INLET Range LN2(gs)
(gpm) Cv
OPINLET-) Range
LN2(gs) (gpm)
Cv
OUTLET Range LN2(gs)
(scfh) Cv
Notes
Max
40kW 4 218 433 122
10kW 10(5) 55 108 03
40kW 40(6) 218 22k 80
Min Remarks
10kW 1 linear plug 55 108 03 hi LN2 Press
1kW 1 full(half) stkl 55 011 003 10 LN2 press
1kW 1 full (halt) stkl 55 557 02
~ 1 Equal percentage (log) plugs
)
-~
A2-4
I middot bull
tA JL(Q)adisect9 Valive sectflzllimg
CRYOSTAT GAS MAKEUPIRETURN 1
LOADS Max Min Remarks
asINLET3 40kW 1kW Range 40(6) 1 full(halt) stk2
LAr(gs) 250 625 (scth) 195k 049k
Cv 255 064
--asOUTLET3 5kW 1kW Range 5 1
) LAr(gs) 313 625 (scth) 24k 049k
Cv 32 064
-~
Notes 1a Makeup(cooldown) = Reverse acting b Retum( operate) = Direct acting
2 Equal percentage (log) plugs 3 This is one valve take more severe Inlet service requirements
)
A2-S
LFL~OpoundW~SulkZIuNllG~C~R~Y~O~S~Y~STLE~M~VuA~L~VLE~S~_____________________9
Appendix II
Figures
1 Saturated LN2 Enthalpy 2 Liquid Quality Control
Supporting Graphs and Tabulations
1 Approximate Cv as a function of nominal valve size
2a Valve responses for i quick opening 11 linear ill equal percentage (log)
- titi half stroke equal percentage
J 2b Log plot of
1 2a iii 11 2a iiii
3 Valve sizing Liquid Argon Dewar
4 Valve sizing Cryostat cooling Loops
5 Valve sizing Cryostat gas makeupreturn
9
Saturated LN2 Enthalpy
-80
-90
t)J) 01 -100 - ~
=shy-CS- =
j ~ -110
-120
~ V
V V
~V j V
lI J
V
I
-130
o 1 2 3 4 5 6
Pressure Atm
-~ F-l
)
The sum of the heat leaks to the supply manifold is 1OOW The sub-cooling provided by the source and cooling loop elevation differences is just equal to 100W at a manifold flow of 37 gls Above that flow the liquid quality is 100 GN2 venting or suplimentary subcoolshying is required for smaller flows The calculated steady state manifold flow requirement is 165 gIs requiring a ventlsubcooling flow of 0275 gls (0005gpm)
)
F-2
CV data 5
4
3
2
o 00
I
I
I
~
V~
01 02 03 04 05 06
Diameter in
J
CV data 35
30
25
~ 20Q =rJl 15
U 10
5
0
J
I J
)
~
V ~
lshy00 02 04 06 08 10 12 14 16
I
Diameter in A2-1
-------~--
Valve Responses 100
80
~
= 600 til
-=-0
40 ~ gt= 20
o
I ~ o--7 ~ - V
J 1111 IL
I ~ v V
I ~ lV
~ III ~
V
I l
V II
1 1V
~ V
lV
1 ~V J
o 10 20 30 40 50 60 70 80 90 100
Flow
) A2-2a
Equal Pct (log) Plug
100
90
80
~ 70
= 600til 50 0
=- 40
~ 30-gt= 20
10
I
V J
1
V ~ ~
Vmiddot
l
II
I II
r
I
1
101
Flow
viol
I r
i
--
lL(Q)Sldisect9 VSllive Sizmg
ARGON DEWAR LN2 CONDENSER
LOADS
INLET Nom Range LN2(gs)
(gpm) Cv
)
OUTLET Nom Range GN2(gs)
(sctb) Cv
Notes
Max Min 40kW
100(14) 205 6 054 08
100(14) 205 209k 105 167
410W
1 21 004 0005 0008
1 21 206 010 016
1 Equal percentage (log) plugs
)
Remarks Condensing Steady State
full(hali) stkl
10 LN2 press hi LN2 press
full(half) stkl
10 LN2 press hi LN2 press
~-3
CRYOSTAT COOLING LOOPS
LOADS
CD INLET Range LN2(gs)
(gpm) Cv
OPINLET-) Range
LN2(gs) (gpm)
Cv
OUTLET Range LN2(gs)
(scfh) Cv
Notes
Max
40kW 4 218 433 122
10kW 10(5) 55 108 03
40kW 40(6) 218 22k 80
Min Remarks
10kW 1 linear plug 55 108 03 hi LN2 Press
1kW 1 full(half) stkl 55 011 003 10 LN2 press
1kW 1 full (halt) stkl 55 557 02
~ 1 Equal percentage (log) plugs
)
-~
A2-4
I middot bull
tA JL(Q)adisect9 Valive sectflzllimg
CRYOSTAT GAS MAKEUPIRETURN 1
LOADS Max Min Remarks
asINLET3 40kW 1kW Range 40(6) 1 full(halt) stk2
LAr(gs) 250 625 (scth) 195k 049k
Cv 255 064
--asOUTLET3 5kW 1kW Range 5 1
) LAr(gs) 313 625 (scth) 24k 049k
Cv 32 064
-~
Notes 1a Makeup(cooldown) = Reverse acting b Retum( operate) = Direct acting
2 Equal percentage (log) plugs 3 This is one valve take more severe Inlet service requirements
)
A2-S
Saturated LN2 Enthalpy
-80
-90
t)J) 01 -100 - ~
=shy-CS- =
j ~ -110
-120
~ V
V V
~V j V
lI J
V
I
-130
o 1 2 3 4 5 6
Pressure Atm
-~ F-l
)
The sum of the heat leaks to the supply manifold is 1OOW The sub-cooling provided by the source and cooling loop elevation differences is just equal to 100W at a manifold flow of 37 gls Above that flow the liquid quality is 100 GN2 venting or suplimentary subcoolshying is required for smaller flows The calculated steady state manifold flow requirement is 165 gIs requiring a ventlsubcooling flow of 0275 gls (0005gpm)
)
F-2
CV data 5
4
3
2
o 00
I
I
I
~
V~
01 02 03 04 05 06
Diameter in
J
CV data 35
30
25
~ 20Q =rJl 15
U 10
5
0
J
I J
)
~
V ~
lshy00 02 04 06 08 10 12 14 16
I
Diameter in A2-1
-------~--
Valve Responses 100
80
~
= 600 til
-=-0
40 ~ gt= 20
o
I ~ o--7 ~ - V
J 1111 IL
I ~ v V
I ~ lV
~ III ~
V
I l
V II
1 1V
~ V
lV
1 ~V J
o 10 20 30 40 50 60 70 80 90 100
Flow
) A2-2a
Equal Pct (log) Plug
100
90
80
~ 70
= 600til 50 0
=- 40
~ 30-gt= 20
10
I
V J
1
V ~ ~
Vmiddot
l
II
I II
r
I
1
101
Flow
viol
I r
i
--
lL(Q)Sldisect9 VSllive Sizmg
ARGON DEWAR LN2 CONDENSER
LOADS
INLET Nom Range LN2(gs)
(gpm) Cv
)
OUTLET Nom Range GN2(gs)
(sctb) Cv
Notes
Max Min 40kW
100(14) 205 6 054 08
100(14) 205 209k 105 167
410W
1 21 004 0005 0008
1 21 206 010 016
1 Equal percentage (log) plugs
)
Remarks Condensing Steady State
full(hali) stkl
10 LN2 press hi LN2 press
full(half) stkl
10 LN2 press hi LN2 press
~-3
CRYOSTAT COOLING LOOPS
LOADS
CD INLET Range LN2(gs)
(gpm) Cv
OPINLET-) Range
LN2(gs) (gpm)
Cv
OUTLET Range LN2(gs)
(scfh) Cv
Notes
Max
40kW 4 218 433 122
10kW 10(5) 55 108 03
40kW 40(6) 218 22k 80
Min Remarks
10kW 1 linear plug 55 108 03 hi LN2 Press
1kW 1 full(half) stkl 55 011 003 10 LN2 press
1kW 1 full (halt) stkl 55 557 02
~ 1 Equal percentage (log) plugs
)
-~
A2-4
I middot bull
tA JL(Q)adisect9 Valive sectflzllimg
CRYOSTAT GAS MAKEUPIRETURN 1
LOADS Max Min Remarks
