methven nefa pressure reducing valves reference

1

Product Range • 2011

PRESSURE CONVERSION

kPa psi meters Gauge Head of Water

feet 10 1 3.5

4

5

6

7

8

9

10

20

30

40

2

3

4

5

6

7

8

9

10

11

12

20

30

40

50

60

70

80

90

100

200

300

400

500

600

700

800

900

1000

1.5

2

3

8

10

20

30

40

50

60

70

80

90

100

120

140

4

5

7

9

6

Pressure

mm

Length

in

10

1

2

3

4

5

6

20

30

40

50

60

70

80

90

100

110

120

130

140

150

Quick pressure conversions can be read off scales. e.g. 7.6 m

H2 O

= 25 ftH2 O

= 75 kPa = 11 psi approx.

kPabar

m H

2 Opsi

ft H2 O

1 kPa1

0.010.10197

0.14500.3346

1 bar100

110.197

14.5033.455

1 m H

2 O9.807

0.098071

1.42233.2808

1 psi6.895

0.068950.7031

12.3067

1 ft H2 O

2.9890.02989

0.30480.4335

1

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NVERT IN

TO

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When printed check length scale with rule.

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3

INTRODUCTION

INDEX

Pressure Reducing Feed Valve . . . . . . . . . . . 4

Pressure and Vacuum Relief Valve . . . . . . . . 4

Temperature Limiting Valve . . . . . . . . . . . . 8

Pressure Limiting Valve . . . . . . . . . . . . . .10

Mains Pressure Inlet Control Valve . . . . . . . . 12

Mains Pressure Tempering Valve . . . . . . . . . 14

High Performance Solar Tempering Valve . . . . .16

Cold Water Expansion Valve . . . . . . . . . . . . 18

15mm 3-in-1 Filter Stopcock & Non-Return Valve . . 20

20mm 3-in-1 Filter Stopcock & Non-Return Valve . . .22

Water Heater Installation Checklist . . . . . . . .24

Mains Pressure Installation Guidelines . . . . . .25

Low Pressure Installation Guidelines . . . . . . 26

Troubleshooting Guide . . . . . . . . . . . . . 30

NEFA Valve Packs . . . . . . . . . . . . . . . . .32

NEFA Spare Parts & Service Kits . . . . . . . . . .34

NEFA valves are designed and manufactured to New Zealand Standards and comply with the requirements of the New Zealand Building Code. This booklet has been compiled to assist you with the installation of NEFA products.Installation of valves should always be carried out by a qualified plumber and must comply with the requirements of the New Zealand Building Code and Local Territorial Authority. Refer to the Building Code Compliance Document G12 Water Supplies available from the Department of Building and Housing .While every effort has been made to ensure the accuracy of information included in this publication, the publisher takes no responsibility for errors or omissions .This publication is copyright protected and all rights are reserved .

4

FEATURES

SPECIFICATIONS

PRODUCT CODES

Forged Dezincification Resistant (DR) •brass bodySuperior flow rate •Adjustable outlet pressure •Silicone diaphragm and Jumper •WasherAcetal valve seat •Easily serviced •Complies with the •requirements of NZBC G12

Conforms to NZS:4608 •Factory set outlet pressures: 3.7 m/7.6 m/12.2 m •Maximum inlet pressure 2000 kPa •Maximum temperature 60°C •For 3.7 m / 7.6 m - Settable from 2.5 m to 11 m • Adjustment 1 turn approx 600 mm headFor 12.2 m - Settable from 3 m to 18 m • Adjustment 1 turn approx 1 m headFlow Rates at constant inlet pressure •

Inlet kPa 3.7 m 7.6 m / 12.2 m300 kPa 42 l/min 43 l/min

500 kPa 50 l/min 55 l/min


Connections: Inlet 15 mm (½ BSP) male • Outlet 20 mm (¾ BSP) maleOverall length 145 mm •Main body diameter 125 mm •

NFV3715 3.7 m NEFA Pressure Reducing Feed ValveNFV7615 7.6 m NEFA Pressure Reducing Feed ValveNFV12215 12.2 m NEFA Pressure Reducing Feed Valve

5

PRESSURE REDUCING FEED VALVE

INSTALLATION

IMPORTANT

Fig 1.

The NEFA Pressure Reducing Feed Valve can be installed in any •orientation . But for ease of service install with the cap to the top .Factory setting allows for the NEFA Pressure and Vacuum Relief •Valve to be fitted 1m above the NEFA Feed Valve. If they are installed level undo lock nut and turn adjustment screw two turns out of body.The valve should not be installed in the ground or in a situation •where it could be subject to freezing.The valve should be installed where it can be easily accessed and •when inside buildings above a safe tray.

Refer to Installation Guide, Pages 24 - 29 for detailed instructions.

The water supply to a low pressure storage water heater must not •exceed the maximum working pressure stated by the manufacturer. The NEFA Pressure Reducing Valve (Feed Valve) regulates the water supply pressure to the water heater to a suitable safe value.Install a NEFA 3-in-1 Filter Stopcock before the NEFA Feed Valve. •

capbridge

jet

diaphragm

adjusting screw

forkjumper washer

6

PRESSURE & VACUUM RELIEF VALVE

FEATURES

SPECIFICATIONS

PRODUCT CODES

Conforms to NZS:4608 •Factory set pressures 3.7 m/7.6 m/12.2 m •Heat Rating 8 kW •Maximum temperature 99°C •Connections: Inlet: 20 mm (¾ BSP) male • Drain: 15 mm (½ BSP) maleIntegral vacuum relief •Overall length 105 mm •Diameter 85mm •

NRV37 3.7 m NEFA Pressure & Vacuum Relief ValveNRV76 7.6 m NEFA Pressure & Vacuum Relief ValveNRV122 12.2 m NEFA Pressure & Vacuum Relief Valve

Forged Dezincification Resistant (DR) •brass bodyEasy to service •Withstands boiling temperatures •Tamper proof; relief pressure •permanently setVacuum breaking jumper; •prevents cylinder implosion on drainingIntegral vacuum break in •outlet body; providing air break in drain lineComplies with the requirements of •NZBC G12

7

PRESSURE & VACUUM RELIEF VALVE

INSTALLATION

IMPORTANT

Fig 2.

