Data sheet Multifunctional Thermostatic Circulation Valve...

Data sheet

Multifunctional Thermostatic Circulation ValveMTCV - Lead free brass

Introduction

The MTCV is a multifunctional thermostatic balancing valve used in domestic hot water installations with circulation.

The MTCV provides a thermal balance in hot water installations by keeping a constant temperature in the system, thus limiting the flow in the circulation pipes to the minimum required level.

To meet the increasing demands placed on the quality of drinking water, Danfoss is introducing the MTCV “Lead free brass” family of valves.

The MTCV “Lead free brass” valves meet the new regulations enforced by the European Drinking Water Directive that comes into effect in December 2013.

Simultaneously, the MTCV can realize a disinfection process by means of 2 features:

• Anautomatic(self-acting)disinfectionmodule-thermo-element(fig.2).

• AnelectroniccontrollerwiththermalactuatorTWAandtemperaturesensorsPT1000(fig.3).

Main functions of the MTCV • Thermostaticbalancingofhotwatersystemswithinthetemperaturerangeof35-60°C-versionA.

• Automatic(self-acting)thermaldisinfectionattemperaturesabove68°Cwithsafetyprotection of the installation to prevent the temperaturerisingabove75°C(automaticallyshuts-offcirculationflow)-version“B”.

• Automaticdisinfectionprocess,electronicallycontrolled, with the possibility of programming the disinfection temperature andduration-version“C”.

• Automaticflushingofthesystembytemporarilylowering the temperature setting to fully open the MTCV valve for a maximum flow.

• Temperaturemeasurementpossibility.• Preventingofunwantedtampering.• Constanttemperaturemeasurementand

monitoring-version“C”.• Shut-offfunctionofthecirculationriserby

meansofoptionalfittingswithabuilt-inballvalve.

• ModularupgradingoftheMTCVvalveduringoperation, under pressurized conditions.

• Servicing-whennecessarythecalibratedthermo-elementcanbereplaced.

Fig. 3Version with electronically controlled disinfection process - “C”

Fig. 1Basic version - A

Fig. 2* Self-acting version with automatic disinfection function - “B” * thermometer is an accessory

1VD.D3.I1.02 © Danfoss 12/2013SMT/SI

Data sheet Multifunctional Thermostatic Circulation Valve MTCV-Lead free brass

Function

Fig. 4 MTCV basic version - A

TheMTCV-isathermostaticself-acting,proportionalvalve.Athermo-element(fig.6elem.4)isplacedinthevalvecone(fig.6elem.3)to react to temperature changes.

When increases the water temperature above thesetpointvalue,thethermo-elementexpandsand the valve’s cone moves towards the valve seat, thus limiting circulation flow.

When decreases the water temperature below thesetpointvalue,thethermo-elementwillopen the valve and allow more flow in the circulation pipe. The valve is in equilibrium (nominalflow=calculatedflow)whenthewatertemperature has reached the value set on the valve.

The MTCV regulating characteristic is shown in fig.13,version1-A.

Whenthewatertemperatureis5°Chigherthanthe set point value, the flow through the valve stops.

Aspecialsealingofthethermo-element protects it against direct contact with water, whichprolongsthedurabilityofthethermo-element and at the same time secures a precise regulation.

Asafetyspring(fig.6elem.6)protectsthethermo-elementfrombeingdamagedwhenthewater temperature exceeds the value on the set point.

Fig. 5 Example of MTCV / basic version / placement in domestic hot water system

Design

1. Valve body 2. Spring 3. Cone 4. Thermo-element 5. O-ring 6. Safetyspring 7. Setting ring 8. Settingknob 9. Plugforcoveringthesetting 10. Cone for disinfection module 11. Safety spring 12. Plugforthermometer13. Plugfordisinfectionmodule

Fig. 6 Design - basic version - A

2 VD.D3.I1.02 © Danfoss 12/2013 SMT/SI

Data sheet Multifunctional Thermostatic Circulation Valve MTCV- Lead free brass

Function

Fig.7 MTCV self-acting version with automatic thermal disinfection function - B* thermometer is accessory

TheMTCVstandardversion-Acaneasilyandquickly be upgraded to the thermal disinfection function against the Legionella bacteria in hot water systems.

Afterremovingtheplugfromthedisinfectionplug(fig.6elem.13)-(thiscanbedoneduringworkingconditions,underpressure)thethermostatic disinfection module can be mounted(fig.9elem.17).

The disinfection module will control the flow according to its regulating characteristics, (fig.13-vesionB-1)thusperformingathermaldisinfection of the hot water installation.

