LEVER ACTING DESIGNGAS APPLIANCE PRESSURE REGULATOR

Upright

When vented to the outdoorsthe 325 Series is suitable formulti-poise mounting. Whenusing the vent limitingdevice, the regulator (325-3,325-5A) must be mounted ina horizontal upright position.Install the regulator properlywith gas flowing as indicatedby the arrow on the casting(also see the Safety WarningInstructions bulletin).

325-3*, 325-5A*, 325-7Pipe sizes from 3/8” to 1-1/2”

CSA 6.3 and ANSI Z21.18Design Certified - 325-3, 325-5A

Maximum Inlet Pressure:

ANSI Z21.18 Certified - 325-3, 325-5A .....2psi (140 mbar),

Maxitrol-tested: all models......................10 psi ( 690 mbar)

With 12A09 or 12A39:Max. inlet pressure (LP)........................2 psi (140 mbar)Max. inlet pressure (natural)...................5 psi (345 mbar)

Emergency Exposure LimitsAll models (inlet side only).......................65 psi (4.5 bar)

Maximum Individual LoadLargest single appliance served by the regulator325-3......................................................100,000 Btu/hr325-5A....................................................250,000 Btu/hr325-7......................................................900,000 Btu/hr

Capacity:Total load of all appliances combined325-3 (3/8”, 1/2”)......................................150,000 Btu/hr325-5A (1/2”, 3/4”, 1”)..................................300,000 Btu/hr325-7 (1-1/4”, 1-1/2”)..............................1,000,000 Btu/hr

Ambient Temperature LimitsAll models...............................-40° to 205°F (-40° to 96°C)DVGW...........................................32° to 140°F (0° to 60°C)EN................................................5° to 176°F (-15° to 80°C)

Vent Pipe Connection Size:325-3 ..............................................................1/8" NPT325-5A.............................................................3/8" NPT325-7................................................................1/2" NPT

Gases: Suitable for application in natural, manufactured, mixedgases, liquefied petroleum gases, and LP gas-air mixture pipingsystems.

NOTE: All Maxitrol gas appliance regulators must be installedand operated in accordance with Maxitrol's 'Safety Warning'bulletin.

* Design Certified - 325-3, 325-5A

5 psi (345 mbar)

© 2008, Maxitrol Company, All Rights Reserved 1

2

Lever Acting Design

325 series

NOTE: Vent limiters are designed for use indoors and inspaces where limiting the amount of gas escapement due todiaphragm failure is critical. Vent limiters are not to beused outdoors if they are exposed to the environment.13A15 vent protector is available for outdoor use when ventprotection is required.

The 325 Series regulators are Maxitrol-tested for inletpressures up to 10 psi (CSA certified for 2 psi and 5 psi).With the 12A09 or 12A39 installed, maximum inlet pressureis 2 psi (LP) and 5 psi (natural). Inlet pressures exceeding 2psi (LP), or 5 psi (natural) require a vent line.

The self-aligning valve is made of nitrile rubber. Housingsare durable aluminum die castings and all internal parts arecarefully selected and corrosion resistant. The diaphragmsare of high quality supported synthetic rubber compounds.

The 325 Series regulators are suitable for multi-poisemounting. But when using the vent limiting device, theregulator (325-3, 325-5A) must be mounted in ahorizontal upright position. Install the regulator properlywith gas flowing as indicated by the arrow on the casting.

These regulators provide no downstream over-pressureprotection in the event of failure. At supply pressures inexcess of 2 psi they should not be used unless downstreamappliance controls are rated for supply pressure or protectedby some other means. Consult Maxitrol Company foradditional assistance.

FEATURES:• Designed for multi-poise mounting...• Self-aligning valve with lever action for dead end lockup...• Durable, corrosion-resistant construction...• High performance type for pounds to inches reduction...• Available in six pipe sizes from 3/8" to 1-1/2"...

BENEFITS:• Ease of installation...• Longer life, less maintenance...• May be used for both 2 psi and 5 psi corrugated

stainless steel tubing (CSST) systems.• Precise regulation from pilot flows to full

regulator capacity...• Meets many utility specifications.