asINLET3 40kW 1kW Range 40(6) 1 full(halt) stk2
LAr(gs) 250 625 (scth) 195k 049k
Cv 255 064
--asOUTLET3 5kW 1kW Range 5 1
) LAr(gs) 313 625 (scth) 24k 049k
Cv 32 064
-~
Notes 1a Makeup(cooldown) = Reverse acting b Retum( operate) = Direct acting
2 Equal percentage (log) plugs 3 This is one valve take more severe Inlet service requirements
)
A2-S
)
The sum of the heat leaks to the supply manifold is 1OOW The sub-cooling provided by the source and cooling loop elevation differences is just equal to 100W at a manifold flow of 37 gls Above that flow the liquid quality is 100 GN2 venting or suplimentary subcoolshying is required for smaller flows The calculated steady state manifold flow requirement is 165 gIs requiring a ventlsubcooling flow of 0275 gls (0005gpm)
)
F-2
CV data 5
4
3
2
o 00
I
I
I
~
V~
01 02 03 04 05 06
Diameter in
J
CV data 35
30
25
~ 20Q =rJl 15
U 10
5
0
J
I J
)
~
V ~
lshy00 02 04 06 08 10 12 14 16
I
Diameter in A2-1
-------~--
Valve Responses 100
80
~
= 600 til
-=-0
40 ~ gt= 20
o
I ~ o--7 ~ - V
J 1111 IL
I ~ v V
I ~ lV
~ III ~
V
I l
V II
1 1V
~ V
lV
1 ~V J
o 10 20 30 40 50 60 70 80 90 100
Flow
) A2-2a
Equal Pct (log) Plug
100
90
80
~ 70
= 600til 50 0
=- 40
~ 30-gt= 20
10
I
V J
1
V ~ ~
Vmiddot
l
II
I II
r
I
1
101
Flow
viol
I r
i
--
lL(Q)Sldisect9 VSllive Sizmg
ARGON DEWAR LN2 CONDENSER
LOADS
INLET Nom Range LN2(gs)
(gpm) Cv
)
OUTLET Nom Range GN2(gs)
(sctb) Cv
Notes
Max Min 40kW
100(14) 205 6 054 08
100(14) 205 209k 105 167
410W
1 21 004 0005 0008
1 21 206 010 016
1 Equal percentage (log) plugs
)
Remarks Condensing Steady State
full(hali) stkl
10 LN2 press hi LN2 press
full(half) stkl
10 LN2 press hi LN2 press
~-3
CRYOSTAT COOLING LOOPS
LOADS
CD INLET Range LN2(gs)
(gpm) Cv
OPINLET-) Range
LN2(gs) (gpm)
Cv
OUTLET Range LN2(gs)
(scfh) Cv
Notes
Max
40kW 4 218 433 122
10kW 10(5) 55 108 03
40kW 40(6) 218 22k 80
Min Remarks
10kW 1 linear plug 55 108 03 hi LN2 Press
1kW 1 full(half) stkl 55 011 003 10 LN2 press
1kW 1 full (halt) stkl 55 557 02
~ 1 Equal percentage (log) plugs
)
-~
A2-4
I middot bull
tA JL(Q)adisect9 Valive sectflzllimg
CRYOSTAT GAS MAKEUPIRETURN 1
LOADS Max Min Remarks
asINLET3 40kW 1kW Range 40(6) 1 full(halt) stk2
LAr(gs) 250 625 (scth) 195k 049k
Cv 255 064
--asOUTLET3 5kW 1kW Range 5 1
) LAr(gs) 313 625 (scth) 24k 049k
Cv 32 064
-~
Notes 1a Makeup(cooldown) = Reverse acting b Retum( operate) = Direct acting
2 Equal percentage (log) plugs 3 This is one valve take more severe Inlet service requirements
)
A2-S
CV data 5
4
3
2
o 00
I
I
I
~
V~
01 02 03 04 05 06
Diameter in
J
CV data 35
30
25
~ 20Q =rJl 15
U 10
5
0
J
I J
)
~
V ~
lshy00 02 04 06 08 10 12 14 16
I
Diameter in A2-1
-------~--
Valve Responses 100
80
~
= 600 til
-=-0
40 ~ gt= 20
o
I ~ o--7 ~ - V
