WILKINS

Principles OfPressure

Regulationwith Performance Curves

For Wilkins Pressure Regulators

P e r f o r m a n c e U n d e r P r e s s u r e

the need toCONSERVE NATURAL

RESOURCES

,

NR3NR3XL

500XL500

500XLYSBR500YSBR

600600XL7070XL

MODEL ASSE IAPMO CSA

1/2" - 1" 1/2" - 1" 1/2" - 1"

❍

❍

❍4

2

1

FLOW ➞

Model NR3�

❍3

regulator, the o-ring is pushed into the narrow section of the gland by incom-

ing water pressure and seals tight. In the event that the pressure on the

downstream side of the regulator becomes equal to the incoming pressure, the

o-ring will slide to the wide section of the gland and sealing can no longer be

facilitated. When this action occurs, equilibrium will be maintained and the

downstream pressure will never become greater than the upstream pressure.

This will prevent the downstream pressure from rising to the Temperature

& Pressure Relief Valve opening point, (usually 150 psi). It must be noted

that the By-pass feature will not work in applications that have a Backflow

Preventer in the incoming water line or if the incoming pressure is greater

than the Temperature & Pressure Relief Valve opening point. Should these

conditions be present in the system, a Thermal Expansion Tank (Wilkins

XT series) would be the proper means of controlling the elevated pressure

downstream of the regulator.

❍5

WILKINS

WILKINS is the one name that is synonymous with quality in the manufacture of Pressure Reducing Valves for water. Specialists in the production of Pressure Reducing Valves, WILKINS test every valve under conditions far more severe than will ever be encountered in the field. This is your assurance that when you buy, specify or install WILKINS Pressure Reducing Valves you are selecting the most reliable regulator in the industry.

WILKINS is the acknowledged leader in today’s market in creating technical ad-vances to produce a product consistent with the needs of every facet of our industry. WILKINS Pressure Reducing Valves are made to meet the exact needs of residential, commercial, industrial, fire protection, irrigation and marine applications.

Features Include:

ALL BRONZE CONSTRUCTION. By using an all bronze construction the potential for electrolytic corrosion is eliminated. Electrolytic corrosion occurs when two dissimilar metals are joined and react to each other (Model NR3 utilizes a composite bell). The XL models are constructed of lead-free bronze and contain a weighted average lead content less than 0.25% for wetted surfaces.

THREADED CONNECTION OF BELL HOUSING TO BODY. Provides easier access to the spring, diaphragm, screen or plunger if service is needed. Eliminates screws that can corrode.

HEX ON BELL. Provides greater flexibility in installation and access without special tools.

STAINLESS STEEL SCREEN. Provides a long-wearing material to eliminate fouling.

NYLON REINFORCED BUNA-N DIAPHRAGM. Provides superior strength.

STAINLESS STEEL OR COMPOSITE SEAT. Provides greater resistance and durability, over a long period of time, to wear caused by wire drawing.

PATENTED O-RING BYPASS. Bypass prevents a closed system. Helps eliminate the problems associated with thermal expansion. The WILKINS bypass meets and exceeds the requirements of A.S.S.E.

UNION END. A union end connection is available on all WILKINS regulators through 2”. Some regulators are available with unions on both ends.

COMPLIES with all major code agencies including the Uniform Plumbing Code, National Plumbing Code, Federal Housing Administration, American Society of Sanitary Engineers, Canadian Standards Association and major city codes.

EVERY VALVE IS HYDROSTATICALLY TESTED at the factory under condi-tions far more severe than the valve will see in service. Each valve is tested at the extreme end of the spring range and factory set.

ORIENTATION. Can be installed in both bell up or bell down orientation.