The NEFA Relief Valve must only be installed on a thermostatically •controlled hot water system. Maximum heating capacity 8 kW per valveThe drain line must not rise above the NEFA Relief Valve. It should •run at a down grade out to atmosphere, to a point where the outlet cannot be obstructed or blocked and where expansion, or other vented water will not cause a hazard or a nuisance . It should not exceed 9 m in length and include not more than three 90° bends.


When factory set, allowance is made for the NEFA Relief Valve to be •fitted 1 m above the NEFA Pressure Reducing Feed Valve. If they are installed at the same level, as in an under sink installation, undo the NEFA Feed Valve lock nut and turn adjustment screw two turns anticlockwise.When servicing NEFA Relief Valves always use the original spring. •Springs are not replaceable .When draining a water heating cylinder, the NEFA Relief Valve must •be disconnected to ensure that adequate air can return to the cylinder to prevent cylinder collapse.A NEFA Relief Valve must not be installed where there is a risk of the •valve freezing .The NEFA Relief Valve must not be installed on to a cylinder with an •uncontrolled heat source i.e. solar or wetback.If the NEFA Relief Valve is fitted in a horizontal pipe run, the integral •vacuum relief vent must be to the top .If the vacuum relief vent plug supplied with the NEFA Relief Valve is •to be fitted to the Relief Valve body an alternative air break must be fitted in the drain line.

flap

diaphragm assembly

spring

vacuum break

8

TEMPERATURE LIMITING VALVELOW PRESSURE

FEATURES

SPECIFICATIONS

PRODUCT CODES

SETTING TEMPERATURE

Cast Dezincification •Resistant (DR) brass bodyAdjustable from 30°C to 65°C •Fail Safe: • Failure of cold water supply causes valve to close and shut off hot flowConfigured for easy installation •Non-return fitted to •stop thermosyphonServiceable •Complies with the requirements of NZBC G12 •

NTLV NEFA Temperature Limiting Valve

Conforms to NZS:4617 •Connections: All 20 mm ( ¾ BSP) male •Factory set outlet temp 55°C •Adjustable 30°C to 65°C •Minimum 20 l/min at 35 kPa (3.5 m head) •Maximum hot water temp 99°C •

Tempering valves must be commissioned at time of installation. The delivered hot water temperature at any sanitary fixture used for •personal hygiene shall not exceed:a) 45°C for early childhood centres, schools, old people’s homes, institutions for people with psychiatric or physical disabilities, hospitals, andb) 55°C for all other buildings.Before setting the valve, ensure the hot water source is switched on and •supplying water within the specified hot water temperature limits. The recommended temperature differential hot supply/mixed outlet •temperature to ensure thermal shut off is 15°C.At a flow rate of not less than 4 litres/minute, allow the water to flow •1-2 minutes to ensure the mixed water temperature has stabilised. Measure temperature at nearest outlet to tempering valve . •The set outlet temperature is adjusted by turning the adjusting screw •in the cover of the valve with a screwdriver. Clockwise decreases the temperature. Anticlockwise increases the temperature.

9

TEMPERATURE LIMITING VALVELOW PRESSURE

INSTALLATION

IMPORTANT

Fig 3.

The NEFA TLV can be installed in any orientation but ensure that the •temperature adjusting screw is accessible.Make up pipe runs to the NEFA TLV with 20mm copper pipe. Do not •braze or solder near valve .Ensure that the NEFA TLV is positioned a minimum of 350mm from •the hot outlet of the water heater .Ensure that hot and cold supply pressures to the inlets of the NEFA •TLV are equal. (Note the NEFA Cold Water Expansion Valve has a 20mm port to allow a simple pipe run to TLV).On header tanks and low head installations the NEFA TLV should •be positioned as low as possible (at base of cylinder) to increase performance .When installing in a wetback system try to install as far from cylinder •as possible to allow for cooling (maximum 90°C).Alternatively the NEFA TLV may be installed close to the outlets •being serviced, but the supply pressures at the inlets to the NEFA TLV must be equal .


Never install a Temperature Limiting Valve directly •onto the outlet of the hot water cylinder.The NEFA TLV must not obstruct the hot water •cylinder vent or NEFA Relief Valve. In the event of high temperature the NEFA TLV will shut the hot supply and not allow the vent or relief valve to relieve pressure in the cylinder.Where inlet supply pressures are not equal an •additional non-return valve should be fitted on the hot water supply line.

adjusting screw

mixed flow

hot flow

cold flowvalve assembly

thermostatic element

10

PRESSURE LIMITING VALVE

FEATURES

SPECIFICATIONS

PRODUCT CODES

NEPLV350MM20 350 kPa NEFA Pressure Limiting Valve

NEPLV500MM20 500 kPa NEFA Pressure Limiting Valve

DR brass construction •Compact size •Superior flow rate •Pressure compensated •Dry spring construction •Ideal for protection of taps, pipe •work and appliances from high supply pressuresComplies with the requirements of •NZBC G12

Conforms to NZS:4608 •Factory set outlet pressures 350 kPa, 500 kPa •Max inlet pressure 2000kPa •Flow Rates at constant inlet pressure •

Inlet kPa 350 kPa 500 kPa


Connections: Inlet and Outlet 20 mm (¾ BSP) male. •Overall length 85 mm •Main body diameter 40 mm •Maximum temperature 80°C •

11

PRESSURE LIMITING VALVE

INSTALLATION

IMPORTANT

Fig 4.

Install the NEFA Pressure Limiting Valve at entry to household to •equalise complete system and protect tapware and appliances from excessive pressure .Install with flow in direction of arrow marked on body. •Can be installed vertical or horizontal . •The valve should not be installed in the ground or in a situation •where it could be subject to freezing.The valve should be installed where it can be easily accessed. •


Install a NEFA 3-in-1 Filter Stopcock before the NEFA Pressure •Limiting Valve .The NEFA Pressure Limiting Valve is factory set. It cannot be •serviced and should not be dismantled .

jumpercontrol spring

color codedset pressure

valve seat

12

MAINS PRESSURE INLET CONTROL VALVE4-in-1 ISOLATION, FILTER, PRESSURE LIMITING & NON-RETURN

FEATURES

SPECIFICATIONS

PRODUCT CODES

PRESSURE ADJUSTMENTThe NPC is factory set as indicated on the valve; however the set •outlet pressure can be increased or decreased if required . Using a screwdriver rotate the adjusting screw shown in Fig 5. to achive the desired outlet pressure .To increase the set pressure, turn the screwdriver clockwise (+). To •decrease the set pressure, turn the screwdriver anti-clockwise (-).

NPC500 500 kPa NEFA Mains Pressure Inlet Control Valve

Cast Dezincification Resistant •(DR) brass bodySuperior flow rate •Pressure compensated •Set pressure adjustable •Built-in Non-return valve •prevents back flowFilter can be •cleaned without shutting off any other valveProtection for entire household; taps, pipe- •work and appliances from high supply pressures60 mesh stainless steel filter efficiently prevents damage •to hot water system by filtering foreign particlesComplies with the requirements of NZBC G12 •

Conforms to NZS:4608 •Maximum inlet pressure 2000 kPa •Set pressure adjustable 100 kPa to 600 kPa •Flow rate of 112 l/min on 20 mm pipe work at 700 kPa supply pressure •20 mm (¾ BSP) male inlet and outlet •Overall length 145 mm, main body diameter 53 mm •Maximum temperature 65°C •

13

MAINS PRESSURE INLET CONTROL VALVE4-in-1 ISOLATION, FILTER, PRESSURE LIMITING & NON-RETURN

INSTALLATION

SERVICING

Fig 5.

A NEFA NPC500 Mains Pressure Inlet Control Valve should be •installed in the main water supply at point of entry. This will provide a point of isolation, a filtered water supply and balanced water pressure to the whole house, protecting tapware and appliances from excessive pressure .The valve should be installed where it can be easily accessed, and •when inside buildings above a safe tray where water from servicing the filter will not cause damage.The NEFA Mains Pressure Inlet Control Valve can be installed in •any orientation, the recommended orientation is with the filter cap facing down to allow foreign particles to fall away when the filter is removed for cleaning .


To remove and clean the filter (Refer Fig 5.): •Turn the isolation control clockwise to the closed position.1 . Unscrew the filter cap.2 . Withdraw the filter and clean it.3 .

To reassemble, reverse the above procedure. Care should be taken •not to damage the filter.To ensure full flow it is recommended that the filter should be •inspected and cleaned at 12 month intervals or more often if required .

isolation hand controlset pressure adjustment

filter cap

filter

jumper non–return

diaphragm

14

MAINS PRESSURE TEMPERING VALVE

FEATURES

SPECIFICATIONS

PRODUCT CODES

NMTV NEFA Mains Pressure Tempering Valve

Provides safe controlled water temperature to •sanitary outletsCast DR brass body •Fail Safe: • Failure of cold water supply causes valve to close and shut off hot flowAdvanced polymers give greater resistance •to calcium depositsFactory tested and set at 55ºC adjustable from •35ºC to 58ºCIntegral Non-Return on hot and cold - ideal for •commercial installationsTamper proof adjustment special tool supplied •Maximum Hot Inlet Temperature 90°C •

Conforms to: NZS4617:1989 •Connections: 20 mm (¾ BSP) male •Recommended outlet temperature range: 45°C to 55°C • (2)

Factory setting (must be commissioned on site): 55°C nominal •Accuracy of mixed outlet temperature: ± 3°C •Cold water supply: 5°C to 25°C •Hot water supply: 60°C to 90°C • (1)

Hot water / mixed water temperature differential: 15°C minimum •Supply pressure – static: 1600 kPa maximum •Supply pressure – dynamic: 200 kPa minimum • 500 kPa maximum •Max permitted pressure variations at either inlet: ± 10% maximum • (4,5)

(from supply pressure at commissioning)Pressure supply differential – dynamic : 3:1 maximum • (3)

(at time of commissioning)Minimum flow rate: 4 litres/minute •

Notes:The Building Code Approved Document G12 clause 6.14 states that water shall be stored at 1) not less than 60°C to inhibit the growth of legionella bacteria. To obtain good tempering valve response the cylinder thermostat should be set at a minimum of 65°C.The valve can be set as low as 35°C or as high as 58°C, depending on site conditions. (These 2) temperatures are outside the optimum working range of the valve and the requirements of G12).The maximum ratio permitted between supply pressures, under dynamic flow operation. 3) It is recommended at time of commissioning that hot and cold pressures be as equal as possible .The maximum permitted pressure variation in either supply from commissioning pressures 4) in order to maintain the outlet temperature to ±3°C.Note: Steps should be taken to eliminate any causes of rapid changes in supply pressures, as 5) this may result in an outlet temperature spike greater than ±3°C from commissioned temperature. If a spike occurs it may take a few seconds for the temperature to stabilise back to within ±3°C.

15

MAINS PRESSURE TEMPERING VALVE

INSTALLATION

IMPORTANT

Fig 6.

Do not install an NMTV directly onto a hot water cylinder. It is •recommended that the valve be installed as close to the hot water source as possible. For optimum performance install with a 150mm thermosyphon between the cylinder outlet and hot inlet. (Refer Fig 10. Page 25).Strainers are essential to prevent debris entering the NMTV that could •prevent it working effectively. All NMTV installations should have line strainers fitted. It is recommended that a NEFA NPC500 valve (with filter/strainer) is installed upstream of the cold inlet.Where installing into installations with separate hot and cold supply’s install •a non-return valve on hot water supply or use the NEFA high performance solar tempering valve .


Tempering valves must be commissioned at time of installation. The delivered hot water temperature at any sanitary fixture used for •personal hygiene shall not exceed:a) 45°C for early childhood centres, schools, old people’s homes, institutions for people with psychiatric or physical disabilities, hospitals, andb) 55°C for all other buildings.Before setting the valve, ensure the hot water source is switched on and •supplying water within the specified hot water temperature limits. The recommended temperature differential hot supply/mixed outlet •temperature to ensure thermal shut off is 15°C.At a flow rate of not less than 4 litres/minute, allow the water to flow •1-2 minutes to ensure the mixed water temperature has stabilised. Using a thermometer, measure temperature at nearest outlet to •tempering valve . Using the adjusting tool supplied, rotate the adjusting spindle (H) hot •or (C) cold as indicated on the tool until the required set temperature is achieved .

set temperature adjustment

mixed flow

hot flow cold flow

non–return valve

thermal element

valve

cap

16

HIGH PERFORMANCE SOLAR TEMPERING VALVE

FEATURES

SPECIFICATIONS

PRODUCT CODES

NSTV20 High Performance Solar Tempering Valve

Provides safe controlled water temperature to •sanitary outletsCast DR brass body •Fail Safe: • Failure of cold water supply causes valve to close and shut off hot flowAdvanced polymers give greater resistance to •calcium depositsFactory tested and set at 55ºC adjustable from •35ºC to 58ºCIntegral Non-Returns on hot and cold - ideal for •commercial installationsTamper proof adjustment special tool supplied •Maximum Hot Inlet Temperature 99°C •

Conforms to: NZS4617:1989 •Connections: 20 mm (¾ BSP) male •Recommended outlet temperature range: 45°C to 55°C • (2)

Factory setting (must be commissioned on site): 55°C nominal •Accuracy of mixed outlet temperature: ± 3°C •Cold water supply: 5°C to 25°C •Hot water supply: 60°C to 99°C • (1)

Hot water / mixed water temperature differential: 15°C minimum •Supply pressure – static: 1600 kPa maximum •Supply pressure – dynamic: 200 kPa minimum • 500 kPa maximum •Max permitted pressure variations at either inlet: ± 10% maximum • (4,5)

(from supply pressure at commissioning)Pressure supply differential – dynamic : 3:1 maximum • (3)

(at time of commissioning)Minimum flow rate: 4 litres/minute •

Notes:The Building Code Approved Document G12 clause 6.14 states that water shall be stored at not less 1) than 60°C to inhibit the growth of legionella bacteria. To obtain good tempering valve response the cylinder thermostat should be set at a minimum of 65°C.The valve can be set as low as 35°C or as high as 58°C, depending on site conditions. (These 2) temperatures are outside the optimum working range of the valve and the requirements of G12).The maximum ratio permitted between supply pressures, under dynamic flow operation. It is recom-3) mended at time of commissioning that hot and cold pressures be as equal as possible .The maximum permitted pressure variation in either supply from commissioning pressures in order 4) to maintain the outlet temperature to ±3°C.Note: Steps should be taken to eliminate any causes of rapid changes in supply pressures, as this 5) may result in an outlet temperature spike greater than ±3°C from commissioned temperature. If a spike occurs it may take a few seconds for the temperature to stabilise back to within ±3°C.

17

HIGH PERFORMANCE SOLAR TEMPERING VALVE

INSTALLATION

IMPORTANT

Fig 6.

Do not install an NMTV directly onto a hot water cylinder. It is •recommended that the valve be installed as close to the hot water source as possible. For optimum performance install with a 150mm thermosyphon between the cylinder outlet and hot inlet. (Refer Fig 10. Page 25).If installed at an outlet fixture, 1m of pipe must be installed between the •NMTV and the outlet.Strainers are essential to prevent debris entering the NMTV that could •prevent it working effectively. All NMTV installations should have line strainers fitted. It is recommended that a NEFA NPC500 valve (with filter/strainer) is installed upstream of the cold inlet.


Tempering valves must be commissioned at time of installation. The delivered hot water temperature at any sanitary fixture used for •personal hygiene shall not exceed:a) 45°C for early childhood centres, schools, old people’s homes, institutions for people with psychiatric or physical disabilities, hospitals, andb) 55°C for all other buildings.Before setting the valve, ensure the hot water source is switched on and •supplying water within the specified hot water temperature limits. The recommended temperature differential hot supply/mixed outlet •temperature to ensure thermal shut off is 15°C.At a flow rate of not less than 4 litres/minute, allow the water to flow •1-2 minutes to ensure the mixed water temperature has stabilised. Using a thermometer, measure temperature at nearest outlet to •tempering valve . Using the adjusting tool supplied, rotate the adjusting spindle (H) hot •or (C) cold as indicated on the tool until the required set temperature is achieved .

Filter & Non-return

Mixed outlet

Cold inlet

Hot inlet

Valve member

Thermostatic element

Temperature adjustment

18

COLD WATER EXPANSION VALVE

FEATURES

SPECIFICATIONS

PRODUCT CODES

Forged Dezincification Resistant (DR) •brass bodyStainless steel valve seat standard •Incorporates an outlet port for •running direct equal pressure cold supply to TLVDesign of valve allows •perfect washer contact maintaining excellent seating at low relief pressure settingsDiaphragm sealed spring •chamber eliminates O-ring drag associated with normal piston type sealingIntegral non-return valve supplied to conform to NZBC G12 •Serviceable •Easy to operate flushing mechanism •Valve can be used as cylinder drain •Complies with the requirements of NZBC G12 •

Conforms to NZS:4608 •Connections: • Inlet, Outlet and TLV Outlet 20 mm (¾ BSP) male Drain 15 mm (½ BSP) maleFactory set for 7.6 m head and 850 kPa systems •Valve seat stainless steel •

NECWE76 76 kPa NEFA Cold Water Expansion ValveNECWE700 700 kPa NEFA Cold Water Expansion Valve

19

COLD WATER EXPANSION VALVE

INSTALLATION

IMPORTANT

Fig 7.

The drain line must not rise above the NEFA CWE Valve. It should •run at a down grade out to atmosphere, to a point where the outlet cannot be obstructed or blocked and where expansion, or other vented water will not cause a hazard or a nuisance . It should not exceed 9m in length and include not more than three 90° bends.Observe flow direction on body. •


The NEFA CWE Valve is factory set to relieve at a pressure slightly •less than the NEFA Pressure Relief Valve and is not field adjustable.For low pressure systems the NEFA Pressure Reducing Feed Valve •setting must be reduced 1½ turns to avoid water wastage.For mains pressure systems a NEFA Pressure Limiting Valve must be •fitted if the cold supply pressure is greater than 500 kPa.

drain connection

stainless steel valve seat

manual flush control

integral non–return

tempering valve connection(not shown)

diaphragm sealeddry spring chamber

20

15mm 3-in-1 FILTER STOPCOCK& NON-RETURN VALVE

FEATURES

SPECIFICATIONS

PRODUCT CODES

Forged Dezincification Resistant (DR) •brass bodyPrevents damage to water system by •filtering foreign particlesFilter can be cleaned without shutting off •any other valve60 mesh stainless steel filter ensures •efficient capture of foreign particlesBuilt-in non-return valve prevents back-flow •

N311 NEFA 15mm 3-in-1 Filter Stopcock & Non-return Valve

Connections: • Inlet 15 mm (½ BSP) male Outlet 15 mm (½ BSP) female Length 75 mm •Height 110 mm •60 mesh stainless steel filter •Maximum inlet pressure 2000 kPa •

21


INSTALLATION

IMPORTANT

SERVICING

Fig 8.

Install at inlet to household system to protect the complete •household .Install the valve with flow in the direction as marked on the valve. •The NEFA 15mm 3-in-1 valve should be fitted with hand wheel down •to allow foreign particles to fall away when the filter is removed.The valve should not be installed in the ground or in situation where •it could be subject to freezing.The valve should be installed where it can be easily accessed. •

To ensure full flow through the valve it is recommended that the •filter should be removed and cleaned every 12 months, depending on the water supply.

To remove and clean filter (Refer Fig 8.):• Turn handle in clockwise direction and firmly shut off inlet 1 . water to valve .Remove handle retaining screw and remove hand wheel from 2 . spindle .Unscrew filter cover anticlockwise and remove by sliding off 3 . spindle .Remove filter and clean.4 . Reassemble in the reverse order .5 .

handle

spindle

cover

filter

non–return flap

22


FEATURES

SPECIFICATIONS

PRODUCT CODES

Forged Dezincification Resistant (DR) •brass bodyPrevents damage to water system • by filtering foreign particlesFilter can be cleaned • without shutting off any other valve60 mesh stainless steel • filter ensures efficient capture of foreign particlesBuilt in non-return valve prevents • back-flowDesign allows high flow rate • through valve

NE31120 NEFA 20mm 3in1 Filter Stopcock & Non-return Valve

Connections: • Inlet 20 mm (¾ BSP) male Outlet 20 mm (¾ BSP) female

Length 90 mm• Height 100 mm• 60 mesh stainless steel filter• Maximum inlet pressure 2000 kPa• Flow rate at 700 kPa inlet pressure: 125 l/min•

23


INSTALLATION

IMPORTANT

SERVICING

Fig 9.

Install at inlet to household system to protect the complete • household .Install the valve with flow in the direction as marked on the valve.• The NEFA 20mm 3-in-1 valve should be fitted with the filter cap • down to allow foreign particles to fall away when the filter is removed for cleaning .The valve should not be installed in the ground or in situation • where it could be subject to freezing.The valve should be installed where it can be easily accessed.•

To ensure full flow through the valve it is recommended that the • filter should be removed and cleaned every 12 months, depending on the water supply.

To remove and clean filter (Refer Fig 9.):• Turn handle clockwise to shut off inlet water to valve.1 . Unscrew filter cap anticlockwise and remove from valve body.2 . Withdraw filter element and clean.3 . Reassemble in the reverse order taking care not to damage 4 . filter.

Note the filter cover only needs to be hand tight as it is o-ring sealed.

cap

filter

non–return valve

handle

24

INSTALLATION GUIDELINES

INSTALLATION CHECKLIST

ALWAYS

NEVER

THIS BOOKLET IS ISSUED AS A GENERAL GUIDE ONLYRefer to the water heater manufacturer’s installation instructions for specific requirements.Installation of valves should always be carried out by a qualified plumber and must comply with the requirements of the New Zealand Building Code and local Territorial Authority. Refer to the New Zealand Building Code Compliance Document G12 Water Supplies available from the Department of Building and Housing .If you have any questions please contact Methven LimitedCustomer Service free phone 0800 804 222

Always connect NEFA valves to water heaters with non-ferrous •fittings and copper pipe.Always use copper pipe for drain lines from relief valves and cold •water expansion valves .Always check water supply pressure with a pressure gauge. •Always flush pipes before connecting valves. •Always check for the correct flow direction through valves as •indicated by markings on the valve and fitting instructions.Always ensure that there is access to the hot water cylinder and •valving in case future adjustment or replacement is required.Measure delivered hot water temperature with thermometer at •sanitary outlets.

Never install a tempering valve directly onto the outlet of the hot •water cylinder.Never attempt to adjust valves or tamper with seals, except as •directed in instruction sheets .Never attempt to adjust the setting of pressure relief, temperature •pressure relief or cold water expansion valves .Never fit a stop valve or any obstruction in the piping between the •connection from the hot water cylinder and the inlet of a Pressure Relief Valve .Never fit a stop valve or any obstruction in a pressure relief or cold •water expansion drain line .Never expose valves to a naked flame or heat. Heat will destroy the •seals and the sealing parts of the valve .Never allow thread sealing tape to extend over the end of threads, •excess tape may be cut free when making connections and affect the function of the valve .

