orifice DP Sizing with Beta
Current Flange Spec Sheet_MonelITEMREV.QTY.TAG. NO.PIPE SIZE
(IN.)SCH.ORIFICE (IN.)FLOW QUANTITY (SCFH)UPSTREAM PRESSURE
(PSIG)DP (PSI)MWSGTEMP. (F)FLANGE
RATINGSERVICE12120FO-0572800.0842506057a17.00100300Pilot gas to
acid relief header.23456789101. The actual flow of 20FO-057 is
about 110 SCFH for a bore diameter of 0.084.
&L&"Arial Narrow,Regular"&10&P of
&N&R&9&F/&AINSTRUMENT SPECIFICATIONCitgo
Petroleum Corporation135th Street & New AvenueLemont, IL
60439Flange-type Restrictive OrificesALL ITEMS SHALL COMPLY WITH
GENERAL SPECIFICATION SHEETSMATERIAL: MonelInstallation notes:1.
Orifice dia. As specified to suit required conditions.2. Gaskets
furnished by vendor.
Current Union Spec SheetITEMREV.QTY.TAG. NO.PIPE SIZE
(IN.)SCH.ORIFICE (IN.)FLOW QUANTITY (SCFH)UPSTREAM PRESSURE
(PSIG)DP (PSI)MWSGTEMP. (F)FLANGE
RATINGSERVICE11120FO-1841-1/2800.2856057a0.5861003000Acid pump vent
header purge.23456789101. Item 1 is made of monel.
&L&"Arial Narrow,Regular"&10&P of
&N&R&9&F/&AINSTRUMENT SPECIFICATIONCitgo
Petroleum Corporation135th Street & New AvenueLemont, IL
60439Union Restrictive OrificesALL ITEMS SHALL COMPLY WITH GENERAL
SPECIFICATION SHEETSMATERIAL: 316SSInstallation notes:1. Unless
otherwise specified, the only markings on the orifice tab shall be
the orfice diameter indicated by a decimal fraction as shown on the
drawing with 1/16-in. figure stamping hand dies.2. Where lines are
to be insulated, the insulated material covering the union shall be
applied in such a manner that the markings on the tab will be fully
exposed.3. No asbestos-bearing material is acceptable; vendor to
provide TFE gaskets.
Current Flange Spec Sh_SSITEMREV.QTY.TAG. NO.PIPE SIZE
(IN.)SCH.ORIFICE (IN.)FLOW QUANTITY (SCFH)UPSTREAM PRESSURE
(PSIG)DP (PSI)MWSGTEMP. (F)FLANGE
RATINGSERVICE11120FO-1752800.1356055a17.00100150Pilot gas to
20F-527.2345678910
&L&"Arial Narrow,Regular"&10&P of
&N&R&9&F/&AINSTRUMENT SPECIFICATIONCitgo
Petroleum Corporation135th Street & New AvenueLemont, IL
60439Flange-type Restrictive OrificesALL ITEMS SHALL COMPLY WITH
GENERAL SPECIFICATION SHEETSMATERIAL: 316SSInstallation notes:1.
Orifice dia. As specified to suit required conditions.2. Gaskets
furnished by vendor.
New Union Spec SheetITEMREV.QTY.TAG. NO.PIPE SIZE
(IN.)SCH.ORIFICE (IN.)FLOW QUANTITY (SCFH)UPSTREAM PRESSURE
(PSIG)DP (PSI)MWSGTEMP. (F)FLANGE
RATINGSERVICE111280a1002345678910
&L&"Arial Narrow,Regular"&10&P of
&N&R&9&F/&AINSTRUMENT SPECIFICATIONCitgo
Petroleum Corporation135th Street & New AvenueLemont, IL
60439Union Restrictive OrificesALL ITEMS SHALL COMPLY WITH GENERAL
SPECIFICATION SHEETSMATERIAL: 316SSInstallation notes:1. Unless
otherwise specified, the only markings on the orifice tab shall be
the orfice diameter indicated by a decimal fraction as shown on the
drawing with 1/16-in. figure stamping hand dies.2. Where lines are
to be insulated, the insulated material covering the union shall be
applied in such a manner that the markings on the tab will be fully
exposed.3. No asbestos-bearing material is acceptable; vendor to
provide TFE gaskets.