NR3(1 1/4”, 1 1/2” & 2”)

NR3(1/2”, 3/4” & 1”)

NR3 (1/2", 3/4" &1")

NR3(1 1/4”, 1 1/2” & 2”)

NR3(1/2”, 3/4” & 1”)

NR3 (1 1/4", 1 1/2" & 2")

WILKINS

1/2" 500 TO HANDLE LOW�DEMANDS (SET @ 70 PSI)

REDUCED�PRESSURE(OUTLET)

HIGH�PRESSURE�(INLET)

1" 500 TO HANDLE MEDIUM�DEMANDS (SET @ 65 PSI)

2" 500 TO HANDLE HIGH�DEMANDS (SET @ 60 PSI)DIRECTION OF FLOW

DIRE

CTIO

N O

F FL

OW

MODEL�500HR

MODEL�500

200 psi

50 psi

125 psi

DIRECTION OF FLOW

DIRECTION OF FLOW

WATERMETER

MODEL 850BALL VALVE

MODELNR3

HOSE BIBB

MODEL BFP-9HOSE BIBB

VACUUM BREAKER

"S"STRAINER

valveSELECTION

AND SIZING The selection of the correct type of regulator depends entirely on the

accuracy of the regulation required.

The Best WayThe only truly sound valve selection procedure to follow is to capacity size a valve

on the basis of known performance data related to system requirements. The

amount of water that a regulator must flow is determined by the flow required

for the valve application in gallons per minute, and the required delivery pres-

sure in psi. Additionally, the tolerable Fall-off that the system can withstand

must be considered.

Reduced pressure change that occurs when a valve opens is known as Fall-off.

Reduced Pressure Fall-off is the difference between the static pressure and the

residual or flowing pressure downstream of the regulator. Fall-off is an inherent

characteristic of all direct acting regulators and is an important factor when

selecting the proper valve size and type. Fall-off is used to predict the valve

capacity in Gallons per Minute.

By putting this data together it can be seen that three pieces of information are

needed to properly size a regulator. These pieces of information are:

· Flow required for the application in Gallons per Minute (GPM)

· Delivery pressure of the water in Pounds per Square Inch (PSI)

· The maximum allowable difference between downstream flowing pressure

and static pressure or the Fall-off.

The Other WaysSome installers/designers may think they are doing their client a favor by

over-sizing the valve but this is simply not true. For example, using a 2" valve

because it will be twice as good as using a 1" valve, will lead to rapid failure of

the 2" valve. The valve plunger in oversized valves tends to remain close to the

seat in low flow conditions, causing wire draw and excessive wear. Under sizing

the regulator can have the same consequences. Under sizing causes very high

flowing velocity, which will cause noise and wear of the internal components.

Capacity rating of a pressure reducing valve is usually expressed in terms of

some single value. This value, to be useful, must specify all the conditions under

which the rating was established, otherwise it is impossible to factually adapt

it to system conditions. Set pressure and allowable reduced pressure fall-off

of 15 to 17 psi is considered reasonable for the average residential installation

and, in well designed valves, will produce a good rating. For Commercial and

Industrial applications, allowable Fall-off is usually much more critical. There-

fore, a standard allowable Fall-off cannot be given. It must be reviewed on a

case by case basis.

NR3

WILKINS

If, however, the inlet pressure to the pressure regulator is greater than or equal to

150 PSI , the Temperature & Pressure Relief Valve will discharge into the atmo-

sphere before the integral by-pass will operate.

The SolutionWilkins has several simple solutions to the Thermal Expansion problem.

The first is to install a Relief Valve for the control of Thermal Expansion in the

plumbing system. From the Wilkins Models P1520 and P1550 fixed setting Pressure

Relief Valves to the Model BVEC Water Heater Shut-Off Valve with integral Thermal

Expansion Relief Valve. The Model BVEC is a Full Port Bronze Ball Valve designed

for residential water heater applications where a water heater shut-off and thermal

expansion relief valve are combined to provide protection from thermal expansion.

Because the BVEC thermal expansion relief valve is designed to relieve pressure

periodically as the water heats, it will discharge approximately 1/3 of a gallon of

water (on a 40 gallon water heater) during a reheat cycle. While effective, the

disadvantage of using the BVEC is that a discharge line must be connected to the

relief valve outlet and directed to a safe disposal drain.

400WOG

BVEC

WILKINS

400WOG

WXTP 50V - 320V XT8 - XT35

WILKINS DIVISION

WXTPTHERMAL EXPANSION TANKFOR DOMESTIC HOT WATER SYSTEMS

WILKINS DIVISION

XTTHERMAL EXPANSION TANKFOR DOMESTIC HOT WATER SYSTEMS

A better solution to thermal expansion is to install a Wilkins Thermal

Expansion Tank to the plumbing system. The use of a water Thermal

Expansion Tank (WILKINS Model XT) is to accommodate the ad-

ditional water volume and prevent discharge from the Temperature

& Pressure Relief Valve. The Thermal Expansion Tank accepts the

expanded volume of water until it can be utilized back into the

system. As water temperature rises in the water heater,

expanded water enters the Thermal Expansion Tank’s water

reservoir. The pre charged air chamber absorbs the pressure

increase, maintaining system pressure at a point below the

Temperature & Pressure Relief Valve opening point. When

water is used, the pressure in the air chamber forces the

water back into the system until it once again equals the

supply pressure.

Selecting a properly sized Thermal Expansion Tank is criti-

cal in the reduction of pressure fluctuations in the system

and is determined by both supply pressure and water heater

capacity. The tank must be installed in the cold water supply side

between the backflow preventer or the pressure regulating valve

and the hot water heater.

Installation of the thermal expansion tank has proven to be

the most effective coded solution for the problem of thermal

expansion.

MODEL ZW1017AQUA-GARD TEMPERINGMIXING VALVE

HOSE BIBBVACUUM BREAKER

MODEL BFP-9

WATER METER

MODEL XTEXPANSION TANK

WATER HEATER

MODEL TP1100AT & P RELIEF VALVE

MODEL 850SHUT-OFF

REGULATORMODEL NR3

MODEL 195HOSE BIBB

SAFE DRAIN

WILKINS

COLD WATER

HOT WATER

Water Pressure Reducing Valve with Integral By-pass Check Valve• Maximum working water pressure 400psi• Reduced pressure range 15 to 75psi, factory set to 50psi• Includes corrosion-resistant drop-in acetal replacement cartridge with integral stainless steel strainer• Repair kits readily available

Water Pressure Reducing Valve with Integral By-pass Check Valve• Maximum working pressure 300psi• Spring range gives downstream adjustment capability of 25-75psi, factory set at 50psi• All bronze body

Lead-Free Water Pressure Reducing Valve with Integral By-pass Check Valve• Sizes: 1/2” - 2”• Contains weighted average lead content of less than 0.25%• Certified to NSF/ANSI 61-G

Water Pressure Reducing Valve with Integral By-pass Check Valve• Sizes 1/2”, 3/4”, 1”, 1 1/4”, 1 1/2”, 2”• Pressure rated at 300psi• Replaceable cartridge (1/2”, 3/4”, 1”) reduces time involved with cleaning and maintenance• The direct acting integral by-pass design prevents buildup of excessive system pressure caused by thermal expansion.• 70XL certified to NSF/ANSI 61-G

Model NR31/2” - 1 1/4”

Model NR31 1/2”-2”

Model NR3XL*

Model 70/70XL*

SELECTING THE RIGHT WILKINS REGULATOR

Water Pressure Reducing Valve with Integral By-pass Check Valve• Sizes: 1/2” thru 3”• Reduced pressure range 25psi to 75psi, factory set at 50psi• Recommended for industrial water lines and commercial irrigation systems• High flow capacity• 500XL certified to NSF/ANSI 61-G

Water Pressure Reducing Valve with Integral By-pass Check Valve• All of the great features of the model 500, plus an in-line bronze “Y” type strainer with 20 mesh stainless steel screen• Recommended for commercial installa-tions where debris is prevalent in the water system