The mounted disinfection module automatically opensaby-passofKvmin=0.15m3/h, which allowsflowforthedisinfection.IntheAversionoftheMTCVthisby-passisalwaysclosedinorder to avoid sedimentation of dirt and calcium. The MTCV can thus be upgraded with the disinfection module even after a long period of workingintheAversionwithoutriskingblockingthe bypass.

TheregulationmoduleinbasicversionAworkswithin the temperature range 35-60°C.Whenthetemperatureofthehotwaterincreasesabove65°Cthedisinfectionprocessstarts-meaningtheflowthroughthemainseat of the MTCV valve stops and the bypass opens for the “disinfection flow”. The regulating function is now performed by the disinfection module, which opens the bypass when the temperatureisabove65°C.

The disinfection process is performed until a temperatureof70°Cisreached.Whenthehotwater temperature is increased further, the flow throughthedisinfectionbypassisreduced(theprocess of thermal balancing of the installation duringdisinfection)andwhenreaching75°Cthe flow stops. This is to protect the hot water installation against corrosion and sedimentation of calcium as well as to lower the risk of scalding.

AthermometercanoptionallybemountedinbothversionAandBinordertomeasureandcontrolthe temperature of the circulating hot water.

Fig. 8 Scheme of hot water installation with circulation - self acting version.

Fig. 9 Self-acting version - B* (* thermometer is accessory)

Design 1-13Asdescribedinfig.6 14 Bypassfordisinfection 15 Thermometer 16 GasketCu 17 Disinfecting module



Function

Fig.10 Version with electronically controlled disinfection process - C

TheMTCVversion“A”and“B”canbeupgradedto an electronic regulated disinfection process (versionC).

Afterremovingthedisinfectionplug(fig.6elem.13)theadaptercanbemounted(fig.12elem.21)andthethermoactuatorTWAcanbemounted.

AtemperaturesensorPT1000hastobemountedinthethermometerhead(fig.12elem.19).Thermo-actuatorandsensorareconnectedtotheelectronicregulatorCCR-2whichallowsan efficient and effective disinfection process in each circulation riser. The main regulation module works within the temperature range 35-60°C.Whenthedisinfectionprocess/thermal-watertreatmentstartsCCR-2controlstheflowthroughMTCVviathermo-actuatorsTWA.BenefitsofanelectronicregulateddisinfectionprocesswithCCR-2are:• Providingfullcontroloverthedisinfection

process in each individual riser.• Optimisationoftotaldisinfectiontime.• Optionalchoiceoftemperatureforthe

disinfection.• Optionalchoiceoftimeforthedisinfection.• On-linemeasurementandmonitoringofthe

water temperature in each individual riser.• Enablingthepossibilityofconnectingtothe

controller in the heat substation or boiler room(i.e.DanfossECL)ortoaBMS(RS485).

Fig. 11A) Indirect heating connection with parallel instantaneous system for domestic hot water production -independent CCR-2 system

B) Indirect heating connection with parallel instantaneous system for domestic hot water production -dependent CCR-2 system

Fig.12 Version with electronically controlled disinfection process - C

Design

1-13 Asdescribedinfig.6 18 Bypass;(positionclosed) 19 TemperaturesensorPT1000 20 GasketCu 21 Adaptertoconnectthermo-

actuatorTWA


B

A


Technical data Max. working pressure ........................................10 barTest pressure ...........................................................16barMax. flow temperature........................................100°CkVSat20°C: -DN20 ...........................................................1.8m3/h -DN15 ............................................................1.5 m3/hHysteresis ....................................................................1.5K

Material of parts in contact with water:Valve body ...................................................................Rg5Spring housing, etc. ............Cuphinalloy(CW724R)O-rings ...................................................................... EPDMSpring, cones .......................................... Stainless steel

Valve - basic version A Code No.

DN15 003Z1515

DN20 003Z1520

Accessories and spare parts

Accessory Comments Code No.

Thermostaticdisinfectionmodule-B DN15/DN20 003Z2021

Fittingswithshut-offballvalve(forallenkey5mm),DN15

G½×Rp½ 003Z1027

G¾×Rp¾ 003Z1028

Thermometer with adapter DN15/DN20 003Z1023

SocketforESMBPT1000 DN15/DN20 003Z1024

Adapterforthermo-actuator DN15/DN20 003Z1022

CCR 2 Control also see enclosure VD.57.U4.02 003Z3850

TemperaturesensorESMBUniversalalso see enclosure VD.57.U4.02

087B1184

Temperature sensor ESMC contact 087N0011

Fittings for soldering Cu 15 mmDN15int. R 1/2”*PexDN18×2only

003Z1034

FittingsforsolderingCu18mm 003Z1035

FittingsforPexpipe15mm 003Z1036

FittingsforPexpipe18mm* 003Z1037

Fittings for soldering Cu 22 mm DN20 int. R 3/4”*PexDN22×2only

003Z1039

FittingsforsolderingCu28mm 003Z1040

FittingsforPexpipe22mm* 003Z1041

ThermoactuatorTWA-NC,230Valso see enclosure VD.57.U4.02

088H3112

ThermoactuatorTWA-NC,24V 088H3110

Ordering



Regulating characteristics

Fig.13 The MTCV regulating characteristics

• BasicversionA• VersionB:

