Maxitrol 325-3(B) User Manual

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325 Series Appliance Pressure Regulators

For 2 psi, 5 psi, and 10 psi piping systems.

TABLE OF CONTENTS

Description .................................................................................. 1

Specications ........................................................................... 1, 2

Pressure Drop ............................................................................ 2

Capacities ................................................................................... 3

Dimensions ................................................................................. 3

Spring Selection Chart .............................................................. 4

Sizing Instructions ...................................................................... 4

DESCRIPTION

325 Series pounds to inches regulators are for use on residential, commercial, and industrial applications.

325-3 325-7A

325-5A

The 325 Series features a high leverage valve linkage assembly to deliver positive dead-end lock-up. The regulators are capable of

precise regulating control from full ow down to pilot ow.

B Models: Imblue Technology™ increases corrosion resistance and provides extra protection against the elements for regulators used in outdoor applications.

NOTE: (B) in model number designates Imblue Technology™.

NOTICE

These regulators provide no downstream over-pressure protection in the event of failure. At supply pressures in excess of 2 psi,

they should not be used unless downstream appliance controls

are rated for supply pressure or protected by some other means. For Technical Support contact a Maxitrol Technical Support Representative. See Maxitrol Safety Warning Instructions, GPR_MI_EN.ES

SPECIFICATIONS

Gases

Suitable for natural, manufactured, mixed gases, liqueed

petroleum gases, and LP gas-air mixtures.

Approvals CSA: ANSI Z21.18/CSA 6.3

Maximum Inlet Pressure

Model CSA Certied Maxitrol Tested

325-3(B) 325-5A(B)

325-7A(B) Not Certied

Model

325-3(B) 325-5A(B) 325-7A(B)

Outlet Pressure Range (CSA Certied)

Model Inlet Pressure Spring Ranges

325-3(B) 2 psi (13.8 kPa)

325-3(B) 325-5A(B)

2 psi (13.8 kPa), 5 psi (34.5 kPa)

10 psi (69 kPa)

With 12A09, 12A39, or 12A49 Installed

Maximum Inlet Pressure

NAT: 5 psi (34.5 kPa) LP: 2 psi (13.8 kPa)

5-9” w.c. 7-11” w.c.

5 psi (34.5 kPa)

6-10” w.c. 7-11” w.c.

325-3B

Figure 1: 325 Series Appliance Regulators

325-5AB

325-7AB

Emergency Exposure Limits

All models (Inlet Side Only)................................... 65 psi (450 kPa)

Maximum Individual Load

Largest single appliance served by the regulator.

325-3(B) .................................................................100,000 Btu/hr

325-5A(B) .............................................................. 250,000 Btu/hr

325-7A(B) ........................................................... 1,250,000 Btu/hr

Capacity

Total load of multiple appliances combined.

325-3(B) (3/8”, 1/2”) ................................................150,000 Btu/hr

325-5A(B) (1/2”, 3/4”, 1”) ........................................ 300,000 Btu/hr

325-7A(B) (1 1/4”, 1 1/2”) .................................... 1,250,000 Btu/hr

NOTE: Capacity table is used to determine the maximum multiple

appliance load.The largest single appliance served by the regulator should not exceed the maximum individual load

specied above.

Ambient Temperature Limits

All Models .................................... -40ºF to 205ºF (-40ºC to 96ºC)

Vent Pipe Connections

325-3(B) ..........................................................................1/8” NPT

325-5A(B) ....................................................................... 3/8” NPT

325-7A(B) ........................................................................1/2” NPT

Mounting Position

The 325 Series is suitable for multi-poise

mounting, but when used with a vent

limiting device, the regulator must be mounted in a horizontal upright position (see Figure 2). Install the regulator

properly with gas owing as indicated by the arrow on the casting. (See Maxitrol

Safety Warning Instructions, GPR_MI_ EN.ES)

UPRIGHT

Figure 2: 325 Regulator in Upright Postion

325 Series Appliance Pressure Regulators

12A09 (1/8” NPT)

Figure 3: Vent Accessories

Vent Limiting Devices

Vent Protectors

13A15 (1/8” NPT)

12A39 (3/8” NPT)