325-3*, 325-5A* & 325-7

The 325 Series is a pounds to inches regulator, meeting utilityspecifications. The 325 Series regulator is for use onresidential, commercial, and industrial applications whereadequate inlet pressures are available.

They are a high performance type regulator and can be usedas a single stage regulator - reducing pounds pressure tonormal burner pressure. They can also be used as a lineregulator on equipment already fitted with an applianceregulator.

The 325-3 and 325-5A models are CSA certified and widelyaccepted with 2 psig and 5 psig house piping systems. Infact, the entire concept (using semi-rigid copper or flexiblestainless steel tubing) would not have been possible withoutthe development of the compact 325 series regulators.

The 325-7, designed especially for the growing segment ofelectronic ignition equipment, permits the utilization of greatercapacities without sacrificing performance. All 325 Seriesmodels are also certified through DVGW to European EN 88.

To deliver positive dead-end lock up, the 325 Series feature ahigh leverage valve linkage assembly. Lockup pressure canvary with the speed of the solenoid valve and its location. Theregulators are capable of precise regulating control from fullflow down to pilot flows.

As an optional accessory, the 325-3 and 325-5A offerautomatic vent limiting devices. The 12A09 and 12A39 ventlimiters eliminate the need to run vent piping to a safe area -in the event of a diaphragm rupture, gas escapement islimited to within the ANSI/CSA standards level.

* CSA design certified© 2008, Maxitrol Company, All Rights Reserved

3

Capacities and Pressure Drop

Pressure Drop ChartSizing Instructions

Pre

ssur

e D

rop

(P)

When 325 Series regulators are used on 2 psig piping systems -often times the 2 psig residential systems are sized with a 1-1/2psi pressure drop through the copper or stainless steel tubing.This means there will be 2 psi at the inlet of the regulator underno flow conditions, and 1/2 psi at the regulator inlet undermaximum flow conditions.

To select a 325 series appliance regulator of ample flow - onemust know:

1. Available inlet pressure (maximum static/minimum operating).2. Desired outlet pressure.3. Required maximum flow rate.4. Pipe size.

Example: To select a 325 series regulator of ample capacity tohandle flow. . .KNOWN:Desired flow rate 145 CFH; pipe size 1/2"; operating inletpressure 2 psi; outlet pressure 7" w.c.; lockup required.SOLUTION:Check pressure drop chart above - the 325-3's pressure drop ata flow rate of 145 CFH is 7" w.c. - well below the availabledifferential of 1.75 psi. The 325-3 (1/2") used with a 4" to 12"spring, set at 7", is the correct regulator to use for this application.

*NOTE: Maximum Individual Load: 325-3 is 100 CFH (2.8 m3/h), 325-5A is 250 CFH (7.0 m3/h), 325-7 is 900 CFH (25.5 m3/h)Approval based on use as an appliance regulator.

CAPACITIES - based on 1" w.c. pressure drop, from set point*. 0.64 sp gr gas expressed in CFH (m3/h).

PRESSURE DROP - 0.64 sp gr gas expressed in CFH (m3/h) (for system pressure drop calculations)

Model NumberOutlet

PressureSet Point

CSAMax.CFH

1/2 psi(34 mbar)

3/4 psi(52 mbar)

1 psi(69 mbar)

2 psi(138 mbar)

5 psi(345 mbar)

10 psi(690 mbar)

325-3*

325-5A*

325-7

4.0” w.c. 150 160 (4.5) 190 (5.4) 220 (6.2) 220 (6.2) 300 (8.5) 320 (9.1)

7.0” w.c. 150 120 (3.4) 150 (4.2) 180 (5.1) 220 (6.2) 290 (8.2) 320 (9.1)

10.0” w.c. 150 100 (2.8) 120 (3.4) 150 (4.2) 220 (6.2) 280 (7.9) 320 (9.1)

4.0” w.c. 300 300 (8.5) 340 (9.6) 416 (11.8) 500 (14.2) 600 (17.0) 680 (19.3)

7.0” w.c. 300 245 (6.9) 315 (8.9) 340 (9.6) 480 (13.6) 600 (17.0) 680 (19.3)