InstructionsYellow is an input cell:Green is a
calculation:P1:60psigW =11.12PPHUnderline is value actually
used:Green in grey is a look-up value:0.603tp =2.500.607White in
black is a final answer:D2 =0.106in.Important reference information
about a cell is in violet:From Fluor tableCell for iteration with
goal seek:Target (To) cell for goal seek:Changing cell for goal
seek:[1st Cell][2nd Cell][3rd Cell]4.874.930.084
Sheet3No.DATEREVISIONSHEET NO.REV.NOMINAL LINE SIZE
IN.SPNOMONELANSI 150LBANSI 300LBANSI 600LBISSUE
DATE:1/2102321.5485454DIMENSIONS IN
MMMANUFACTURER:3/8102321.55767671102321.5677373P.O. No.:1
1/2102322.08695952102322.5105111111ISSUED:CHECK:3102323.01371491494102323.01751811946121323.02222512678121326.027930832110140456.034036240012140456.041042245714
OD140459.045148649216 OD152459.051454056518 OD1525112.054959761320
OD1525112.060365167924
OD1525116.07147717871/241-1/41/161-7/82-1/82-1/8DIMENSIONS IN
INCHES3/441-1/41/162-1/42-5/82-5/8141-1/41/162-5/82-7/82-7/81
1/241-1/45/643-3/83-3/43-3/4241-1/43/324-1/84-3/84-3/8341-1/21/85-3/85-7/85-7/8441-1/21/86-7/87-1/87-5/864-3/81-1/21/88-3/49-7/810-1/284-3/41-1/21/41112-1/812-5/8105-1/21-3/41/413-3/814-1/415-3/4125-1/21-3/41/416-1/816-5/81814
OD5-1/21-3/43/817-3/419-1/819-3/816 OD61-3/43/820-1/421-1/422-1/418
OD621/221-5/823-1/224-1/820 OD621/223-7/825-3/426-7/824
OD625/828-1/430-1/231-1/8NOMINAL LINE SIZE IN.SPNO316SSANSI
150LBANSI 300LBANSI 600LB1/2102321.5485454DIMENSIONS IN
MM3/8102321.55767671102321.56773731
1/2102322.08695952102322.51051111113102323.01371491494102323.01751811946121323.02222512678121326.027930832110140456.034036240012140456.041042245714
OD140459.045148649216 OD152459.051454056518 OD1525112.054959761320
OD1525112.060365167924
OD1525116.07147717871/241-1/41/161-7/82-1/82-1/8DIMENSIONS IN
INCHES3/441-1/41/162-1/42-5/82-5/8141-1/41/162-5/82-7/82-7/81
1/241-1/45/643-3/83-3/43-3/4241-1/43/324-1/84-3/84-3/8341-1/21/85-3/85-7/85-7/8441-1/21/86-7/87-1/87-5/864-3/81-1/21/88-3/49-7/810-1/284-3/41-1/21/41112-1/812-5/8105-1/21-3/41/413-3/814-1/415-3/4125-1/21-3/41/416-1/816-5/81814
OD5-1/21-3/43/817-3/419-1/819-3/816 OD61-3/43/820-1/421-1/422-1/418
OD621/221-5/823-1/224-1/820 OD621/223-3/425-5/826-3/424
OD625/828-1/430-3/831
New Flange Spec Sheet_SSITEMREV.QTY.TAG. NO.PIPE SIZE
(IN.)SCH.ORIFICE (IN.)FLOW QUANTITY (SCFH)UPSTREAM PRESSURE
(PSIG)DP (PSI)MWSGTEMP. (F)FLANGE
RATINGSERVICE111280a1002345678910
&L&"Arial Narrow,Regular"&10&P of
&N&R&9&F/&AINSTRUMENT SPECIFICATIONCitgo
Petroleum Corporation135th Street & New AvenueLemont, IL
60439Flange-type Restrictive OrificesALL ITEMS SHALL COMPLY WITH
GENERAL SPECIFICATION SHEETSMATERIAL: 316SSInstallation notes:1.
Orifice dia. As specified to suit required conditions.2. Gaskets
furnished by vendor.
New Flange Spec Sheet_MonelITEMREV.QTY.TAG. NO.PIPE SIZE
(IN.)SCH.ORIFICE (IN.)FLOW QUANTITY (SCFH)UPSTREAM PRESSURE
(PSIG)DP (PSI)MWSGTEMP. (F)FLANGE
RATINGSERVICE111280a1002345678910
&L&"Arial Narrow,Regular"&10&P of
&N&R&9&F/&AINSTRUMENT SPECIFICATIONCitgo
Petroleum Corporation135th Street & New AvenueLemont, IL
60439Flange-type Restrictive OrificesALL ITEMS SHALL COMPLY WITH
GENERAL SPECIFICATION SHEETSMATERIAL: MonelInstallation notes:1.
