Watts 01E051- Pressure Reducing Valves

PRESSURE REDUCING VALVES

01E051-GB

MAIN FEATURES

The pressure reducing valve is able,by varying its pressure drops, tohold the downstream pressure ofthe fluid at a constant level againstchanges in the upstream pressureand flow rate. The pressure redu-cing valve is used:

- in water/plumbing systems: to hold a constant water pressu-re in the water supply main afterthe pressure reducing valve;

- in plumbing systems/sanitary appliances: to maintain the water pressure constantly below the max. permissible value;

- in water/plumbing systems: to save water. By controlling thepressure to the taps, excessive withdrawal of water from thetaps is avoided;

- in compressed air systems: to keep the air pressure constant in the main, regardless of fluctuations in pressure supplied bythe compressors;

- after tanks or storage cylinders: to reduce and stabilize the pressure in the main, which is normally lower.

DRVDiaphragm pressure reducingvalve with single balancedseat. Ensures min. pressuredrops with high flow rates.Downstream pressure set bymeans of the setting screw(4) and is locked with locknut (3)

0501115 1/2”MM0501120 3/4”MM0501125 1”MM0501132 1.1/4”MM0501140 1.1/2”MM0501150 2”MM

Part No. SIZE

DRVMLike DRV, but with pressuregauge Ø50 for reading downstream pressure

0501315 1/2”MM0501320 3/4”MM0501325 1”MM0501332 1.1/4”MM0501340 1.1/2”MM0501350 2”MM

Part No. SIZE

The WATTS Cazzaniga pressure reducing valves SeriesDRV, DRVN and DRVD are of balanced seat type.This means that the inlet pressure, when acting on the twoopenings A and B with the same section, is compensated.Therefore it does not exert any force on the pin-plugsystem when the degree of valve opening changes.Instead, the outlet pressure acts on the diaphragm andhence on the pin-plug system which, therefore, is subjec-ted to two opposing forces, namely: the force exerted bythe outlet pressure tending to close the plug, and thepressure exerted by the spring tending to open it.This results in the pressure reducing valve acting like abalanced seat type having the outlet pressure almostunaffected by variations in upstream pressure.

GENERAL

The difference between the downstream pressure P2measured with zero flow rate and the same pressuremeasured with a general flow rate Q represents thepressure drop DP across the pressure reducing valve. Itdepends on the flow rate as shown in the pressure dropdiagrams.

If it is required for the upstream pressure not to exceed agiven value P2, this should be adjusted to value P2 whenthe flow rate is zero. At flow rate Q, the downstreampressure will be below the value P2 by an amount equal topressure drops DP.When the pressure reducing valve is installed to ensurethat the downstream pressure reaches a given value P2 ata certain flow rate Q, this pressure should be adjusted tovalue P2 + DP when the flow rate is zero. At flow rate Qthe downstream pressure will be equal to P2.

SETTING

The valve selection criterion consists in determining thediameter so that the speed of the fluid does not reachexcessive levels, at nominal flow rate, thus causing exces-sive pressure drops and noisy effluent which are tran-smitted to the supply main. The flow rate-speed diagramsprovide a guide for selecting the valve diameter in the caseof liquids (see water) or gases with pressures of 8 to 10bar (see air).

SIZING

Example 1 (cavitation)Pressure reducing valve with:Inlet pressure P1 = 14 barOutlet pressure P2 = 3 barFrom the cavitation diagram it can be seen that thepressure reducing valve works constantly in the red zone. To avoid rapid deterioration, two valves can be used, oneconnected upstream to the other.Upstream valve: pressure change from 14 to 6 bar(green zone)Downstream valve: pressure change from 6 to 3 bar(green zone).