10.0” w.c. 300 225 (6.4) 270 (7.6) 312 (8.8) 430 (12.2) 560 (15.9) 680 (19.3)

4.0” w.c. - 670 (19.0) 900 (25.5) 1050 (29.7) 1450 (41.1) 1750 (49.6) 2000 (56.6)

7.0” w.c. - 590 (16.7) 760 (21.5) 900 (25.5) 1250 (35.4) 1750 (49.6) 2000 (56.6)

10.0” w.c. - 470 (13.3) 650 (18.4) 800 (22.7) 1250 (35.4) 1750 (49.6) 2000 (56.6)

Operating Inlet Pressure

© 2008, Maxitrol Company, All Rights Reserved

Model 7.0” w.c. (17 mbar) 1/2 psi (34 mbar) 3/4 psi (52 mbar) 1 psi (69 mbar) 2 psi (138 mbar)325-3

325-5A325-7

145 (4.0) 204 (5.8) 250 (7.0) 289 (8.2) -

338 (9.6) 476 (13.5) 583 (16.5) 673 (19.1) -

690 (19.5) 972 (27.6) 1191 (33.8) 1375 (39.0) 1975 (55.9)

6 - 10(15 - 25)

B

C

A

B

C

A

B

C

A

Dimensions and Spring Ranges

325-7

325-3 325-5A

DIMENSIONS - inches (millimeters)

* standard models NPT, 'M' models available with BSP threads

ModelNumber

PipeSize*

SwingRadius

Call-OutsA B C

325-3

325-5A

325-7

3/8 x 3/81/2 x 1/2

1/2 x 1/23/4 x 3/4

1 x 1

1-1/4 x 1-1/41-1/2 x 1-1/2

3(76)

4-7/8(124)

6-1/8(156)

3-1/2(89)

5-1/4(133)

7-1/4(184)

4-1/4(108)

5-7/8(149)

8(203)

3-7/8(98)

5-7/16(138)

7(178)

SPRING SELECTION CHART - inches w.c. (mbar) unless noted

ModelNumber Other Springs Available

325-3

325-5A

325-7

2 - 6(5 - 15)

10 - 22(25 - 55)

15 - 30(37 - 75)

1 - 2 psi(69 - 139)

2 - 6(5 - 15)

10 - 22(25 - 55)

15 - 30(37 - 75)

1 - 2 psi(69 - 139)

2 - 5(5 - 12)

10 - 22(25 - 55)

15 - 30(37 - 75)

20 - 42(50 - 104)

CSA Certified

5 - 9(12.5 -22.5)

7 - 11(17 - 27)

7 - 11(17 - 27)

5 - 9(12.5 - 22.5)

7 - 11(17 - 27)

6 - 10(15 - 25)

7 - 11(17 - 27)

- - - -

2 psi (138 mbar) 5 psi (345 mbar)Standard

Spring

4 to 12(10 to 30)

4 to 12(10 to 30)4 to 12

(10 to 30)

www.maxitrol.com© 2008, Maxitrol Company,

All Rights Reserved.

Maxitrol Company23555 Telegraph Rd., PO Box 2230Southfield, MI 48037-2230 U.S.A.

325LVR_MS_EN_03.2008Replaced Bulletin MS2055-03/05

4

The 325 Series is suitable for multi-poisemounting. But when using the vent limiting

device, the regulator (325-3L, 325-5AL) mustbe mounted in a horizontal upright position.Install the regulator properly with gas flowingas indicated by the arrow on the casting (alsosee the Safety Warning Instructions bulletin).

NOTE: Ventlimiters are designed for use indoors and inspaces where limiting the amount of gas escapement due todiaphragm failure is critical. Vent limiters should not beused outdoors if they are exposed to theenvironment. 13A15 vent protector is available foroutdoor use when vent protection is required.