25


REMEMBER

MAINS PRESSURE

Fig 10.

Faulty valves must be immediately repaired or replaced. •These are safety devices and must be in excellent working order. •

Always install a NEFA NPC500 Mains Pressure Inlet Control Valve in •the main water supply at point of entry. This will provide a point of isolation, a filtered water supply and balanced water pressure to the whole house .NEFA Cold Water Expansion Valve drain lines should not exceed 3m •in length and include not more than three 90º bends.For optimum performance the cold water supply to the NEFA •tempering valve must be at the same pressure as the hot water supply from the cylinder to the tempering valve. The NEFA Cold Water Expansion Valve has an outlet port to allow a simple connection to the tempering valve. Use 20mm copper pipe to make up hot and cold supply connections to the tempering valve. In order to ensure that the NEFA tempering valve works efficiently set the hot water cylinder thermostat to between 65°C to 70°C.Where separate hot and cold water supplies are delivered to the •NEFA tempering valve ensure the pressures are balanced and a non-return valve is fitted to the hot water supply.With average domestic hot water usage 2 to 4 litres of water from •thermal expansion can be expected .

MAINS PRESSURE INSTALLATION

NEFA NPC500 MAINS PRESSURE INLET CONTROL WITH INTEGRAL ISOLATION & FILTER

NEFA NECWE700 COLD WATER EXPANSION

VALVE WITH NON-RETURN

BALL VALVE

NEFA NMTV MAINS PRESSURE TEMPERING VALVE

TPR VALVE

DRAIN

DRAIN

COLD WATER MAINS INLET

MAINS PRESSURE STORAGE

WATER HEATER

HOT WATER TO LAUNDRY & KITCHEN

TEMPERED WATER TO BATHROOM AND SHOWER

BALANCED PRESSURE COLD WATER TO HOUSEHOLD

150mm Recommended

26


LOW PRESSURE — VALVE VENTED

Fig 11.

Always install a NEFA 3-in-1 Filter Stopcock in the main water •supply at point of entry. This will protect the whole house and make isolation easy for servicing.

PRESSURE REDUCING FEED VALVENEFA Pressure Reducing Feed Valves come factory set at 3.7 m, 7.6 m •or 12.2 m as indicated on the valve.The valve will operate in any position but for ease of service the •valve should be installed with the cap up .In low pressure installations with a NEFA Cold Water Expansion •Valve the NEFA Pressure Reducing Feed Valve adjusting screw must be turned 1½ turns anticlockwise to avoid water wastage.When installed on a side entry cylinder a thermosyphon loop of •150mm at the entry to the cylinder will help prolong the life of the NEFA Pressure Reducing Feed Valve.When set at the factory, allowance is made for the NEFA Relief Valve •to be fitted 1 m above the NEFA Feed Valve. If they are installed level as in under sink heaters undo lock nut and turn adjustment screw 1½ turns anticlockwise.

LOW PRESSURE — VALVE VENTED INSTALLATION

NEFA NECWE76 COLD WATER EXPANSION

VALVE WITH NON-RETURN

NEFA NFV7615 PRESSURE REDUCING FEED VALVE

NEFA N311 3in1 FILTER STOPCOCK & NON-RETURN

NEFA NRV76 PRESSURE & VACUUM RELIEF VALVE

BALL VALVE

NEFA NTLV TEMPERING VALVE

DRAIN

DRAIN

CYLINDER DRAIN

ALT SIDE ENTRY




80m

m M

IN

WATER HEATER TO

NZS 4602 WITH

THERMOSTAT &

THERMAL ENERGY CUT OUT

27


SETTING THE OUTLET PRESSURE OF NEFA FEED VALVE

Switch off the power to the Hot Water Cylinder. •Run a hot tap for 5-10 seconds. This eliminates any thermal •expansion in the water heater .For open vented systems observe the vent pipe. •For systems with a NEFA Relief Valve observe the outlet from the •drain .For systems with a NEFA Cold Water Expansion Valve observe the •drain from the Cold Water Expansion Valve .Release the lock nut on the adjusting screw of the NEFA Feed Valve •and wind the adjusting screw clockwise to increase the outlet pressure until water is observed at the vent .Slowly reduce the outlet pressure from the pressure reducing valve •by turning adjusting screw anticlockwise until water from vent stops.When water has stopped the pressure from the outlet of the NEFA •Feed Valve is now balanced at the pressure of the relief or vent . For the system to be efficient and to avoid wastage there must be a differential between the venting pressure and the NEFA Feed Valve’s set outlet pressure.Wind the adjusting screw of the NEFA Feed Valve a further ½ to ¾ •turn anticlockwise.

SERVICING THE JUMPER WASHER OF NEFA FEED VALVE

Isolate water supply •to valve at inlet and outlet .Remove cap by •unscrewing from valve body.Remove bridge by •sliding out of fork.Lift off jumper valve and •remove jumper washer.Inspect jumper valve •and valve seat on jet for damage .Jet is sealed by o-ring •and can be unscrewed from body.Replace defective parts •and reassemble .Restore water pressure •and reset outlet pressure of feed valve . + cwccw -

cap

jumper valve

fork

bridge

adjusting screw

lock nut

jumper washer

Fig 12.

28


LOW PRESSURE — OPEN VENTED

Fig 14.

Fig 13.

In areas subject to freezing vent pipes shall be insulated; NZBC G12 •Clause 7.2. The standing water level shall be a minimum of 300mm below insulation . The use of an expansion control valve can help protect the water •heater .

With low pressure header tank installations the NEFA tempering •valve requires a minimum of 2.5m head and for best performance install the NEFA tempering valve as close to the base of the cylinder as possible using 20mm copper pipe.

LOW PRESSURE — OPEN VENTED INSTALLATION

NEFA NFV7615 PRESSURE REDUCING FEED VALVE

NEFA N311 3in1 FILTER STOPCOCK & NON-RETURN BALL VALVE


VENT PIPE

ROOF LINE

CYLINDER DRAIN

ALT SIDE ENTRY


WATER HEATER TO

NZS 4602 WITH

THERMOSTAT &



7.6 METRES MAX. 3.7 METRES MIN. NOT TO EXCEED

WORKING PRESSSURE STATED ON CYLINDER.


LOW PRESSURE — HEADER TANK INSTALLATION

NEFA N311 3in1 FILTER STOPCOCK & NON-RETURN

BALL VALVE


VENT PIPE

ROOF LINE

CYLINDER DRAIN

ALT SIDE ENTRY


7.6 METRES MAX. 3.7 METRES MIN. NOT TO EXCEED

WORKING PRESSSURE STATED ON CYLINDER.


BALANCED PRESSURE COLD WATER TO SHOWER

HIGH PRESSURE COLD WATER TO HOUSEHOLD

2.5 METRES MIN HEAD REQUIRED AT TEMPERING VALVE


WATER HEATER TO

NZS 4602 WITH

THERMOSTAT &


29


PRESSURE RELIEF VALVESNEFA Pressure Relief Valves •are factory set to 3.7 m 7.6 m or 12.2 m head as indicated on the valve and cannot be adjusted.Relief valves must only be •installed on a thermostatically controlled hot water cylinder with a maximum heating capacity of 8 kW.Relief Valves must not be •fitted to a water heater with a wetback or where solar heating is used .To protect the NEFA Relief Valve from excessive heat we recommend •that the relief valve is fitted 80 mm below the top of the cylinder as shown in Fig 11. Alternatively install the NEFA Relief Valve after a thermosyphon loop of a minimum of 80 mm as shown in Fig 15.The NEFA Relief Valve should not be fitted more than 300mm above •the cylinder. Except as detailed under existing installations below.Drain lines from the NEFA Cold Water Expansion Valve and the NEFA •Relief Valve must fall continuously from the outlet of the valves. Drain lines should not exceed 3m in length and include not more than three 90° bends.Drain lines should run to a point where the outlet cannot be •obstructed or blocked and where expansion and other vented water is discharged to atmosphere and will not cause a hazard or a nuisance . If there is a possibility of the drain freezing, an air break in the drain •at the water heater is required .With average domestic hot •water usage 2 to 4 litres of water from thermal expansion can be expected .To increase the pressure of an •existing installation with an open vent to the roof, a NEFA 3.7 m Relief Valve can be fitted to the vent not more than 3.7 m above the bottom of the cylinder as shown in FIG 16. The pressure reducing valve •should then be adjusted, refer Fig 12 Page 27.The vent pipe must be bent as •shown so that the outlet of the NEFA Relief Valve points down. This installation is not suitable for areas subject to freezing.

ALTERNATIVE RELIEF VALVE INSTALLATION

80 mm MIN

NEFA NRV76PRESSURE & VACUUM RELIEF VALVE

INSTALL WITH INTEGRAL VACUUM BREAK VENT HOLE UP

DRAIN

Fig 15.

WATER HEATERTO

NZS 4602WITH

THERMOSTAT&

THERMAL ENERGYCUT OUT

EXISTING INSTALLATION

ROOF LINE

NEFA NRV37PRESSURE & VACUUM RELIEF VALVE

3.7 METRES MAX.HEIGHT FROM

CYLINDER BASE

TOTAL HEADVENT + RELIEF VALVE

NOT TO EXCEEDWORKING PRESSSURESTATED ON CYLINDER

Fig 16.

WATER HEATERTO

NZS 4602WITH

THERMOSTAT&

THERMAL ENERGYCUT OUT

30

TROUBLESHOOTING GUIDE

FAULT FINDING FOR HOT WATER INSTALLATIONS

NO

If the Relief valve drain drips.

YES

YES

YES

NO

NO

NO

YES

YES

NO

High Pressure Low Pressure

DripGush

Is a Cold Water ExpansionValve (CWE) fitted?

Install CWE withcorrect pressure

Check correct pressureCWE is fitted

Check CWE drain line isnot blocked

Unblock CWE drainline

Has Relief Valve stoppeddripping?

CHECK RELIEF VALVE

Does the TemperaturePressure Relief Valve(TPR) drip or ‘gush’

intermittently

Turn off water supply tohot water cylinder.

Dismantle the Relief Valveand clean. Check seat,

washer and diaphragmfor damage.

Replace if necessary.Refit Relief Valve.

Turn water on.Note: Due to factory

settings, springs cannotbe exchanged.

CheckThermostat.

TPR isrelieving hightemperature

water.

ReplaceTPR

If the Cold Water Expansion Valve(CWE) drain or vent pipe drips.

Check for thermal expansion.Turn water heater energy supply off.

Run hot tap for 5-10 seconds.

Has dripping stopped?

Drip is normal thermal expansion.Check thermostat is not set to high.Average domestic hot water useage

can expect 2-4 liters of expansionwater per day.

Nefa Feed, CWE and ReliefValves are OK. Turn waterheater energy supply on.

31

TROUBLESHOOTING GUIDE

NO

If the Relief valve drain drips.

YES

YES

YES

NO

NO

NO

YES

YES

NO


DripGush

Is a Cold Water ExpansionValve (CWE) fitted?

Install CWE withcorrect pressure

Check correct pressureCWE is fitted

Check CWE drain line isnot blocked

Unblock CWE drainline

Has Relief Valve stoppeddripping?

CHECK RELIEF VALVE

Does the TemperaturePressure Relief Valve(TPR) drip or ‘gush’

intermittently

Turn off water supply tohot water cylinder.

Dismantle the Relief Valveand clean. Check seat,

washer and diaphragmfor damage.

Replace if necessary.Refit Relief Valve.