Kvmin=0.15m3/h-min.flowthroughthebypass when main regulation module is closed.

*Kvdis=0.60m3/hforDN20,

*Kvdis=0.50m3/hforDN15-max.flowofthe

disinfection process by a temperature of70°C.

• VersionC: *Kvdis=0.60m

3/hforDN20andDN15- flow through the MTCV when the disinfection module is fully opened (regulationatthermo-actuatorTWA-NC).

* Kvdis - Kv during disinfection process

1 Setting ring

2 Ring with a reference point

3 Plasticcover-unwantedtampering protection

4 Hole for screwdriver

5 Temperature setting screw-Allen-key2.5mm

6 References temperature setting point

Main function setting

Fig.14 MTCV setting of the temperature

Temperaturerange:35-60°CMTCV´sfactorypre-setting50°C

The temperature setting can be made after removingtheplasticcover(3),byliftingitwithascrewdriverusingthehole(4).Thetemperaturesettingscrew(5)mustbeturnedwithanallen-key to match the wanted temperature on the scale with the reference point. The plastic cover (3)mustbepressedbackintoplaceafterthesetting has been made.

It is recommended to control the set temperature with a thermometer. The temperature of the hot water from the last tapping point on the riser must be measured*. The difference between the measured temperature at the last tapping point and the temperature set on the MTCV is due to heat losses in the circulation pipe between the MTCV and the tapping point.

* where TVM valves (thermostatic mixing valves) are installed the temperature must be measured before the TVM valve.


25 35 45 55 65 75 85

Kvs

Kvmin

K vdis

basic disinfection

version B

version C

version A

temperature ˚C

presetting 50 ˚C

flow

21

5

4 3

6

0

10

20

30

40

50

60

70

0 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60

Flo

w te

mpe

ratu

re ˚

C settingat 60 ˚C

setting at 50 ˚Csettingat 35 ˚C

Kv (m3/h)

55

60

65

70

75

80

0 0.10 0.20 0.30 0.40 0.500 0.60

Flo

w te

mpe

ratu

re ˚

C

Kv (m3/h)

version B

version C


Setting procedure The required temperature setting of the MTCV depends on the required temperature at the last tap and the heat losses from the tap to MTCV in the same riser.

Example:Requiredtemperatureatthelasttap: 48°CHeatlossesfromthelasttaptotheMTCV: 3K

Required: correct setting of MTCV

Solution:CorrectsettingofMTCV:48–3=45°C

Note: After new setting use the thermometer to check if the required temperature at the tap is reached and correct the MTCV setting accordingly.

Pressure and flow chart MTCV - DN 15

Differentialpressure1bar,DN15

Fig. 15

Table 1preset preset preset preset preset preset

kv(m3/h)60°C 55°C 50°C 45°C 40°C 35°C

Flow

temperature°C

65 60 55 50 45 40 062.5 57.5 52.5 47.5 42.5 37.5 0.18160 55 50 45 40 35 0.366

57.5 52.5 47.5 42.5 37.5 32.5 0.54255 50 45 40 35 30 0.711

52.5 47.5 42.5 37.5 32.5 0.89950 45 40 35 30 1.062

47.5 42.5 37.5 32.5 1.21445 40 35 30 1.331

42.5 37.5 32.5 1.42040 35 30 1.487

37.5 32.5 1.50535 30 1.505

32.5 1.50530 1.505

Differentialpressure1bar,DN15-disinfectionprocess

Fig. 16



Differentialpressure1bar,DN20Pressure and flow chart MTCV - DN 20

Differentialpressure1bar,DN20-disinfectionprocess

Table 2preset preset preset preset preset preset

kv(m3/h)60°C 55°C 50°C 45°C 40°C 35°C

Flow

temperature°C

65 60 55 50 45 40 062.5 57.5 52.5 47.5 42.5 37.5 0.17260 55 50 45 40 35 0.336

57.5 52.5 47.5 42.5 37.5 32.5 0.55655 50 45 40 35 30 0.738

52.5 47.5 42.5 37.5 32.5 0.92150 45 40 35 30 1.106

47.5 42.5 37.5 32.5 1.28645 40 35 30 1.440

42.5 37.5 32.5 1.57440 35 30 1.671

37.5 32.5 1.73735 30 1.778

Fig. 17

Fig. 18


0

10

20

30

40

50

60

70

0 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00

Flo

w te

mpe

ratu

re ˚

C settingat 60 ˚C

setting at 50 ˚C

settingat 35 ˚C

0.366

Ex. 1

Kv (m3/h)