Upright

Line Pressure RegulatorsLever Acting Design

325-3L, 325-5AL, 325-7LPipe sizes from 3/8" to 1½"

CSA Design CertifiedZ21.80 / CAN 6.22

Maximum Inlet Pressure:CSA Certified .............................. 2 psi (140 mbar)

Minimum Inlet Pressure:CSA Certified ............................. 1 psi (70 mbar)

Emergency Exposure Limits:(inlet side only) ........................................ 65 psi (4.5 bar)

Outlet Pressure Range:Certified spring .................................... 7 - 11 inches w.c.

Maximum Individual Load:Largest single appliance served by the regulator325-3L ..................................................... 140,000 Btu/hr325-5AL ................................................... 300,000 Btu/hr325-7L ...................................................... 900,000 Btu/hr

Capacity:Total load of all appliances combined325-3L (3/8", 1/2") .................................... 250,000 Btu/hr325-5AL (1/2") .......................................... 425,000 Btu/hr325-5AL (3/4", 1") ..................................... 550,000 Btu/hr325-7L (1¼", 1½") ................................. 1,000,000 Btu/hr

Venting:325-3L (optional 12A09 vent limiter) .................1/8" NPT325-5AL (optional 12A39 vent limiter) .............. 3/8" NPT325-7L ............................................................. 1/2" NPT

Gases:Suitable for natural and liquefied petroleum gases.

Ambient Temperature Limits:-40° to 205°F (-40° to 96°C)

Note: All Maxitrol gas appliance regulators must be installedand operated in accordance with Maxitrol's 'Safety Warning'bulletin.

For 2-psi piping systemsFor applications from 2-psi to 5-psi, please see bulletin

LPROPD_MS_EN.

© 2008, Maxitrol Company, All Rights Reserved. 1

2

Lever Acting Design

325 Series

Install the regulator properly with gas flowing as indicatedby the arrow on the casting.To deliver positive dead-end lock up, the 325 Seriesfeature a high leverage valve linkage assembly. Lockuppressure can vary with the speed of the solenoid valveand its location. The regulators are capable of preciseregulating control from full flow down to pilot flows.The self-aligning valve is made of nitrile rubber.Housings are durable aluminum die castings and allinternal parts are carefully selected and corrosionresistant. The diaphragms are of high quality supportedsynthetic rubber compounds.The regulator is certified for inlet pressures up to 2 psi.Over-pressure protection is not required for supplypressures up to 2-psi. These regulators provide nodownstream over-pressure protection in the event offailure. At supply pressures in excess of 2 psi, the newANSI Z21.80 line regulator standard requires meansapproved and tested with the regulator to limit thedownstream pressure to 2-psi maximum, in the event ofregulator failure. Consult Maxitrol Company forassistance.Other 325 Series regulators will continue to be availableas CSA certified appliance regulators, as well as non-certified models for up to 10-psi inlet pressure (seebulletin 325LVR_MS_EN).

L-Model Line Pressure Regulators

Although Maxitrol's 325 Series are certified (ANSI Z21.18)as appliance regulators (see bulletin 325LVR_MS_EN), inthe past they have often been used as line pressureregulators. Until very recently, there was no standard forline pressure regulators.Z21.80 is the new ANSI standard for line pressureregulators, intended for application in natural gas pipingsystems. Maxitrol's new 325 Series L-models are CSAcertified (Z21.80) for 2-psi inlet pressure, with the 7 to 11(inches w.c. outlet) spring.The L-models are Class 1, pounds to inches regulators,meeting utility specifications, for use on2-psi piping systems such as CSST (corrugated stainlesssteel) or semi-rigid copper tubing. The regulators are ahigh performance type - reducing pounds pressure to alevel within the appliance's operating supply range. Theline regulator is located upstream of equipment alreadyfitted with an appliance regulator.The entire 2-psi system concept would not have beenpossible without the development of the compact 325Series regulator.As optional accessories, the 325-3L and 325-5AL offeran automatic vent limiting device. The 12A09 or 12A39vent limiter eliminates the need to run vent piping to anoutside area - in the event of a diaphragm rupture, gasescapement is limited to within the ANSI standards level.The 325 Series are suitable for multi-poise mounting.But when using a vent limiting device, the regulatormust be mounted in a horizontal upright position.