Orifice dia. As specified to suit required conditions.2. Gaskets
furnished by vendor.
PropertiesCaution: this sheet calculates properties based on
yellow-highlighted cells. The viscosities will change and are a
function of pressure and temperature, however, the NIST values for
pure components will change so if T or P change update with
NIST.Gas PropertiesProperties using coresponding statesyTc, KPc,
atmVc, cm3/mol-1ZcwCpo, cal/gmol-KMm,
cPHydrogen033.2012.8065.000.31-0.226.912.020.00919Methane0.94190.6045.4099.000.290.018.6616.040.01167Ethane0.05305.4048.17148.000.290.1012.9830.070.00988Propane0.01369.8041.95203.000.280.1518.3044.100.00855Propylene0365.0045.60181.000.280.1515.7842.080.00904ButaneAverage,
Mixture:1.0000198.1345.65102.490.290.018.9817.02k =1.28R,
atm-cm^3/(K-gmole):8.21E+01Temperature, F:100311Pressure,
psig.:90Use initial (1) properties.Viscosity, cP:0.01151From VISC
Sheet - manual entry-- use NIST website for individual m, then use
Wilke's method in spreadsheet to calculate mixture m.m, cP @ 78
psigm, cP @ 90
psig100120100120Methane0.0116610.0120080.0116590.012006Ethane0.00985950.0101790.00988240.010201Propane0.00852980.00883560.00854690.0088525Propylene0.00901250.00934650.00903940.0093723Butane0.0092540.012779
Citgo Employee:k = Cp/(Cp-R) only for ideal gases, i.e.,
adiabatic flow of an ideal gas. For real gases, Cp and Cv must be
derived individually.
RO1RESTRICTIVE ORIFICE ---- Method 1Thin plate orifice
Low-Moderate DPNOT VERY ACCURATE!Rough method provided originally
in an article in Chemical Engineering magazinetb/bore diameter
=0.93P2/P1 =0.05Thin plate, no choked flow.Calculation not
applicable: refer to Kirk-Cunningham method.D, inches; Qg, gas flow
in SCFH (60 F, 1 atm); DP, P1, P2, psia; Sg = Mg/MairLine
Sizetp,mmT1, R; tp, plate thickness.0.51.5Using table from Fluor
specification: "Flange Type Restrictive Orifice"0.751.5Qg:250SCFH @
60 F, 1 atmComplete Property Sheet11.5DP =57.00Tr =2.51from
sheet1.52P1:60psigPr =0.1122.5P2:3psiUsing initial properties @ P1,
T133Mw:1743Sg =0.59manual allowed63T:100deg. Fk =1.2886Plate
Rate300300, 600# ANSI106tp =2.50mmFrom Fluor
table126Z:1.000.98Calculated using virial equations149D1,
nom:2.00in.Sch.:801691812Sat. Curve Test:0.749Test:OKAbbott
Equations are acceptable2012Hot Gas Test:0.433Saturated Area2416B1
=0.135Pr/Tr =0.044Z =1.00B0 =-0.014Pcf =40.98psigChoked Flow - for
thick plateD2 =0.106in.Beta =0.0551716.043CH4M =35.183X2
=0.050.957Selected diameter1.94IDNominal pipe dia. -
inches1.01.52.03.04.06.08.010.012.014.016.018.020.0Pipe dia. -
inches for schedule 40
pipe1.051.612.073.074.036.077.9810.0211.9413.1215.0016.8818.81Pipe
dia. - inches for schedule 80
pipe0.961.501.942.903.835.767.639.5611.3712.5014.3116.1217.94Pipe
dia. - inches for schedule 160
pipe0.821.341.692.623.445.196.818.5010.1311.1912.8114.4416.062.0671.9391.687
&L&G&L&P of &N&C&G Lemont,
Illinois&R&9&F/&AP1:P2:D1:D2:D=Qg/SQRT( DP(P1
+P2)/(2SgT1)78X5440(tp/0.125)X1/5Method assumes, implicitly, that
gas is ideal gas mixture or perfect gas.Flow through a thin plate
is never choked flow. For this to apply, the ratio of tb/bore
diameter must be < 6. (Reference: pg. 13.22, Richard Miller's
"Flow Measurement Engineering Handbook," 3rd ed., McGraw Hill,
1996. Page 13-22 refers to the work of Cunningham (1951) and
Ward-Smith (1979).Kirk-Cunningham applies when P20.995 taken as
Zf=1.00027.71327.711Corrected h-maxFdREAL GAS60.195NOMINALBASEGAS
DPDENSITYCInf.CInf.Cinf for Rosemount 1195 Integral
OrificesCInf.nb(IWC)(lbs./cf)N.D.I.D.bb[D>2.3][2 4000, it is
acceptable to use values from Richard Miller's "Flow Measurement
Engineering Handbook, " Table 9.1:C = C + b/ReDnn = 0.75b =
91.706b2.5b =0.144D =2.00ReD =4,8740.726D 2.3 inches:C = 0.5959 +
0.0312(b)2.1 - 0.184(b)8 + 0.09[b4/(D(1-b4)] - 0.0337[(b)3/D]0.596C