Water Pressure Reducing Valve with Flanged Connections• Sizes: 2", 2 1/2", 3"• Comes with flanged connections• Recommended for commercial and indus-trial applications• Spring range 25 to 75psi, factory set at 50psi• High flow capacity

Boiler Regulator with Quick Fill/Purge LeverSizes: 1/2”• Recommended for installation on hy-dronic heating systems to reduce the inlet pressures to a lower reduced pressure• Reduced pressure range 10psi to 25 psi, factory set at 15psi• CI - cast iron body & bell, BR - all bronze body and bell, equipped with a Quick Fill/Purge lever, capable of feeding and purging of boiler feed lines.• Built-in check valve maintains a positive seal which prevents reverse water flow

Water Pressure Reducing Valve• Sizes 3/4” , 1”•Pressure adjustment range (0-50psi) makes the Model 90 most suitable to drip irrigation systems requiring lower operating pressures

Model 600/600XL*

• Sizes: 1/2”, 3/4”, 1”, 1 1/4”, 1 1/2”, 2’• Recommended for residential and commercial appli-cations where easy accessibility to an internal strainer screen is necessary.• 600XL certified to NSF/ANSI 61-G

• Integral stainless steel strainer with separate access cover• Replaceable stainless steel seat• All internal parts corrosion-resistant

Water Pressure Reducing Valve with Integral By-pass Check Valve and Strainer

WILKINS

Model 500FC/500XLFC*

Model 500/500XL*

Model 80BR

Model 80CI

Model 500YSBR/500XLYSBR*

Model 90

*XL suffix designates Lead-Free model with a weighted average lead content less than 0.25% for wetted surfaces

SELECTING THE RIGHT WILKINS REGULATOR

LightResidential Commercial Commercial Industrial

FOR THE RIGHT APPLICATION

WILKINS

NR3/NR3XL 1-1/4”, 1 1/2", 2”

NR3/NR3XL 1/2”-1”, 1 1/4"

Model 70/70XL

Model 600/600XL

Model 500/500XL

Model 500YSBR/500XLYSBR

Model 80CI & 80BR

Model 90

Model 500FC/500XLFC

Model 600 1/2" thru 2" (STANDARD)

0 20 40 60 80 10005

15

20

FLOW RATES (U.S. GPM)

FALL

OFF

(U.S

. PSI

G)

1/2" 3/4" 1" 1¼" 1½" 2"

10

Model 600 1/2" thru 2" (STANDARD)

0 20 40 60 80 10005

15

20

FLOW RATES (U.S. GPM)

FALL

OFF

(U.S

. PSI

G)

1/2" 3/4" 1" 1¼" 1½" 2"

10

0

5

10

15

20

0 10 20 30 40FLOW RATES (GPM)

FALL

OFF

(PS

IG)

0

34

69

103

1380.0 0.6 1.3 1.9 2.5

FLOW RATES (l/s)

FALL

OFF

(kpa

)

0

5

10

15

20

0 10 20 30 40 50 60 70 80 90 100FLOW RATES (GPM)

FALL

OFF

(PS

IG)

0

34

69

103

1380.0 0.6 1.3 1.9 2.5 3.2 3.8 4.4 5.0 5.7 6.3

FLOW RATES (l/s)

FALL

OFF

(kpa

)2" (50mm)1-1/2" (40mm)1-1/4" (32mm)

1/2" (15mm) 3/4" (20mm)1" (25mm)

0

5

10

15

20

0 10 20 30 40FLOW RATES (GPM)

FALL

OFF

(PS

IG)

0

34

69

103

1380.0 0.6 1.3 1.9 2.5

FLOW RATES (l/s)

FALL

OFF

(kpa

)

0

5

10

15

20

0 10 20 30 40 50 60 70 80 90 100FLOW RATES (GPM)

FALL

OFF

(PS

IG)

0

34

69

103

1380.0 0.6 1.3 1.9 2.5 3.2 3.8 4.4 5.0 5.7 6.3

FLOW RATES (l/s)