The new line pressure regulator standard - ANSI Z21.80

FEATURES:• Designed for multi-poise mounting...• Self-aligning valve with lever action for dead end lockup...• Durable, corrosion-resistant construction...• High performance type for pounds to inches reduction...• Available in 3/8" to 1½" pipe sizes...

BENEFITS:• Ease of installation...• Longer life, less maintenance...• For use on 2-psi piping systems such as CSST

(corrugated stainless steel) or semi-rigid copper tubing...• Precise regulation from pilot flows to full regulator

capacity...• Meets many utility specifications.

© 2008, Maxitrol Company, All Rights Reserved.

Capacities and Pressure DropCAPACITIES - 0.64 sp gr gas expressed in CFH (m3/h).

Pressure Drop Chart

Pre

ssur

e D

rop

(P)

Flow Rate.3 1 3 10 30m3/hr

CFH.81

10

100

Inch

es w

.c.

mba

r

PRESSURE DROP - 0.64 sp gr gas expressed in CFH (m3/h)

Capacity:Total load of all appliances combined325-3L (3/8", 1/2") .................................250,000 Btu/hr325-5AL (1/2") .......................................425,000 Btu/hr325-5AL (3/4", 1") ..................................550,000 Btu/hr325-7L (1¼", 1½") .............................1,000,000 Btu/hr

Maximum Individual Load:Largest single appliance served by the regulator325-3L .................................................140,000 Btu/hr325-5AL ............................................... 300,000 Btu/hr325-7L ..................................................900,000 Btu/hr

3

Model Number(pipe size)

Outlet PressureSet Point

Operating Inlet Pressure

1 psi (69 mbar) 1 1/2 psi (103 mbar) 2 psi (138 mbar)

325-3L

(3/8", 1/2")

325-5AL

(1/2")

325-5AL

(3/4", 1")

325-7L

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

7.0" w.c.

10.0" w.c.

7.0" w.c.

10.0" w.c.

7.0" w.c.

10.0" w.c.

7.0" w.c.

10.0" w.c.

250 (7.1)

230 (6.5)

425 (12.0)

425 (12.0)

550 (15.6)

535 (15.1)

1000 (28.3)

1000 (28.3)

250 (7.1)

250 (7.1)

425 (12.0)

425 (12.0)

550 (15.6)

550 (15.6)

1000 (28.3)

1000 (28.3)

250 (7.1)

250 (7.1)

425 (12.0)

425 (12.0)

550 (15.6)

550 (15.6)

1000 (28.3)

1000 (28.3)

© 2008, Maxitrol Company, All Rights Reserved.

Model Number 7.0" w.c. (17mbar) 1/2 psi (34 mbar) 3/4 psi (52 mbar) 1 psi (69 mbar)

325-3L 145(4.0)

204(5.8)

250(7.0)

289(8.2)

325-5AL 338(9.6)

476(13.5)

583(16.5)

673(19.1)

325-7L 690(19.5)

972(27.6)

1191(33.8)

1375(39.0)

Dimensions and Spring Range

325-7L

Sizing Instructions

325-3L

Frequently 2-psi piping systems are sized with a 1 psi pressure drop through the copper or stainless steel tubing. This means therewill be 2 psi at the inlet of the regulator under no flow conditions, and 1 psi at the regulator inlet under maximum flow conditions.

SOLUTION:A. In the Capacities chart (page 3), locate rows where 1/2" (pipe

size) models with 7" w.c. outlet pressure - intersect with - 1 psioperating inlet pressure column.(325-3L = 250 CFH, 325-5AL = 425 CFH).

B. The total Btu load requirement cannot exceed the equivalentCFH result from step-A. The combined 145,000 Btu/hrrequirement does not exceed either model's capacity.

C. The 90,000 Btu/hr single largest appliance rating is below the325-3L maximum individual load capacity of 140,000 Btu/hr.