=0.5982 D 2.3 inches:C = 0.5959 + 0.0312(b)2.1 - 0.184(b)8 +
0.039[b4/((1-b4)] - 0.0337[(b)3/D]0.596
&L&G&R&"Century Gothic,Italic"&10This method
is more general.&L&P of &N&C&GLemont,
Illinois&R&"Arial
Narrow,Regular"&9&F/&ADW:Calculated from Fluor table at
the end of the spreadsheet. tP must be small: tb/Do must be < 6
for the sonic vena cava to form beyond the bore diameter. If the
sonic barrier forms in the orifice as it does for thick plates (tb
ratio > 6), then the flow is choked and a larger orifice will be
required to flow the same mass.DW:Based on ideal gas at inlet flow
temperature. Slight error can be expected for saturated conditions
near critical point. K affects Y so a significant deviation will be
a problem. Ideal gas k should not be used if residuals are
large.DW:Cunningham showed that a thin plate orifice is not
restricted by choked flow. Until 2005, it was assumed that Y and C
would be different than for unchoked flow. Kirk presented a new Y
equation for conditions below Pcritcal, whn P2/P1 are below 0.63.
Without these new equations, an error of up to 40%, or more, can be
expected by using standard ASME equations for Y and C.DW:Calculate
Do with goal seek by selecting Wcalc for set, typing in the value
for Wd, and using the value of Do for the change cell.DW:Not all of
the pressure drop across the orifice is lost. As the Beta is
decreased, the permanent loss approaches the tap measurement, which
is always the larger of the two.DW:This is the value used in
Wcalc.DW:Target flow rate.DW:Re is measured for the pipe not the
bore.DW:Wd is the mass flow rate based on Qg and SC
density.DW:Wcalc is the mass flow rate based on Crane equation
2-24.DW:This viscosity is the mixture viscosity from the
"Properties" sheet --- from "VISC." VISC calculates mixture
viscosity using the Wilke equation.DW:Manual input is allowed for
Z. (Although program will calculate Z, calculated Z will be ignored
if yellow cell has value.) In some circumstances Z will not be
calculated: if the Abbott equations do not apply. In this unlikely
event, read the Zo, Z1 values from the appropriate curves,
calculate Z by hand and enter here.Citgo Employee:Temperature
upstream of orifice, i.e., for D1. Final temperature will decrease
as a result of throttling. Usually, adiabatic expansion yields the
lowest pressure drop and temperature drop but isothermal expansion
has been assumed. Isothermal really only applies for long runs of
small pipe.DW:Real gas density at upstream conditions.DW:For the
Abbott equations to apply, an error curve was prepared relating
Tr(y) to Pr(x): Figure 3.16, Smith & Van Ness, "Introduction to
Chemical Engineering Thermodynamics," 4th edition. Above the curve,
the Abbott equations apply, below the curve, the charts for Zo, Z1
must be used. The curve has a break but can be approximated by two
straight line sections: "sat curve" and "hot gas curve."DW:M.M.
Abbott developed equations for Z in terms of a truncated virial
coefficient equation.DW:"Sch." affects the diameter, i.e.,
D1.DW:Below the calculated pressure, Pcf, a vena contracta will
form, beyond it, the gas passes through a sonic barrier. As the
pressure is reduced further, the vena contracta will approach the
bore.P1:P2:D1:Do:W=DPrEquation 2-24, Crane TP 410, adapted on 3.24
of text.1891 Y C d20Flow through a thin plate is never choked flow.
For this to apply, the ratio of tb/bore diameter must be < 6.
(Reference: pg. 13.22, Richard Miller's "Flow Measurement
Engineering Handbook," 3rd ed., McGraw Hill, 1996. Page 13-22
refers to the work of Cunningham (1951) and Ward-Smith (1979). In
2005, Kirk explored the limits of Cunningham's work. He found that
ASME formulas worked fine with adjustment of Y; C could be defined
using ASME and other methods.Kirk-Cunningham applies when P2