FALL

OFF

(kpa

)2" (50mm)1-1/2" (40mm)1-1/4" (32mm)

1/2" (15mm) 3/4" (20mm)1" (25mm)

MO

DE

L N

R3*

1/2”, 3/4”, 1”

PERFORMANCE CURVES For Wilkins Pressure Regulators

MO

DE

L N

R3*

1 1/4", 1 1/2", 2"

1/2", 3/4", 1", 1 14", 1 1/2" , 2"

MO

DE

L 70

/70D

U*

FLOW RATES (GPM)

FALL

OFF

(PSI

G)

0

5

1015

0 40 80 120

69104

2.5 5.0 6.3

FALL

OFF

(kpa

)

FLOW RATES (l/s)

MODEL 70 1/2" THRU 2" (STANDARD & METRIC)

3/4" � (20mm)

35

20 1381/2" �

(15mm)1" �

(25mm) 1 1/4" �(32mm)

1 1/2" �(40mm)

2" �(50mm)

WILKINS

MO

DEL

80C

I &

80B

R

FLOW RATES (GPM)

SUPP

LY P

RESS

URE

(PSI

)

0

20

4060

51010 20

276414

6.03.0 1.3

SUPP

LY P

RESS

URE

(kpa)

FLOW RATES (l/s)

138

80 552

5

1.0 1/2" (15mm)

1/2"

* Includes XL Model

MO

DEL

90

3/4", 1" M

OD

EL 5

00* 1/2", 3/4",1",1 1/4",1 1/2", 2", 2 1/2", 3"

FLOW RATES (GPM)

FALL

OFF

(PSI

G)

0

5

1015

0 20 30 40

69104

0.6 1.3 2.5

FALL

OFF

(kpa

)

FLOW RATES (l/s)

MODEL 90 3/4" & 1" (STANDARD & METRIC)

35

20 138

10

1.9 3/4" (20mm)

1" (25mm)

FLOW RATES (GPM)

FALL

OFF

(PS

IG)

0

5

1015

0 100 200 300

69104

6.3 12.6 18.9

FALL

OFF

(kpa

)

FLOW RATES (l/s)

MODEL 500 1/2" THRU 3" (STANDARD & METRIC)

3/4" �(20mm)

35

20 1381/2" �

(15mm)1" �

(25mm) 1 1/4" �(32mm)

1 1/2" �(40mm)

2" �(50mm)

2 1/2" �(65mm)

3" �(80mm)

MO

DEL

500Y

SBR

*

1/2", 3/4, 1", 1 1/4", 1 1/2", 2", 2 1/2", 3"

FLOW RATES (GPM)

FALL

OFF

(PSI

G)

0

5

1015

0 100 200 300

69104

6.3 12.6 18.9

FALL

OFF

(kpa

)

FLOW RATES (l/s)

MODEL 500YSBR 1/2" THRU 3" (STANDARD & METRIC)

3/4" �(20mm)

35

20 1381/2" �

(15mm)1" �

(25mm) 1 1/4" �(32mm)

1 1/2" �(40mm)

2" �(50mm)

2 1/2" �(65mm)

3" �(80mm)

MO

DEL

500

FC*

& 5

00FC

BP*

2", 2 1/2", 3"

FLOW RATES (GPM)

FALL

OFF

(PSI

G)

0

5

1015

0 100 200 300

69104

6.3 12.6 18.9

FALL

OFF

(kpa

)

FLOW RATES (l/s)

MODEL 500FC 2" THRU 3" (STANDARD & METRIC)

35

20 138 2 1/2" (65mm) 2" (50mm) 3" (80mm)

WILKINS

* Includes XL Model

MO

DEL

600

* 1/2", 3/4, 1", 1 1/4", 1 1/2", 2"

FLOW RATES (GPM)

FALL

OFF

(PSI

G)

0

5

1015

0 40 80 120

69104

2.5 5.0 6.3

FALL

OFF

(kpa

)