55

60

65

70

75

80

0 0.10 0.20 0.30 0.40 0.50 0.60 0.70

Kv m3/h

Flo

w te

mpe

ratu

re ˚

C version B

version C


Example of calculation Example: Thecalculationisdonefora3-storeybuildingwith8risers.

Allformulasusedaredescribedinthe"Background"chapterThermalBalance (datasheetVD.57.X1.02).

The following assumptions were used in order to simplify calculation:• Heatlossespermeterofthepipe,

q1=10W/m(*)(* during calculation it is required to calculate heat losses

according to the country-specific standards).

Usuallythecalculatedheatlosesaredependenton :- Thedimensionofthepipe- Thematerialsusedininsulations- Theambienttemperaturewherethepipeis

located- Theefficiencyandconditionofinsulation • Inletofhotwatertemperature,Tsup=55°C• Temperaturedropthroughthesystem,

∆T=5K• Distancebetweenrisers,L=10m• Heightoftherisers,l=10m

• Installationschemeasshownbelow:

Fig. 19 Scheme of installation

I Basic operation

Calculation:• calculationofheatlossesineachriser

(Qr)andheader(Qh) Qr=lriserxq=(10+10)x10=200W Qh=lhoriz.xq=10x10=100W

• The table 3 shows the results of the calculations:

V̇ o

V̇pV̇c

p.

o.

o.

cVV

VV

+=&

Table 3

heat losses

In risers In header Total in eachpart ΣQtotal Factor risers Flow in each

part Total flow

riser Qr(W) Qh(W) (W) (W) Vo(l/h) Vc(l/h)

1 200 100 300 2400 36 412

2 200 100 300 2100 0.09 38 376

3 200 100 300 1800 0.1 40 339

4 200 100 300 1500 0.12 43 299

5 200 100 300 1200 0.14 47 256

6 200 100 300 900 0.18 52 210

7 200 100 300 600 0.25 63 157

8 200 100 300 300 0.4 94 94



• The total flow in the hot water circulation systemiscalculatedusingformula1(see“Background”chapterThermalBalance;datasheetVD.57.X1.02).

hww tcrQ

VΔ

∑=&

&

ΣQ-totalheatlosesininstallation,(kW)

thus:

518.414.2××

=totalCV&

=0.114l/s=412l/h The total flow in hot water circulation system

is:412l/h-thecirculationpumpshallbesizedfor this flow.

• The flow in each riser is calculated using formula4(see.“Background”chapterThermalBalance,page4;datasheetVD.57.X1.02).

Flow in the riser number 1:

po

oco QQ

QVV

+×= &&

thus:

2100200200

412V10 +

×=&

=35.84l/h≅36l/h

Flow in remaining risers should be calculated in the same way.

• The pressure drop in the system Following assumptions were made to simplify calculation:-Linear pressure drop, pl=60Pa/m (Linearpressureisthesameforallpipes)-Local pressure drop is equal to 33 % of

total linear pressure drop, pr=0.33pl

thus: pr=0.33×60=19.8Pa/m≅20Pa/m-For the calculation used

pbasic=pr+pl=60+20=80Pa/m

-Local pressure drop across the MTCV is calculated on the basis of:

20

KvV01.0

ΔpMTCV ⎟⎟

⎠

⎞⎜⎜⎝

⎛ ×=

&

, where: Kv-accordingtofig.19page10

in this case Kv=0.366m3/hforpreset50°C V&0-flowthroughtheMTCVattheflow temperature50°C(l/h)

• When designed flow have been calculated, usethefig.17onpage9.

Please note: during pressure drop calculation across the valve the temperature of circulation water has to be observed. MTCV - Multifunction Thermostatic Circulation Valve has variable Kv value which is dependent on two values: the preset temperature and the temperature of the flow temperature.