D. The 325-3L is the smallest acceptable line regulator for thisapplication.

To select a line regulator of ample flow - one must know:1. Available inlet pressure (maximum static/minimum operating).2. Desired outlet pressure.3. Required maximum capacity (total load, all appliances

combined),and maximum individual load.4. Pipe size.Example: To select a line regulator of ample capacity to handleflow. . .KNOWN:A. Required: 1/2" NPT line regulator, outlet pressure of 7" w.c.,

with a static pressure of 2-psi, and a minimum operating inletpressure of 1 psi.

B. Combined Btu rating of all appliances to be served by theregulator: 145,000 Btu/hr.

C. Largest single appliance's Btu rating: 90,000 Btu/hr.

Outlet Pressure Range (all models):Certified spring .................................... 7 - 11 inches w.c.

DIMENSIONS - inches (millimeters)

* standard models NPT threads.'M' models available with ISO7 PL, 'MK' models ISO7 TR.

325-5AL

Maxitrol Company23555 Telegraph Rd., P.O. Box 2230Southfield, MI 48037-2230 U.S.A.

325LPR_MS_EN_04.2008Replaced Bulletin MS2066

Call-OutsModel

NumberPipeSize*

SwingRadius A B C

325-3L 3/8 x 3/81/2 x 1/2

3(76)

3 1/2(89)

4 1/4(108)

3 7/8(98)

325-5AL1/2 x 1/23/4 x 3/4

1 x 1

4 7/8(124)

5 1/4(133)

5 7/8(149)

5 7/6(138)

325-7L 1 1/4 x 1 1/41 1/2 x 1 1/2

6 1/8(156)

7 1/4(184)

8(203)

7(178)

www.maxitrol.com© 2008, Maxitrol Company,

All Rights Reserved

4

1

Line Pressure Regulators and Over-Pressure Protection Devices For piping systems up to 5 psi

© 2008 Maxitrol Company, All Rights Reserved

SYSTEM COMPONENTS

Maximum Inlet Pressure:CSA Certified ............................................. 5 psi (345 mbar)

Emergency Exposure Limits:(inlet side only) ............................................. 65 psi (4.5 bar)

Outlet Pressure Range:Certified spring .......................................... 7 - 11 inches w.c.

Maximum Individual Load:Largest single appliance served (regulator with OPD)

325-3L47 (3/8”, 1/2”) (w/OPD 47 attached) ... 125,000 Btu/hr325-3L48 (1/2”) (w/OPD 48 attached) ............ 200,000 Btu/hr325-5AL48 (1/2”) (w/OPD 48 attached) ......... 235,000 Btu/hr325-5AL48 (3/4”) (w/OPD 48 attached) ......... 320,000 Btu/hr325-5AL600 (3/4”) (w/OPD 600 attached) ...... 425,000 Btu/hr325-5AL600 (1”) (w/OPD 600 attached) ......... 465,000 Btu/hr

Capacity:Total load of all appliances combined (regulator with OPD)

325-3L47 (3/8”, 1/2”) (w/OPD 47 attached) ....125,000 Btu/hr325-3L48 (1/2”) (w/OPD 48 attached) ........... 200,000 Btu/hr325-5AL48 (1/2”) (w/OPD 48 attached) ......... 235,000 Btu/hr325-5AL48 (3/4”) (w/OPD 48 attached) ......... 320,000 Btu/hr325-5AL600 (3/4”) (w/OPD 600 attached) ...... 425,000 Btu/hr325-5AL600 (1”) (w/OPD 600 attached) ......... 465,000 Btu/hr

Venting:OPD 47 ................... integral vent limiting orifice w/dust capOPD 48 (optional 12A09 vent limiter) .................... 1/8” NPTOPD 600 (optional 12A09 vent limiter) .................... 1/8” NPT

Gases: Intended for application in natural gas piping systems up to 5 psi.

Ambient Temperature Limits: -40° to 205°F (0° to 96°C)

Note: All Maxitrol gas appliance regulators must be installed and operated in accordance with Maxitrol’s ‘Safety Warning’ bulletin.

CSA Design Certified Z21.80 / CAN 6.22

Attention: Line pressure regulators with separate overpressure protection devices shall be factory preassembled, and supplied to the field as a unit.