Turn water on.Note: Due to factory

settings, springs cannotbe exchanged.

CheckThermostat.

TPR isrelieving hightemperature

water.

ReplaceTPR

If the Cold Water Expansion Valve(CWE) drain or vent pipe drips.

Check for thermal expansion.Turn water heater energy supply off.

Run hot tap for 5-10 seconds.


Drip is normal thermal expansion.Check thermostat is not set to high.Average domestic hot water useage

can expect 2-4 liters of expansionwater per day.

Nefa Feed, CWE and ReliefValves are OK. Turn waterheater energy supply on.

CHECK SUPPLY PRESSURE

YES

NO


NO YES

NO

NO

YES

YES

Check for cross feeding.Turn off water supply to the hot

water cylinder only.


Check and rectify any crossfeeding (inadvertent high pressure

connection to low pressure) througha mixing unit e.g. shower mixer,single lever mixer etc. Turn water

back on. Note: Cold feed to TLVmust come off cold cylinder feedpipe AFTER the feed valve or PLV.

Remove the Feed Valvecap. Check jet, seat and

washer for damage.Replace if necessary.Turn water back on.

Is a Pressure LimitingValve (PLV) fitted?

Installcorrect PLV

ReplacePLV



Check CWETurn off water supply to the hot water cylinder. Dismantle the

CWE and clean. Check seat, washer and diaphragm for damage.Replace with CWE kit if necessary. Turn water on.Note: CWE is factory set and cannot be adjusted.

Check Feed Valve setting matches CWE / vent pipe height.(Low pressure systems only.) Refer setting instructions.

32

MAINS PRESSURE

MAINS PRESSURE INSTALLATION PACK

500 kPa 20 mm

NPC500 Mains Pressure Inlet Control Valve (Pressure Limiting, Isolation & Filter)

NMTV Mains Pressure Tempering Valve

NECWE700 Cold Water Expansion Valve (with Intergral Non-Return)

BV78820 20 mm M&F Ball Valve

NEMPK

LOW PRESSURE INSTALLATION PACK

7.6 m Head

NFV7615 Pressure Reducing Feed Valve (7.6 m)

NRV76 Pressure Relief Valve (7.6m) (With Integral Vacuum Break)

NECWE76 Cold Water Expansion Valve (7.6 m) (with Intergral Non-Return)

NTLV Temperature Limiting Valve

N311 Filter, Stop cock & Non-return


NVKLP

VALVE PACKS

LOW PRESSURE

33

MAINS PRESSURE SOLAR INSTALLATION PACK

500 kPa 20 mm

NPC500 Mains Pressure Inlet Control Valve (Pressure Limiting, Isolation & Filter)

NSTV20 High Performance Solar Tempering Valve

NECWE700 Cold Water Expansion Valve (with Intergral Non-Return)


NMPKSOL

MEDIUM PRESSURE INSTALLATION PACK

12.2m Head

NFV12215 Pressure Reducing Feed Valve (12.2 m)

NRV122 Pressure Relief Valve (12.2m) (With Integral Vacuum Break)

NECWE120 Cold Water Expansion Valve (12 m) (with Intergral Non-Return)

NTLV Temperature Limiting Valve

N311 Filter, Stop cock & Non-return


NVK122

MAINS PRESSURE

MEDIUM PRESSURE

VALVE PACKS

34

NEFA SPARE PARTS & SERVICE KITS

SPARE PARTS & SERVICE KITS

PRESSURE REDUCING FEED VALVESPNFVSK Nefa Feed Valve Service KitNFVW Nefa Feed Valve Silicon Washer (pack 20)920606 Nefa Feed Valve Jumper AssemblyNFVD Nefa Feed Valve Diaphragm920533 Nefa Feed Valve Diaphragm Assembly with Screw and Nut920541 Nefa Feed Valve Fork920568 Nefa Feed Valve Fork BridgeNFVCJ Nefa Feed Valve Replacement Jet Kit920607 Nefa Feed Valve Plastic Cap and O-ring920509 Nefa Feed Valve Cap O-ring (pack 5)920657 Nefa Feed Valve Spring 3.7m and 7.6m920665 Nefa Feed Valve Spring 12.2m270031 Nefa Feed Valve Adjusting Screw and Nut920495 Nefa Feed Valve Backing Plate920673 Nefa Feed Valve Spring Cap

PRESSURE AND VACUUM RELIEF VALVESPNRVSK Nefa Relief Valve Service KitNRVD Nefa Relief Valve Diaphragm AssemblyNRVF Nefa Relief Valve Flap

15mm 3-in-1 FILTER STOPCOCKSP193113 Nefa Filter 311 15mmSP311FLAP Non-return Flap N311 15mm786101 311 15mm Spindle O-ringSP31120SK Nefa Kit 20mm 3-in-1

NTLV TEMPERATURE LIMITING VALVE782004 Nefa TLV Service Kit

NPC500 MAINS PRESSURE INLET CONTROL VALVE920700 Filter and O-ring Service Kit

NON-RETURNNECWENRV Nefa CWE Non-return Valve and Holder

SPARE PARTS & SERVICE KITS

www.methven.comFreecall: 0800 804 222 Freefax: 0800 805 222

Please note: While every effort is made to ensure that the details in this brochure were correct at the time of printing, Methven reserves the right to alter specifications or product from that shown.

This brochure is printed on an environmentally responsible paper, elemental chlorine free. Printed with soy-based printing inks.

For detailed technical and warranty information, please visit www .methven .com .

METHVEN LIMITED447 Rosebank Road, Private Bag 19996, Avondale, Auckland 1026, New Zealand, Telephone +64 9 829 0429, Facsimile +64 9 829 0439, Email info@methven .net

280101 Issue D May 2011

methven nefa pressure reducing valves reference

Documents

nefa pressure

mains pressure tempering

nefa valve packs

maximum inlet pressure

nefa valves

vacuum relief valve

installation of nefa

cold water expansion