13A15-5 (3/8” NPT)

12A49 (1/2” NPT)

13A25 (1/2” NPT)

Vent Limiting Device for Indoor Applications:

325-3(B) .............................................................................12A09

325-5A(B) ..........................................................................12A39

325-7A(B) ...........................................................................12A49

NOTICE

Maxitrol vent limiting devices eliminate the need to run vent piping to the outside. Vent limiting devices are designed for

use indoors and in spaces where limiting the amount of gas

escapement due to diaphragm failure is critical. Vent limiting

devices should not be used outdoors if they are exposed to

the environment. Vent protectors are available for all outdoor applications to ensure proper vent protection.

Vent Protectors for Outdoor Applications:

325-3(B) .............................................................................13A15

325-5A (B) ........................................................................13A15-5

325-7A (B) ............................................................................13A25

PRESSURE DROP - 0.64 sp. gr. gas expressed in CFH (m

/h) (for system pressure drop calculations)

Pressure Drop

Model

325-3(B) 145 (4.0) 204 (5.8) 250 (7.0) 289 (8.2)

325-5A(B) 338 (9.6) 476 (13.5) 583 (16.5) 673 (19.1)

7.0” w.c.

(1.7 kPa)

1/2 psi

(3.4 kPa)

3/4 psi

(5 kPa)

1 psi

(7 kPa)

2 psi

(13.8 kPa)

325-7A(B) 815 (23.1) 1149 (32.5) 1405 (39.8) 1624 (46.0) 2305 (65.3)

NOTE: All Maxitrol gas appliance regulators must be installed and operated in accordance with Maxitrol’s Safety Warning Instructions.

Flow Rate (m3 @ 0.64 SG gas)

100

Pressure Drop (in. w.c.)

1 2 3 4 5 6 8 10 20 30 40 60 80 100 200

)

(

)

(

)

(

9 8

Pressure Drop (kPa)

1 .9 .8

10 100 1000 10000

Figure 4: Pressure Drop Chart

Flow Rate (cfh @ 0.64 SG gas)

325 Series Appliance Pressure Regulators

CAPACITIES - Based on 1” w.c. pressure droop from set point**. 0.64 sp gr gas expressed in CFH (m

Model Number

(pipe size)

325-3(B) (3/8”, 1/2”)

325-5A(B) (1/2”, 3/4”, 1”)

325-7A(B) (1 1/4”, 1 1/2”)

Maximum approved capacity for 325-3(B) is 100 CFH (2.8 m3/h), 325-5A(B) is 250 CFH (7.1 m3/h), 325-7A(B) is not CSA certied. Approval based on use as an appliance regulator. ** Set points (in CFH): 325-3(B) = 50, 325-5A(B) = 150, 325-7A(B) = 500.

Outlet Pressure Set Point

4.0” w.c.

(1.0 kPa)

7.0” w.c.

(1.7 kPa)

10.0” w.c.

(2.5 kPa)

4.0” w.c.

(1.0 kPa)

7.0” w.c.

(1.7 kPa)

10.0” w.c.

(2.5 kPa)

4.0” w.c.

(1.0 kPa)

7.0” w.c.

(1.7 kPa)

10.0” w.c.

(2.5 kPa)

CSA

Maximum

150

(4.2)

150

(4.2)

150

(4.2)

300

(8.5)

300

(8.5)

300

(8.5)

---

1/2 psi

(3.4 kPa)

160

(4.5)

120

(3.4)

100

(2.8)

300

(8.5)

245

(6.9)

225

(6.4)

850

(24.0)

780

(22.0)

650

(18.4)

3/4 psi

(5 kPa)

190

(5.4)

150

(4.2)

120

(3.4)

340

(9.6)

315

(8.9)

270

(7.6)

1060

(30.0)

950

(26.9)

860

(24.4)

Operating Inlet Pressure

1 psi

(7 kPa)

220

(6.2)

180

(5.1)

150

(4.2)

416

(11.8)

340

(9.6)

312

(8.8)

1190

(33.7)

1060

(30.0)

990

(28.0)

2 psi

(13.8 kPa)

220

(6.2)

220

(6.2)