The 325 Series is suitable for limited horizontal mounting (less than or equal to 90° from upright). But when using the vent limiting device, the regulator must be mounted in a horizontal upright position. Install the regulator properly with gas flowing as indicated

by the arrow on the casting (also see the Safety Warning Instructions bulletin).

NOTE: Vent limiters are designed for use indoors and in spaces where limiting the amount of gas escapement due to diaphragm failure is critical. Vent limiters should not be used outdoors if they are exposed to the environment. 13A15 vent protector is available for outdoor use when vent protection is required.

Upright

To deliver positive dead-end lock up, the 325 Series feature a high leverage valve linkage assembly. Lockup pressure can vary with the speed of the solenoid valve and its location. The regulators are capable of precise regulating control from full flow down to pilot flows.

The self-aligning valve is made of nitrile rubber. Housings are durable aluminum die castings and all internal parts are carefully selected and corrosion resistant. The diaphragms are of high quality supported synthetic rubber compounds.

The regulator with OPD is certified for inlet pressures up to 5-psi, and can withstand emergency exposure inlet pressure up to 65-psi. The regulator alone provides no downstream over-pressure protection in the event of failure.

Other 325 Series regulators will continue to be available as CSA certified appliance regulators, as well as non-certified models for up to 10-psi inlet pressure (see bulletin 325LVR_MS_EN).

NOTE: Immediately after installation and prior to operating any appliance: It is important to check the preassembled pipe connection between the regulator and OPD for leakage. Even though the Maxitrol 5 psi line regulator with OPD is shipped as an assembly, installation of the assembly can result in turning (tightening or loosening) of the preassembled connection. If gas leakage is detected, follow the same procedures to stop the leak as you would use with any field pipe connection, and repeat step number 5 according to the ‘Safety Warning’ bulletin.

2© 2008 Maxitrol Company, All Rights Reserved

FEATURES • CSA certified for up to 5-psi inlet pressure • Over-pressure protection device (OPD) to limit downstream pressure in case of regulator failure • Maxitrol OPD approved and tested with the regulator • Self-aligning valve with lever action for dead end regulator lockup • Optional vent limiter eliminates the need to run vent piping to an outside area

BENEFITS • Meets ANSI standard Z21.80 for line pressure regulators — for use on piping systems such as CSST or semi-rigid copper tubing up to 5-psi • OPD provides required downstream over- pressure protection for supply pressures in excess of 2-psi • Pounds to inches regulator provides precise control from pilot flows to full regulator capacity • Meets many utility specifications

THE NEW LINE PRESSURE REGULATOR STANDARD - ANSI Z21.80

Although Maxitrol’s 325 Series are certified (ANSI Z21.18) as appliance regulators (see bulletin 325LVR_MS_EN), in the past they have often been used as line pressure regulators. Until very recently, there was no standard for line pressure regulators.

Z21.80 is the new ANSI standard for line pressure regulators, intended for application in natural gas piping systems. As of May 1, 2002, CSA requires that all line pressure regulators above 2-psi must leave the factory pre-assembled and leak tested. At supply pressures in excess of 2-psi, the new line regulator standard requires a means (an over-pressure protection device / OPD) — approved and tested with the regulator — to limit the downstream pressure to 2-psi maximum, in the event of regulator failure. Line pressure regulators with separate overpressure protection devices shall be factory preassembled, and supplied to the field as a unit. Maxitrol-built OPDs provide the required downstream over-pressure protection.

As optional accessories, the regulators and OPDs offer an automatic vent limiting device. The 12A09 or 12A39 vent limiters eliminate the need to run vent piping to an outside area - in the event of a diaphragm rupture, gas escapement is limited to within the ANSI standards level. The 325 Series are suitable for limited horizontal mounting (less than or equal to 90° from upright) - but when using a vent limiting device, the regulator must be mounted in a horizontal upright position for best performance. Install the regulator properly with gas flowing as indicated by the arrow on the casting.