Example 2 (flow rate)Pressure reducing valve DRV/N with:Inlet pressure (min.) P1 = 8 barOutlet pressure P2 = 4 barMax. flow rate Q = 50 l/min

From the flow rate-speed diagram it can be seen that adiameter of 20 or 25 can be used. The pressure dropdiagram shows that in the two cases:DRV20/N Q = 50 l/min DP = 1.1 barDRV25/N Q = 50 l/min DP = 0.68 bar

EXAMPLES OF SIZING

Flow rate/speed diagram DRV - DRVN

Flow rate

Sp

eed

(m

/s)

DN15

30

20

10

8

1

0,6

0,4

0,2

0,10,1 0,2 0,4 0,6 0,8 2 4 6 10 20 60 200 10001 8 40 100 400 600

10 50 100 1000 100005 500 5000

6

4

2

0,8

Water

Air

m3/h

l/min

DN20

DN25

DN32

DN40

DN50

Flow rate

Sp

eed

(m

/s)

DN65

6

4

1

0,6

0,4

0,2

0,1

4 6 10 20 60 200 10008 40 100 400 600

3 4 5 3001 100

2

0,8

m3/h

l/s

DN80

DN10

0

DN12

5

DN15

0

DN50

DN20

0

2 6 8 10 20 30 40 40 200

Flow rate/speed diagram DRVD

The cavitation diagram shows three zones of valveoperation in relation to the upstream and downstreampressures, namely:zone C: normal duty, no cavitationzone B: medium duty, possible cavitationzone A: heavy duty, the valve cavitates.Continuous operation in the red cavitation zone causesrapid deterioration of the internal parts. If the pressurereducing valve is to be used in the red zone, pleasecontact the WATTS Cazzaniga Engineering Department.

CAVITATION

Water, air and neutral (non aggressive) gases.

APPLICATION

- DVGW approval (Arbeitsblatt W 375)- LGA approval (DVR15 to 32) according to DIN 4109

class I (noise below 20 dB)- SVGW approval (W/TPW101).- TIN approval (Poland)- CSTB approval (NF P 43-006) (DRV15, DRV20).- KTW certification for all materials in contact with water.

APPROVALS

Cavitation diagram

Flow rate - Pressure drop diagram

Flow rate

0,08

0,1

0,2

0,3

2

0,6

0,4

Pre

ssu

re d

rop

[ bar ]

[l/m]

0,8

1

1 2 43 5 6 8 20 3010 40 60 80 100 200 400

DRV50/N DRV40/N DRV32/N DRV25/N DRV20/N DRV15/N

Overall dimensions (mm)

20

A Cavitation zone B Transition zone C Work zone

18

16

14

12

10

8

6

4

2

00 1 2 3

(bar)

(bar

)

Downstream pressure

Inle

t pre

ssur

e

4 5 6 7

A

B

C

DESIGN FEATURES

Body Shot-blasted brass OT58

Cap Shot-blasted brass OT58

Plug Brass OT58

Inlet / outlet connections Brass OT58

Diaphragm NBR with nylon fabric

Seal and O-ring NBR

Spring Galvanized steel

Setting screw and lock nut Brass OT58

Filters Stainless steel

TECHNICAL CHARACTERISTICS

Max. upstream pressure 25 bar

Downstream pressure (outlet) 1.5 to 6 bar

Connections to M / M tailpiece

Downstream pressure adjustment (screw 4) Clockwise rotation: increase in pressureAnti-clockwise pressure: decrease in pressure

Downstream pressure gauge (DRV-M only) Pressure gauge Ø50, scale 0 to 6 bar

Max. operating temperature 70° C

DRV / DRVM

SIZE1/2” 3/4” 1”

1.1/4” 1.1/2”

2”

L97110120140160175

L1152171191211246261

H135155182227255262

H1485866758288

Key:

1. Body2. Cap3. Lock nut4. Setting screw5. Spring6. Diaphragm7. Inlet connection8. Pin9. Plug

10. Guide bushing11. Filters12. Outlet connection

3

2

112

11

109

8

654

7

DRVNDiaphragm pressure reducingvalve with single balancedseat. Ensures min. pressuredrops with high flow rates.Downstream pressure set bymeans of knob (3) withadjustment scale 1 to 6 bar.

0502515 1/2”MM0502520 3/4”MM0502525 1”MM0502532 1.1/4”MM0502540 1.1/2”MM0502550 2”MM

Part No. SIZE

DRVMNLike DRVN, but with pressuregauge Ø50 for reading down-stream pressure.