J 1111 IL
I ~ v V
I ~ lV
~ III ~
V
I l
V II
1 1V
~ V
lV
1 ~V J
o 10 20 30 40 50 60 70 80 90 100
Flow
) A2-2a
Equal Pct (log) Plug
100
90
80
~ 70
= 600til 50 0
=- 40
~ 30-gt= 20
10
I
V J
1
V ~ ~
Vmiddot
l
II
I II
r
I
1
101
Flow
viol
I r
i
--
lL(Q)Sldisect9 VSllive Sizmg
ARGON DEWAR LN2 CONDENSER
LOADS
INLET Nom Range LN2(gs)
(gpm) Cv
)
OUTLET Nom Range GN2(gs)
(sctb) Cv
Notes
Max Min 40kW
100(14) 205 6 054 08
100(14) 205 209k 105 167
410W
1 21 004 0005 0008
1 21 206 010 016
1 Equal percentage (log) plugs
)
Remarks Condensing Steady State
full(hali) stkl
10 LN2 press hi LN2 press
full(half) stkl
10 LN2 press hi LN2 press
~-3
CRYOSTAT COOLING LOOPS
LOADS
CD INLET Range LN2(gs)
(gpm) Cv
OPINLET-) Range
LN2(gs) (gpm)
Cv
OUTLET Range LN2(gs)
(scfh) Cv
Notes
Max
40kW 4 218 433 122
10kW 10(5) 55 108 03
40kW 40(6) 218 22k 80
Min Remarks
10kW 1 linear plug 55 108 03 hi LN2 Press
1kW 1 full(half) stkl 55 011 003 10 LN2 press
1kW 1 full (halt) stkl 55 557 02
~ 1 Equal percentage (log) plugs
)
-~
A2-4
I middot bull
tA JL(Q)adisect9 Valive sectflzllimg
CRYOSTAT GAS MAKEUPIRETURN 1
LOADS Max Min Remarks
asINLET3 40kW 1kW Range 40(6) 1 full(halt) stk2
LAr(gs) 250 625 (scth) 195k 049k
Cv 255 064
--asOUTLET3 5kW 1kW Range 5 1
) LAr(gs) 313 625 (scth) 24k 049k
Cv 32 064
-~
Notes 1a Makeup(cooldown) = Reverse acting b Retum( operate) = Direct acting
2 Equal percentage (log) plugs 3 This is one valve take more severe Inlet service requirements
)
A2-S
Valve Responses 100
80
~
= 600 til
-=-0
40 ~ gt= 20
o
I ~ o--7 ~ - V
J 1111 IL
I ~ v V
I ~ lV
~ III ~
V
I l
V II
1 1V
~ V
lV
1 ~V J
o 10 20 30 40 50 60 70 80 90 100
Flow
) A2-2a
Equal Pct (log) Plug
100
90
80
~ 70
= 600til 50 0
=- 40
~ 30-gt= 20
10
I
V J
1
V ~ ~
Vmiddot
l
II
I II
r
I
1
101
Flow
viol
I r
i
--
lL(Q)Sldisect9 VSllive Sizmg
ARGON DEWAR LN2 CONDENSER
LOADS
INLET Nom Range LN2(gs)
(gpm) Cv
)
OUTLET Nom Range GN2(gs)
(sctb) Cv
Notes
Max Min 40kW
100(14) 205 6 054 08
100(14) 205 209k 105 167
410W
1 21 004 0005 0008
1 21 206 010 016
1 Equal percentage (log) plugs
)
Remarks Condensing Steady State
full(hali) stkl
10 LN2 press hi LN2 press
full(half) stkl
10 LN2 press hi LN2 press
~-3
CRYOSTAT COOLING LOOPS
LOADS
CD INLET Range LN2(gs)
(gpm) Cv
OPINLET-) Range
LN2(gs) (gpm)
Cv
OUTLET Range LN2(gs)
(scfh) Cv
Notes
Max
40kW 4 218 433 122
10kW 10(5) 55 108 03
40kW 40(6) 218 22k 80
Min Remarks
10kW 1 linear plug 55 108 03 hi LN2 Press
1kW 1 full(half) stkl 55 011 003 10 LN2 press
1kW 1 full (halt) stkl 55 557 02
~ 1 Equal percentage (log) plugs
)
-~
A2-4
I middot bull
tA JL(Q)adisect9 Valive sectflzllimg
CRYOSTAT GAS MAKEUPIRETURN 1
LOADS Max Min Remarks
asINLET3 40kW 1kW Range 40(6) 1 full(halt) stk2
LAr(gs) 250 625 (scth) 195k 049k
Cv 255 064