3© 2008 Maxitrol Company, All Rights Reserved

CAPACITIES AND PRESSURE DROP-Applications above 2 psi, Regulator and OPD

Capacity:Total load of all appliances combined (regulator & OPD)

325-3L47 (3/8”, 1/2”) (w/OPD 47) .............. 125,000 Btu/hr325-3L48 (1/2”) (w/OPD 48) ....................... 200,000 Btu/hr325-5AL48 (1/2”) (w/OPD 48) ..................... 235,000 Btu/hr325-5AL48 (3/4”) (w/OPD 48) ................... 320,000 Btu/hr325-5AL600 (3/4”) (w/OPD 600) ............... 425,000 Btu/hr325-5AL600 (1”) (w/OPD 600) .................. 465,000 Btu/hr

Maximum Individual Load:Largest single appliance served (regulator & OPD)

325-3L47 (3/8”, 1/2”) (w/OPD 47) ................ 125,000 Btu/hr325-3L48 (1/2”) (w/OPD 48) .......................... 200,000 Btu/hr325-5AL48 (1/2”) (w/OPD 48) ....................... 235,000 Btu/hr325-5AL48 (3/4”) (w/OPD 48) ...................... 320,000 Btu/hr325-5AL600 (3/4”) (w/OPD 600) .................. 425,000 Btu/hr325-5AL600 (1”) (w/OPD 600) ..................... 465,000 Btu/hr

PRESSURE DROP CHART

4Maxitrol Company23555 Telegraph Rd., PO Box 2230Southfield, MI 48037-2230

LPROPD_MS_EN_07.2008 - Replaced Bulletin MS2076

www.maxitrol.com© 2008 Maxitrol Company

All Rights Reserved

SOLUTION:A. In the Capacities table (page 3), locate [325-3L47 (1/2”)

= 125 CFH, 325-3L48 (1/2”) = 200 CFH, 325-5AL48 (1/2”) = 235 CFH].

B. The total Btu load requirement cannot exceed the equivalent CFH result from step-A. The combined 145,000 Btu/hr requirement exceeds the 325-3L47 (1/2”) capacity, but is less than that of the 325-3L48 (1/2”) and 325-5AL48 (1/2”).

C. The 90,000 Btu/hr single largest appliance rating is below the 325-3L48 maximum individual load capacity of 200,000 Btu/hr.

D. The 325-3L48 is the smallest acceptable (1/2”) line regulator with OPD for this application.

DIMENSIONS AND SPRING RANGE-Applications above 2 psi, Regulator and OPD

Dimensions - inches (millimeters)

Model Number

Pipe Size*

Swing Radius

Call OutsA B C

325-3L47 3/8 x 3/81/2 x 1/2

3(76)

3.5(90)

8(203)

3.9(100)

325-3L48 1/2 x 1/2 3(76)

3.5(90)

8.5(216)

3.9(100)

325-5AL48 1/2 x 1/23/4 x 3/4

4.4(112)

5.3(135)

10(254)

5.4(140)

325-5AL600 3/4 x 3/41 x 1

4.4(112)

5.5(140)

11(279)

5.4(140)

* standard models NPT threads.

NOTE: Dimensions are to be used only as an aid in designing clearance for the regulator. Actual production dimensions may vary somewhat from those shown.

Outlet Pressure Range (all models):Certified spring .................................... 7 - 11 inches w.c.

SIZING INSTRUCTIONS

To select a line regulator of ample flow - one must know:1. Available inlet pressure (maximum static/minimum op-

erating).2. Desired outlet pressure.3. Required maximum capacity (total load, all appliances

combined), and maximum individual load.4. Pipe size.

Example: To select a line regulator with OPD of ample ca-pacity to handle flow. . .

KNOWN:A. Required: 1/2” NPT line regulator with OPD, outlet pres-

sure of 7” w.c., with a static pressure of 5-psi, and a mini-mum operating inlet pressure of 3/4 psi.

B. Combined Btu rating of all appliances to be served by the regulator: 145,000 Btu/hr.

C. Largest single appliance’s Btu rating: 90,000 Btu/hr.

A

B

C

A

B

C

A

B

C

A

C

B

325-3L47

325-3L48

325-5AL48

325-5AL600

Attention: Line pressure regulators with separate overpressure protection devices shall be factory preassembled, and supplied to the field as a unit.