0502615 1/2”MM0502620 3/4”MM0502625 1”MM0502632 1.1/4”MM0502640 1.1/2”MM0502650 2”MM

Part No. SIZE


APPLICATION

- DVGW approval (Arbeitsblatt W 375) - LGA approval (DRV15/N to DRV32/N) according to DIN

4109 class I (noise below 20 dB)- CSTB approval (NF P 43-006) (DRV15/N, DRV20/N).- KTW certification for all materials in contact with water

APPROVALS


0,08

0,1

0,2

0,3

2

0,6

0,4

Pre

ssu

re d

rop

Flow rate

[ bar ]

[l/m]

0,8

1

1 2 43 5 6 8 20 3010 40 60 80 100 200 400

DRV50/N DRV40/N DRV32/N DRV25/N

DRV20/N DRV15/N


DRVN / DRVMN

SIZE1/2” 3/4” 1”

1.1/4” 1.1/2”

2”

L97110120140160175

L1152171191211246261

H135155182227255262

H1485866758288

DESIGN FEATURES

Body Shot-blasted brass OT58

Cap Reinforced plastic

Plug Brass OT58

Inlet / outlet connections Brass OT58

Diaphragm NBR with nylon fabric

Seal and O-ring NBR


Setting screw Brass OT58




Downstream pressure (outlet) 1.5 to 6 bar

Connections to M / M tailpiece

Downstream pressure adjustment (knob 3) Clockwise rotation: increase in pressureAnti-clockwise pressure: decrease in pressure

Downstream pressure gauge (DRV-M/N only) Pressure gauge Ø 50, scale 0 to 6 bar


Key:

1. Body2. Cap3. Adjusting knob4. Setting screw5. Spring6. Diaphragm7. Inlet connection8. Pin9. Plug

10. Filters11. Outlet connection

1

10

11

2

3

4

5

6

8

9

7

U5B(WATTS Patent, U.S. PatentN° 3. 115. 154)Diaphragm pressure reducing valve,single seated, with spring. Ensuresmin. pressure drops with high flowrates. Provided with upstream filterhaving ample surface and separateconnection for easy cleaning.Downstream pressure set by meansof screw (3). Fitted with by-passvalve, it allows freeing on theupstream main any overpressure atdownstream side (generated, forexample, by expansion of water inthe water heaters).

1506115 1/2”FF1506120 3/4”FF1506125 1”FF1506132 1.1/4”FF1506140 1.1/2”FF1506150 2”FF

Part No. SIZEWater, air and neutral (non aggressive) gases.

APPLICATION

- ASSE, ANSI, CSA, UPC (USA) approvals- WATTS Patent, U.S. Patent N° 3. 115. 154

APPROVALS


0,1

2

1

0,8

1000 2000 4.000 6.000 10000 20000 40000

Pre

ssu

re d

rop

Flow rate

[ bar ]

0,6

0,4

0,3

0,2

0,08

0,06

0,04

0,03

DN50

DN40

DN32

DN25 DN

20

DN

15

[ l/h ]


U5B

WATTS Patent, U.S. Patent N° 3. 115. 154

SIZE1/2” 3/4” 1”

1.1/4” 1.1/2”

2”

L146162171203241279

H175184203213248311

H1484851577683

BY-PASS

UPSTREAMPRESSURE

EXPANSION

PLUG

REDUCEDPRESSURE

4

5

146

10 11 12 13

198

7

2

3 Key:

1. Body2. Cap3. Setting screw4. Lock nut 5. Spring6. Inlet connection7. Diaphragm8. Valve seat9. Outlet connection

10. Filter11. Filter cap12. Plug13. Guide bushing14. By-pass



Downstream pressure (outlet) Adjustable 1.5 to 5 bar

Upstream connection to F threaded tailpiece

Downstream connection F threaded

Downstream pressure adjustment (screw 3) Clockwise rotation: increase in pressure Anti-clockwise pressure: decrease in pressure


DESIGN FEATURES

Body Bronze

Cap Cast iron

Plug Stainless steel

Inlet connection Bronze

Diaphragm Nordel with nylon fabric

Seal and O-ring NBR


Setting screw and lock nut Galvanized steel


DRVD16Flanged pressurereducing valve withsingle balanced seatand spring. Ensuresmin. pressure dropswith high flow rates.Downstream pressureset by means of screw(9). Nodular cast ironbody faced with epoxyresins.

DRVD25Like DRVD16 but withmax. inlet pressure:25 bar.

DRVD40Like DRVD16 butwith max. inletpressure: 40 bar.