FLOW RATES (l/s)

MODEL 600 1/2" THRU 2" (STANDARD & METRIC)

3/4" � (20mm)

35

20 1381/2" �

(15mm)1" �

(25mm) 1 1/4" �(32mm)

1 1/2" �(40mm)

2" �(50mm)

MO

DEL

600

DM 3/4"

FLOW RATES (GPM)

FALL

OFF

(PSIG

)

0

5

1015

0 20 30 40

69104

0.6 1.3 2.5

FALL

OFF

(kpa

)

FLOW RATES (l/s)

MODEL 600DM 3/4" (STANDARD & METRIC)

35

20 138

10

1.9

Pressure Regulators help in Water Conservation.

Reducing water pressure from 100 to 50 psi results in a

33% water savings and cuts wastewater by one third.

Water systems can be viewed like an electrical

system. Overhead transmission lines at the street carry

12,000 volts. This high voltage is sent through a trans-

former that reduces the voltage to 240v/120v. This is

done for safety and conservation purposes.

WILKINS

* Includes XL Model

TYPICAL INSTALLATIONS For Wilkins Pressure Regulators

Model NR3/NR3XL Model 70/70XL Model 70DU Model 600/600XL

Model 500/500XL/500FC/500XLFC

Model 500YSBR/ 500XLYSBR

Model 80 Model 90

PROTECTIVE�ENCLOSURE

DIRECTION OF FLOW

12" MIN.�30" MAX.

MODEL 975XL�BACKFLOW PREVENTER

OPTIONAL PRESSURE� GAUGE�

DIR

ECTI

ON

OF

FLO

W

OPTIONAL PRESSURE �GAUGE

SHUT-OFF

MODEL 975XL�RPZ BACKFLOW PREVENTER

PROTECTIVE�ENCLOSURE

MODEL DU�DIELECTRIC UNION

OPTIONAL PRESSURE� GAUGE

12" MIN.�30" MAX.

