Pressure Reducing Valves

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Pressure Reducing Valves

IntroductionThe importance of managing and reducing waterconsumption has never been so great, as changes in bothour natural and built environments have brought abouta greater awareness of the value of water. As a result thereare increasing social and legislative demands for us all toimprove the way we control water, often involvingincreasingly sophisticated water systems. It has beencalculated that a pressure reduction from 6 to 3 bar would,on average, reduce water consumption for a family of four

by 29%. JET range pressure reducing valves (PRVs)have been designed to allow simple, reliable pressurereduction and stabilisation in domestic, commercial andindustrial applications. The result of this design processis a valve that benefits from sufficiently high flow ratesand robust construction to meet commercial requirements,within a compact body that meets the demands of thedomestic customer for an aesthetically pleasing, easilyunderstandable product.

Design CriteriaThe range comprises two models, sizes;

• DN15 to DN25 that have BSP ends andcompression adaptors for connectingto copper tube.

• DN32 to DN50 are supplied complete with maleBSP unions.

The valves are corrosion resistant in accordance with BS EN12502 and are WRAS approved, (certification) nos. 0605126and 0012135.

There is an integral filter on the inlet side to protect the seatfrom damage caused by debris from the supply.

JET range PRVs are designed to be 'driptight' under 'no flow' conditions.

Valves are tested to DVGW flow rates andnoise levels.

All of the valves are set by their dial up top, with the setpressure directly indicated on the set point scale.Although the need for pressure gauges whilst settingis eliminated, gauge ports are provided for checkingthe downstream pressure as part of a regularmaintenance programme.

Typical Applications

JET range PRVs are the solution to problems causedby unstable or undesirably high pressures in domestic,

commercial and industrial applications.

A valve may serve an individual appliance or outlet,or a complete building, zone or process.

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Examples Include:• High rise buildings or where booster sets have been used,to ensure that pressure is evenly distributed across eachresidence or zone.

• The rising main of a dwelling in areas, where the mainssupply is subject to fluctuation or is excessively high.

• To protect costly equipment that is sensitive to or could bedamaged by high or fluctuating pressures.

• Where it is necessary to constantly maintain the correctpressure to safety critical equipment, such as unvented hotwater storage systems.

Code Size Dimensions (mm) Flow Wt.

DN (ØF) ØC ØM L L1 H H1 H2 Kv Kg

K74263 15 15 20 110 95 98 55.2 26 2.60 0.60

K74264 20 22 25 110 95 98 55.2 26 2.80 0.64

K74265 25 28 32 114 97 98 55.2 26 3.00 0.74

Code Size Dimensions (mm) Flow Wt.

DN (ØD) ØD1 L L1 H H1 Kv Kg

K74286 32 61 200 105 111 64 5.9 2.0

K74287 40 82 225 130 173 126 12.6 3.3

K74288 50 82 255 140 173 126 12.0 4.5

ØM ØF ØC

L

L1

L

L1

ØD1

ØD

H2

H1

H1

H

H

Dimensions and Materials of Construction 15mm to 28mm

1

1

2

3

4

5

6

7

2

3

4

6

7

910

11

12

13

14

8

5

BODY (BRASS)

NOZZLE INSERT (POM)

VALVE SPINDLE (BRASS)

CONE DISC (BRASS)

HEXAGON SCREW (BRASS)

DISC (BRASS)

JOINT RING SEAL (NBR)

8

9

10

11

12

13

14

O-RING (NBR)

O-RING (NBR)

STRAINER (STAINLESS STEEL)

SPRING BONNET (CAPRON PA6)

ADJUSTING SCREW (BRASS)

REGULATING HANDLE (CAPRON PA6)

SPRING (SPRING STEEL)

1

1

2

2

3

3

4

4

5

5

6

6

7

7

BODY (DZR BRASS)

UNION NUT (DZR BRASS)

TAILPIECE (DZR BRASS)

CONE DISC (HOSTAFORM)

NOZZLE INSERT (HOSTAFORM)

ADJUSTING SCREW (BRASS)

STRAINER (STAINLESS STEEL)

8

8

99

10

1011

1112

12

13

13

1414

STRAINER (STAINLESS STEEL)

JOINT RING SEAL (NBR)

GROOVE RING (NBR)

'O' RING (NBR)

SPRING BONNET (CAPRON PA6)

SPRING (SPRING STEEL)

STRAINER PLUG (CAPRON PA6)

Optional Jet range Vertical (Bottom Entry) Pressure Gauges. 0-6 bar N20510 0-16 bar N20512

32mm to 50mm

*Barrier Pipes Copper Tube *Press Fittings *Plastics

Optional Jet range Horizontal (Rear Entry) Pressure Gauges. 0-6 bar N20511 0-16 bar N20513

System Requirements

JET range PRVs are suitable for use with water,compressed air and other inert fluids within thefollowing parameters:

Maximum Inlet Pressure 16.0 bar.Outlet Pressure 1.5 to 6.0 bar.Maximum Temperature 15-28mm 70˚C 32-50mm 40˚C.Minimum Pressure Drop 1.0 bar.

It is important to correctly size the valve for theapplication, the correct size of valve is not necessarily thesame as the line in which it is fitted.

A safety relief valve should be fitted downstream of thevalve but upstream of any equipment that might bedamaged by excessive pressure, to ensure reliable service.

It is good practice, and we recommend that a filteror strainer is installed on the inlet and that isolation valvesare fitted either side of the valve.

Valves must be fitted in accordance with the instructionsthat are provided with the valve.

Valve Sizing

Sizing Examples

WaterFlow velocities should be within the blueshaded area, between 1.0 and 2.0 m/s. Indomestic applications the velocity shouldbe kept below 1.5 m/s.

Example AThe required flow of water to a dwelling is60 l/min (3.6 m3/h). By drawing a verticalline from the required flow rate until itintersects the flow line of valve(s) in theblue zone, then drawing a horizontal lineto the vertical axis, we can see thatvelocity through a 32mm valvewould be 1.25 m/s or through a 25mmvalve would be 2.0 m/s. In a domesticapplication a 32mm valve wouldbe selected, in a commercial or industrialenvironment where slightly more noise ispermissible, a 25mm valve would suffice.

AirAcceptable flow velocites range between10 and 20 m/s, as shown in the greyshaded area.

Example BA capacity of 40 m3/h is required.The valve size that intersects a horizontalline from 40 m3/h in the grey areais 32mm.

Flow rate m3/h

Flow rate l/min

Flowvelocitym/s

For further information telephone our Technical Heating Helplineon 01926 705 237 or visit our website at www.pipecenter.co.uk

Whilst every care has been taken to ensure that the information included in thisdocument was accurate at the time of printing, we reserve the right to changespecifications at any time. The photographs reproduced in this publication arewithin the constraints of the printing process and are NOT to be used for matchingpurposes. E&OE.

Ref: 1848