--asOUTLET3 5kW 1kW Range 5 1
) LAr(gs) 313 625 (scth) 24k 049k
Cv 32 064
-~
Notes 1a Makeup(cooldown) = Reverse acting b Retum( operate) = Direct acting
2 Equal percentage (log) plugs 3 This is one valve take more severe Inlet service requirements
)
A2-S
--
lL(Q)Sldisect9 VSllive Sizmg
ARGON DEWAR LN2 CONDENSER
LOADS
INLET Nom Range LN2(gs)
(gpm) Cv
)
OUTLET Nom Range GN2(gs)
(sctb) Cv
Notes
Max Min 40kW
100(14) 205 6 054 08
100(14) 205 209k 105 167
410W
1 21 004 0005 0008
1 21 206 010 016
1 Equal percentage (log) plugs
)
Remarks Condensing Steady State
full(hali) stkl
10 LN2 press hi LN2 press
full(half) stkl
10 LN2 press hi LN2 press
~-3
CRYOSTAT COOLING LOOPS
LOADS
CD INLET Range LN2(gs)
(gpm) Cv
OPINLET-) Range
LN2(gs) (gpm)
Cv
OUTLET Range LN2(gs)
(scfh) Cv
Notes
Max
40kW 4 218 433 122
10kW 10(5) 55 108 03
40kW 40(6) 218 22k 80
Min Remarks
10kW 1 linear plug 55 108 03 hi LN2 Press
1kW 1 full(half) stkl 55 011 003 10 LN2 press
1kW 1 full (halt) stkl 55 557 02
~ 1 Equal percentage (log) plugs
)
-~
A2-4
I middot bull
tA JL(Q)adisect9 Valive sectflzllimg
CRYOSTAT GAS MAKEUPIRETURN 1
LOADS Max Min Remarks
asINLET3 40kW 1kW Range 40(6) 1 full(halt) stk2
LAr(gs) 250 625 (scth) 195k 049k
Cv 255 064
--asOUTLET3 5kW 1kW Range 5 1
) LAr(gs) 313 625 (scth) 24k 049k
Cv 32 064
-~
Notes 1a Makeup(cooldown) = Reverse acting b Retum( operate) = Direct acting
2 Equal percentage (log) plugs 3 This is one valve take more severe Inlet service requirements
)
A2-S
CRYOSTAT COOLING LOOPS
LOADS
CD INLET Range LN2(gs)
(gpm) Cv
OPINLET-) Range
LN2(gs) (gpm)
Cv
OUTLET Range LN2(gs)
(scfh) Cv
Notes
Max
40kW 4 218 433 122
10kW 10(5) 55 108 03
40kW 40(6) 218 22k 80
Min Remarks
10kW 1 linear plug 55 108 03 hi LN2 Press
1kW 1 full(half) stkl 55 011 003 10 LN2 press
1kW 1 full (halt) stkl 55 557 02
~ 1 Equal percentage (log) plugs
)
-~
A2-4
I middot bull
tA JL(Q)adisect9 Valive sectflzllimg
CRYOSTAT GAS MAKEUPIRETURN 1
LOADS Max Min Remarks
asINLET3 40kW 1kW Range 40(6) 1 full(halt) stk2
LAr(gs) 250 625 (scth) 195k 049k
Cv 255 064
--asOUTLET3 5kW 1kW Range 5 1
) LAr(gs) 313 625 (scth) 24k 049k
Cv 32 064
-~
Notes 1a Makeup(cooldown) = Reverse acting b Retum( operate) = Direct acting
2 Equal percentage (log) plugs 3 This is one valve take more severe Inlet service requirements
)
A2-S
I middot bull
tA JL(Q)adisect9 Valive sectflzllimg
CRYOSTAT GAS MAKEUPIRETURN 1
LOADS Max Min Remarks
asINLET3 40kW 1kW Range 40(6) 1 full(halt) stk2
LAr(gs) 250 625 (scth) 195k 049k
Cv 255 064
--asOUTLET3 5kW 1kW Range 5 1
) LAr(gs) 313 625 (scth) 24k 049k
Cv 32 064
-~
Notes 1a Makeup(cooldown) = Reverse acting b Retum( operate) = Direct acting
2 Equal percentage (log) plugs 3 This is one valve take more severe Inlet service requirements
)
A2-S