DIRECTION OF FLOW

MODEL DU�DIELECTRIC UNION

OPTIONAL PRESSURE� GAUGE

DIRECTION OF FLOW

OPTIONAL PRESSURE�GAUGE

MODEL 850�SHUT-OFF VALVE

DIR

ECTI

ON

OF

FLO

W

MODEL YB�STRAINER

MODEL DU�DIELECTRIC UNION

MODEL 850�SHUT OFF VALVE

DIRECTION OF FLOW

MODEL 90G

psi

60

100

80 20

40

PROTECTIVEENCLOSURE

MODEL 975XLBACKFLOW PREVENTER

DIRECTION OF FLOW

GAUGE

DIRECTION OF FLOW

GAUGE

SHUT-OFF

MODEL 70 MODLE 975XLBACKFLOW PREVENTER

PROTECTIVE ENCLOSURE

DIRECTION OF FLOW

SHUT-OFF�VALVE

DIRECTION OF FLOW

HOSE BIBB

WATER�METER

MODEL 70

DIRECTION OF FLOW

MODEL 500

MODEL 500FCMODEL 760

DIRECTION OF FLOW

MODEL 80CI

WILKINS MODEL P220 OR P3000PRESSURE RELIEF VALVE

OUTLET

SUPPLYSHUT-OFF

RETURN

HOT WATERBOILER

DRAINDRAIN

DIRECTION OF FLOW

WATERMETER

MODEL 850BALL VALVE

MODELNR3

HOSE BIBB

MODEL BFP-9HOSE BIBB

VACUUM BREAKER

SHUT-OFFVALVE

DIRECTION OF FLOW

HOSE BIBB

WATERMETER

MODEL 70

MODEL BFP-9HOSE BIBB

VACUUM BREAKER

MODEL 975XLRPZ BACKFLOW PREVENTER

OPTIONALPRESSUREGAUGE

MODEL DUDIELECTRIC UNION

WILKINS

MODEL 760

DIRECTION OF FLOW

MODEL 80CI

WILKINS MODEL P220 OR P3000PRESSURE RELIEF VALVE

OUTLET

SUPPLYSHUT-OFF

RETURN

HOT WATERBOILER

DRAINDRAIN

TROUBLESHOOTING Wilkins Pressure Regulators

Pipe lines in a water supply system must be of sufficient car-rying capacity to maintain adequate pressure at the most remote or highest fixture. Under the maximum probable fixture use, minimum adequate pressure is generally 8 to 15 lbs. but may be more, depending on the equipment being supplied. Relatively high service pressures which can create high water velocities in pipe lines would allow use of smaller pipes to satisfy fixture use. However, high velocity tends to cause whistling and humming. Reduction of pressure by the use of a pressure reducing valve,

in an attempt to eliminate such a condition, may reduce pipe line capacities below that which is adequate for maximum probable use. When high service pressures are in effect, either continuously or periodically, the application of a pressure reducing valve will be successful only when the installed pipe line is of adequate size to satisfy the system demand at the lower pressure. When actual water demands are unknown, the valve size should be no less then the existing pipe size.

PROBLEM POSSIBLE CAUSE OR CAUSES1. Pressure creeps or builds up in system above the setting of pressure reducing valve.

A. Thermal expansion of water as it is being heated.B. Foreign matter on seating face of seal ring.C. Cut, worn or chipped seal ring.D. Cut or worn stem o-ring or worn o-ring groove.

SOLUTION a. This is a natural consequence. It may happen each time that the heater runs. A pressure relief valve or expansion tank must be installed. This will not prevent pressure rise but should limit it to a safe level. b. Flush the reducing valve by opening one or two fixture outlets wide. If this does not correct the problem, remove seal ring for cleaning. c. Replace with new seal ring. Temporary repairs may be made by turning the seal ring over. d. Replace with new stem o-ring and/or cartridge.

2. Pressure and fixture flow is unsteady. A. Low water supply pressure in mains caused possibly by high area demand during certain periods of the day.B. Heavy periodic demands by appliances in the house.

SOLUTION a. This is a water department problem. It is due to the mains being inadequate for the demands made on them. b. House service lines may at times be inadequate for the load. Size of some pipelines may need to be increased. Pressure setting of reducing valve may be too low. c. Try increasing pressure before changing pipelines.

3. Small, inadequate flow from fixtures. A. Pipelines to fixtures may be too small or house main supply may be inadequate for normal fixture demand.B. Heavy periodic demands by appliances in the house.C. Screen clogged with debris.

SOLUTION a. It may be necessary to increase pipe sizes only in some sections of the system leading to the offending appliances or fixtures. Increasing the house service mains might be necessary if small supply is general at all fixtures. b. Raise pressure gradually by readjusting valve until this point is determined. c. Clean screen.

4. Valve appears to be noisy; hums, whistles or chatters.

A. Hum or whistle is usually caused by a high velocity of flow in pipelines causing vibration.B. Chatter usually originates with worn seat washer or loosely installed seal ring.

SOLUTION a. Pipelines could be small or too light. Reducing valves could be too small. Pipes and valves being small would accentuate this condition. b. Inspect seal ring. If a deep channel appears on seal ring face, replace or use the opposite side. c. Frequently noise appears in a faucet or appliance and seems to originate from the reducing valve. There is a general tendency to use streamline piping of a relatively small size. Velocity is naturally high and noise of fast moving water is not unusual.

WILKINS

1747 Commerce WayPaso Robles, CA 93446Customer Service Representatives available 5:30 am to 5:00 pm PSTMonday through Friday. Phone: 855-ONE-ZURN (855-663-9876)info@zurnwilkins.com

3544 Nashua Drive Mississauga, Ontario Canada L4V 1L2Phone: 905-405-8272Fax: 905-405-1292

www.zurn.com

P e r f o r m a n c e U n d e r P r e s s u r e

ZMKTG480-45, Rev. 4/13