When the V&0 andKvareknown,thepressuredropacross MTCV is calculated using the following formula:

20

KvV01.0

ΔpMTCV ⎟⎟

⎠

⎞⎜⎜⎝

⎛ ×=

&

thus:

kPa 6.59366.0

9401.0Δp

2

MTCV=⎟

⎠⎞

⎜⎝⎛ ×

=

∆pMTCV=(0.01x94/0.366)2=6.59kPa

• Differential pressure across the pump:

*ppump=∆pcircuit+∆pMTCV =14.4+6.59=21kPa

Where:∆pcircuit -pressuredropincriticallcircuit

(table4)*ppump -includespressuredropacrossall

devices in circulation installation like: boiler, strainer etc.

Table 4

riser

pressure drop across the MTCVTotal pressure

pump In risers In header pcircuit V0-flow∆mMTCV

pressure drop

(kPa) (kPa) (kPa) (l/h) (kPa) (kPa)

1 1.6 1.6 14.4 36 0.97

21

2 1.6 1.6 12.8 38 1.07

3 1.6 1.6 11.2 40 1.19

4 1.6 1.6 9.6 43 1.38

5 1.6 1.6 8.0 47 1.64

6 1.6 1.6 6.4 52 2.01

7 1.6 1.6 4.8 63 2.96

8 1.6 1.6 3.2 94 6.59



Example of calculation II Disinfection

The heat losses and pressure drop should be calculated according to new conditions.

- inlethotwatertemperatureduringdisinfection Tdis=70°C

- ambienttemperature*Tamb =20°C (*Tamb-accordingtostandardandnorm

obligatory)

1. The heat losses. (see.“Background”chapterThermalBalance,page2,formula1; data sheet VD.57.X1.02) q1=Kj x l x ∆T1 → Kjxl=q1/∆T1 for basic process q2=Kj x l x ∆T2 → Kjxl=q2 /∆T2

for disinfection process Thus :

⎟⎟⎠

⎞⎜⎜⎝

⎛

−−

=ΔΔ

=ambsup

ambdis1

1

212 TT

TTq

TT

qq

for given case:

W/m 14.3

C 20C 55C 20C 70

(W/m) 10q2 =⎟⎠⎞

⎜⎝⎛

°−°°−°

=

In this case during disinfection process heat losses increase for around 43 %.

2. Required flow Duetosequencedisinfectionprocess(stepbystep)onlycriticalcircuitshouldbecalculated. For given case: Qdis=Qr+Qh Qdis =((10+10)+(8×10))×14.3W/m= 1430W=1.43kW

The flow:

l/h 246l/s 0.0684

54.181.43

Vdis ==×

=&

3. The required pressure The required pressure during the disinfection process should be checked pdispump=pdis(circuit)+∆pMTCV

where:

20

KvV01.0

ΔpMTCV ⎟⎟

⎠

⎞⎜⎜⎝

⎛ ×=

&

thus:

kPa 16.81

0.62460.01

Δp2

MTCV =⎟⎠⎞

⎜⎝⎛ ×

=

Due to lower flow comparing to basic condition(412l/h),pressuredropintheinstallation, pcircuit should be recalculated.

2w

Δp2

where : w-velocityofthewater(m/s) Bycomparingconditionsduringbasicoperation and disinfection one can estimate:

2

c

2dis

basicdisV

Vpp ×=

where : Vdis-disinfectionflow(l/h) VC-basicflow(l/h) Thus:

-forfirstpartofinstallation

Pa/m 29

412246

80p2

1dis =⎟

⎠⎞

⎜⎝⎛×=

This calculation should be done for all critical circuit. The table 5 shows the result of calculation. For the critical circuit: pdis(circuit)=0.57+0.68+0.84+1.08+1.48

+2.20+3.93+21.92=32.70kPa

pdispump=pdis(circuit)+∆pMTCV

=32.70+16.81=49.51kPa The pump should be chosen to cover both requirements:

•basic operation,V& 0=412l/handppump =21kPa

• desinfection operationV& 0=246l/handPpump =49.51kPa

Table 5

pressure drop the circuit during disinfection processTotal pressure drop

in critical circuit flow(l/h) new pressure drop lenght pressure drop

basic disinfection (Pa/m) (m) (kPa)

412 246 29 20 0.57

32.70

376 246 34 20 0.68

339 246 42 20 0.84

299 246 54 20 1.08

256 246 74 20 1.48

210 246 110 20 2.20

157 246 196 20 3.93

94 246 548 40 21.92

∑ 32.70


Data sheet Multifunctional Thermostatic Circulation Valve MTCV (Low Lead Content)

Dimensions

Fig. 20

12 VD.D3.I1.02 Produced by Danfoss A/S © 12/2013

Internal threadA a H H1 L L1 Weight

ISO 7/1 mm kgDN15 Rp 1/2 Rp 1/2 79 129 75 215 0.58DN20 Rp 3/4 Rp 3/4 92 129 80 230 0.65

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