APPLICATION

PN: 16 barPout: 1.5-6 bar0504053 DRVD50/16 2" DN500504068 DRVD65/16 2"1/2 DN650504083 DRVD80/16 3" DN800504103 DRVD100/16 4" DN1000504128 DRVD125/16 5" DN1250504153 DRVD150/16 6" DN1500504203 DRVD200/16 8" DN200

Pout: 2-8 bar0504054 DRVD50/16/2-8 2" DN500504069 DRVD65/16/2-8 2"1/2 DN650504084 DRVD80/16/2-8 3" DN800504104 DRVD100/16/2-8 4" DN1000504129 DRVD125/16/2-8 5" DN1250504154 DRVD150/16/2-8 6" DN1500504204 DRVD200/16/2-8 8" DN200


PN: 40 barPout: 1.5-6 bar0504056 DRVD50/40 2" DN500504071 DRVD65/40 2"1/2 DN650504086 DRVD80/40 3" DN800504106 DRVD100/40 4" DN1000504131 DRVD125/40 5" DN1250504156 DRVD150/40 6" DN150

Pout: 2-8 bar0504057 DRVD50/40/2-8 2" DN500504072 DRVD65/40/2-8 2"1/2 DN650504087 DRVD80/40/2-8 3" DN800504107 DRVD100/40/2-8 4" DN1000504132 DRVD125/40/2-8 5" DN1250504157 DRVD150/40/2-8 6" DN150

Pout: 4-12 bar0504058 DRVD50/40/4-12 2" DN500504073 DRVD65/40/4-12 2"1/2 DN650504088 DRVD80/40/4-12 3" DN800504108 DRVD100/40/4-12 4" DN1000504133 DRVD125/40/4-12 5" DN1250504158 DRVD150/40/4-12 6" DN150

PN: 25 barPout: 1.5-6 bar0504050 DRVD50/25 2" DN500504065 DRVD65/25 2"1/2 DN650504080 DRVD80/25 3" DN800504100 DRVD100/25 4" DN1000504125 DRVD125/25 5" DN1250504150 DRVD150/25 6" DN1500504200 DRVD200/25 8" DN200




Max. upstream pressure 16 - 25 - 40 bar (ND200 only up to 25 bar)

Downstream pressure (outlet) 1.5 to 6 bar (standard)2 to 8 bar (optional)4 to 12 bar (optional)

Downstream pressure adjustment Clockwise rotation: increase in pressureAnti-clockwise pressure: decrease in pressure

Connections Flanged according to UNI2223 (NP16 - 25 - 40)ND200 only NP16 and NP25

Pressure gauge connections G 1/4 " ND50 to ND65(upstream and downstream) G 3/8" ND80 to ND200


DESIGN FEATURES

Body Nodular cast ironGS400-15

Cap Nodular cast ironGS400-15

Plug (ND 50 to 100) Brass(ND 125 to 200) Galvanized steel

Seal NBR

Lip seal NBR

Seal ring Bronze

Guide bushings Bronze

Spring Faced steel

Setting screw and lock nut Galvanized steel

Finish Epoxy resins (blue RAL 5017)


0,1

Pre

ssu

re d

rop

Flow rate

[ bar]

0,2

0,3

0,4

0,6

0,8

1

1,5

50 60 80 100 200 300 400 600 800 1000 2000 3000 5000 [ l/min]

DN200 DN150 DN125 DN100 DN80

DN65 DN50


DRVD

Key:

1. Body2. Cap3. Plug4. Seal5. Spring6. Seal ring7. Guide bushings8. Lip seal9. Setting screw

10. Cap screws

9

2

5

10

8

7

36

4

1

SIZE506580

100125150200

L230290310350400450550

H3834404905617128391684

H18390100121152169234

B PN16165185200220250285340

B PN25165185200235270300360

B PN40165185200235270300--

WATTS Cazzaniga S.p.A.Via Parco, snc - 20046 Biassono (MI) - Italy

Phone ++39 039 49.86.1 - Fax ++ 39 039 49.86.285www.wattseurope.com e-mail: [email protected]

The descriptions and photographs contained in this product specification sheet are supplied by way of information only and are not binding. WATTS CAZZANIGA reserves the right to carry out any technical and design improvements to its products without prior notice. G

1- D

RV-

DR

VM

- G

B -

01/

’02

Watts 01E051- Pressure Reducing Valves

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