220

(6.2)

500

(14.2)

480

(13.6)

430

(12.2)

1600

(45.3)

1500

(42.5)

1300

(36.8)

/h)

5 psi

(34.5 kPa)

300

(8.5)

290

(8.2)

280

(7.9)

600

(17.0)

600

(17.0)

560

(15.9)

2090

(59.2)

1860

(52.7)

1620

(45.9)

10 psi

(69 kPa)

320

(9.1)

320

(9.1)

320

(9.1)

680

(19.3)

680

(19.3)

680

(19.3)

2190

(62.0)

2060

(58.3)

2060

(58.3)

DIMENSIONS - Expressed in inches (mm)

Model

Number

325-3(B)

325-5A(B) 1/2”, 3/4”, 1”

325-7A(B)

* Standard models NPT threads; ‘M’ models available with BSP threads.

Pipe Size*

3/8”, 1/2”

1 1/4”, 1 1/2”

Swing

Radius

(76)

4 7/8 (124)

6 1/8 (156)

Dimensions

A B C

3 1/2

(89)

5 1/4 (133)

7 1/4 (184)

4 1/4

(108)

5 7/8 (149)

(203)

3 7/8

(98)

5 7/16

(138)

(178)

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.

325-3(B)

325-5A(B)

325-7A(B)

325 Series Appliance Pressure Regulators

SPRING SELECTION CHART - Inches w.c (kPa) unless noted

Model

Number

325-3(B)

325-5A(B)

325-7A(B)

2 psi (13.8 kPa) 5 psi (34.5 kPa)

5 to 9

(1.25 to 2.25)

5 to 9

(1.25 to 2.25)

__ __ __ __

CSA Certied

7 to 11

(1.7 to 2.7)

7 to 11

(1.7 to 2.7)

6 to 10

(1.5 to 2.5)

6 to 10

(1.5 to 2.5)

7 to 11

(1.7 to 2.7)

7 to 11

(1.7 to 2.7)

Standard

Spring

4 to 12

(1.0 to 3.0)

4 to 12

(1.0 to 3.0)

4 to 12

(1.0 to 3.0)

2 to 6

(0.5 to 1.5)

2 to 6

(0.5 to 1.5)

2 to 5

(0.5 to 1.2)

Other Springs Available

10 to 22

(2.5 to 5.5)

10 to 22

(2.5 to 5.5)

10 to 22

(2.5 to 5.5)

15 to 30

(3.7 to 1.5)

15 to 30

(3.7 to 1.5)

15 to 30

(3.7 to 1.5)

1 to 2 psi

(6.9 to 13.9)

1 to 2 psi

(6.9 to 13.9)

20 to 42

(5.0 to 10.4)

SIZING INSTRUCTIONS

When 325 Series regulators are used on 2 psi piping systems, often times the 2 psi systems are sized with a 1 psi pressure drop through the copper or stainless steel tubing. This means there will be 2 psi at the inlet of the regulator under no ow conditions, and 1 psi at the regulator inlet under maximum ow conditions.

TO SELECT AN APPLIANCE REGULATOR OF SUFFICIENT FLOW - ONE MUST KNOW:

1. Available inlet pressure (maximum static/minimum operating).

2. Desired outlet pressure.

3. Required maximum ow rate.

4. Pipe size.

Example: To select a 325 series regulator of sufcient capacity to handle ow...

KNOWN:

A. Desired ow rate 145 CFH.

B. Pipe size 1/2”.

C. Operating inlet pressure 2 psi.

D. Outlet pressure 7” w.c.

E. Lockup required.

SOLUTION:

A. Check pressure drop chart, page 2.

B. The 325-3’s pressure drop at a ow rate of 145 CFH is 7” w.c. This is well below the available differential of 1.75 psi.

C. The 325-3 (1/2”) used with a 5” to 9” spring, set at 7”, is the correct regulator to use for this application.

Maxitrol Company 23555 Telegraph Rd., P.O. Box 2230 Southeld, MI 48037-2230 U.S.A.

APR_MS_EN_09.2011 Replaces 325 LVR_MS_EN

www.maxitrol.com

Maxitrol 325-3(B) User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual