ESAB OXWELD® H-14 & H-16 Back-Pressure Check Valves Troubleshooting instruction

Brand: ESAB

Model: OXWELD® H-14 & H-16 Back-Pressure Check Valves

Type: Troubleshooting instruction

This manual is also suitable for

H-14 & H-16 Back-Pressure Check Valves

F-9615-G

November, 2000

Be sure this information reaches the operator.

You can get extra copies through your supplier.

INSTRUCTIONS for

H-14 & H-16

BACK-PRESSURE

CHECK VALVES

F-9615-G

These INSTRUCTIONS are for experienced operators. If you are not fully familiar

with the principles of operation and safe practices for oxy-fuel gas equipment, we

urge you to read our booklet “Precautions and Safe Practices for Welding, Cut-

ting and Heating,” Form 2035. The same information appears in the “Oxy-Acety-

lene Handbook” which may be purchased from any ESAB distributor. Do NOT

permit untrained persons to operate this equipment. Do NOT attempt to operate

this equipment until you have read and fully understand these instructions. If you

do not fully understand these instructions, contact your supplier for further infor-

mation.

The check valves covered by these instructions are listed by Underwriter’s Labo-

ratories only when using parts manufactured to ESAB Welding & Cutting Prod-

ucts specifications on file with Underwriter’s Laboratories, Inc., and when they

are used in the gas service for which they are designed and listed. The use of

other parts that cause damage or failure to the equipment will void the

manufacturer’s warranty.

SPECIFICATIONS

Back-Pressure Max. Flow Operating

Check Valve For Use Capacity, Pressure Range Inlet Outlet Vent Overall Max.

Model Part No. With CFH (m

/hr) PSL (bars) Connections Connections Connection Height Diameter

I. INTRODUCTION

The OXWELD

H-14 and H-16 Back-Pressure Check

Valves are for station installation at a fuel gas piping

system where oxy-fuel gas equipment is used. The

purpose of these devices is to prevent oxygen backflow,

stop a flashback, and relieve over-pressurization.

NOTE: In compliance with the latest National Fire Pro-

tection Associations (NFPA) Standard No. 58,

the relief valve setting on the check valve

should be set to relieve at 1-1/4 to 2-1/2 times

the piping system pressure. The relief valve

on the H-14 is preset at the factory to relieve

at 20 psig to provide an operating pressure

range of 8 to 15 psig. (Acetylene piping pres-

sure should never exceed 15 psig.) If system

pressure is less than 8 psig, turn the pressure-

adjusting cap on the relief valve counterclock-

wise until the relief valve just starts relieving,

then turn 2 full turns clockwise. The relief valve

should then be set at 1-1/2 times the system

pressure.

The H-16 (P/N 13P16) is equipped with a relief

valve factory preset to relieve at 35 psig, pro-

viding an operating pressure range of 14 to 28

psig per NFPA 58 requirements. This relief

valve (R-29, P/N 11P64) is adjustable for re-

lieving at 25 to 75 psig; therefore the relief valve

should be readjusted if the system pressure is

as low as 10 psig or as high as 60 psig. If sys-

H-14 11P31 Acetylene* 300 (20.7) 8-15 (0.55 -1.0)

H-16 13P16 Fuel Gas* 300 (20.7) 14-28 (1.0 - 1.9)

H-16 2120396 Fuel Gas* 300 (20.7) 50-100 (3.5 - 6.9)

1/2"NPT 1/2" NPT 3/4" NPT 12 - 3/4" 2 - 7/8"

Male Female or Female (323 mm) (73 mm)

CGA-023

* The H-14 is designed for acetylene only. The H-16 is for use with commonly used fuel gases such as natural gas, propane, hydrogen, and propriety fuel gases. It

is not for use with mixtures of acetylene with propane. H-14 and H-16 Back-Pressure Check Valves are not to be used with air-fuel gas mixtures.

Fig. 1 – INSTALLATION SKETCH

tem pressure differs from the specified 14 to

28 psig range, turn the pressure-adjusting cap

on the relief valve until it just starts relieving.

Then turn 2 full turns clockwise. The relief valve

should then be set at 1-1/2 times greater than

the system pressure.

The relief valve on the H-16 (P/N 2120396) is

not adjustable. It is set to relieve at 125 psig;

therefore, the system pressure must be in the

specified range of 50 to 100 psig.

II. INSTALLATION INSTRUCTIONS

IMPORTANT: If the station valve is to be replaced

when an H-14 or H-16 is installed on a supply line which

has previously contained any fuel gas, that part of the

supply line in which the H-14 or H-16 is to be installed

must be completely shut off and isolated from the rest

of the system. The supply line must then be vented

and purged of fuel gas. (Use nitrogen or carbon diox-

ide for purging.)

A. Installation

1. Install the H-14 or H-16 in a vertical position only.

2. Install a moisture trap and vent piping as illustrated

in Figure 1.

Important: Vent piping and fittings must be galvanized

and at least 3/4-inch pipe size. A 3/4-in. street elbow

should be used to connect the vent pipe to the outlet

on the side of the relief valve. The vent pipe must ex-

tend to the outside of the building and terminate not

less than 12 ft. above the ground, remote from win-

dows or openings in the building, and as far as pos-

sible from sources of ignition such as flues or chim-

neys. Its end must be fitted with a return bend or el-

bow opening downward, preferably screened to pre-

vent obstruction. The vent pipe must be installed with-

out traps. The vent pipes from two or more back-pres-

sure check valves supplied through a common branch

of the supply line may be connected to a common vent

pipe header.

B. Test for Leaks

1 Connect a torch with hose to the service outlet of

the H-14 or H-16.

2. Close the torch valves.

3. Be sure there is normal operating pressure in the

supply line.

4. Open the station shutoff valve.

5. Test for leaks around the H-14 or H-16 joints and

also the joints in the supply line. Use leak test so-

lution or soapy water to test for leaks.

6. Eliminate all leaks before equipment at the station

is used.

Never test for leaks with an open flame.

III. OPERATING INSTRUCTIONS

1. Make sure the torch valves are closed then pres-

surize the H-14 or H-16 with normal fuel gas pres-

sure by opening the station shutoff valve.

2. Operate the torch in the usual manner.

Note: The hose connected to the H-14 and H-16

should not exceed 100 feet in length or 13/16-

inch inside diameter.

3. To shut off the H-14 or H-16, close the torch valves

and close the station shutoff valve.

4. The H-14 and H-16 can be operated at flow rates

greater than 300 cu. ft. per hr., however higher pres-

sure drop will occur across the unit (see Pressure

Drop Chart).

0.5

1.5

2.5

0 50 100 150 200 250 300

Flow CFH

Pressure

Drop

PSIG

Fig. 2 - Pressure Drop Chart

30 LB. GAUGE

1/4” N.P.T. PIPE

COUPLING

CONNECTION — 3390

1/4-IN. FUEL GAS

HOSE WITH

STANDARD FITTINGS;

LENGTH AS DESIRED

Fig. 3 – TEST GAUGE HOOK-UP

5. The H-14 and H-16 protective devices incorporate

a feature that stops fuel flow when subjected to

flows substantially above the devices rated capac-

ity. When this condition happens the rubber sleeve

is forced against the outer wall of the device pre-

venting fuel flow. If this happens, turn off fuel sup-

ply pressure to the H-14 or H-16, bleed the fuel

gas pressure from the torch by momentarily open-

ing then closing the fuel gas valve at the torch,

then slowly turn on fuel supply pressure. If normal

operation is not restored when the flow is at maxi-

mum capacity or less, do the following.

Make sure fuel gas supply pressure is no higher

than maximum allowable settings and try torch

operation again (H-14 acetylene - 15 psig), (H-16

other fuel gasses - 200 psig). If normal fuel flow

and torch operation are restored no further

action is required. If fuel flow is not restored the

unit must be disassembled, the rubber sleeve re-

turned to its position on the mandrel, and reas-

sembled. The H-14 or H-16 can then be returned

to service (see Sec. V, Maintenance Instructions).

Important: If a flashback occurs, immediately close

the torch oxygen valve and then the torch

fuel gas valve. Wait about one minute -

then resume operation. If a flashback re-

occurs stop operation immediately and re-

place the torch.

IV. PERIODIC INSPECTION

The following inspection should be made regularly in

order to obtain safe and reliable service:

1. Regularly drain the moisture trap.

A. Close the station shutoff valve and lift the re-

lief valve operating lever.

B. Remove the drain cap and let all water run out.

Using Teflon tape or suitable pipe-compound

on the male thread, promptly replace the drain

cap.

2. Every two weeks operate the Relief Valve. Lift

the valve operating lever for an instant to unseat

the valve. This guards against sticking of the valve.

3. Every six months inspect the H-14 or H-16 for

leakage and the condition of the rubber sleeve

as follows:

A. Preparation

a. Test for leaks to the atmosphere as instructed

in II-B.

b. Attach a 30 psig pressure gauge to the outlet

connection. (See Fig. 3.)

B. Testing

a Crack the shutoff valve very slightly to allow

the pressure to build up to 5 psig, then close

the valve tight.

b. Watch the pressure gauge for several minutes.

If the pressure falls, inspect the relief valve as

outlined in F-9373, Instructions and Parts List

for RV-27, 28, and 29 Relief Valves (packed

with H-14 and H-16).

c. Loosen the pipe union on the relief valve vent

piping one or two turns. Then slowly loosen

the pipe union between the shutoff valve and

the H-14 or H-16 to relieve the pressure from

the inlet piping. Uncouple this pipe union and

rotate the H-14 or H-16 and its connected pip-

ing, in its supporting clamp, enough to move

the union 1/8 turn forward. Watch the pres-

sure gauge to make sure the 5 psig has been

maintained. Check the rubber sleeve for

backflow leakage with a film of leak test solu-

tion or soapy water across the union face. If

no leakage is observed, reassemble the pip-

ing operate the relief valve, and remove the

pressure gauge. If there is leakage, the cause

should be corrected as outlined in Section V,

Maintenance Instructions.

V. MAINTENANCE INSTRUCTIONS

A. Before taking any action to repair, adjust, or disas-

semble the H-14 or H-16, or its relief valve, be sure

you have closed the station shutoff valve in the

supply line and relieved all pressure.

B. Make no repairs or replacements other than those

described below. When installing new parts, use

only genuine OXWELD

parts shown on the back

page.

F-9615-G 11/2000 Printed in U.S.A.

C. To inspect and clean the rubber sleeve, sealing

ring, and the inlet filter, proceed as follows:

Wear Safety Goggles. Never use Oxygen in Place

of Compressed Air.

1. Close the station shutoff valve, operate the relief

valve to relieve the pressure, and disconnect the

hose from the outlet.

2. Disconnect the pipe unions in the inlet and the vent

piping.

3. Disconnect the pipe and the elbow at the check

valve inlet.

4. Remove the filter and clean it thoroughly with a jet

of clean compressed air or nitrogen. If clean com-

pressed air is not available, wash the filter thor-

oughly in clear water.

5. Wipe out the filter retaining recess with a clean

cloth.

6. Loosen the cap with a pipe wrench. Slowly unscrew

the cap and remove the pressure ring, seal ring,

mandrel, and rubber sleeve. Handle the mandrel

with care. Place the mandrel on a clean cloth or in

a spare rubber sleeve to prevent the raised seat-

ing rings from being nicked or damaged.

7. Remove any grit or dirt from the rubber sleeve,

mandrel, and housing. If it is necessary to blow

the dirt out, use clean compressed air or nitrogen.

8. Inspect and clean the relief valve. Follow the in-

structions in F-9373, Instructions for RV-27, 28,

and 29 Relief Valves, packed with the H-14 or H-

16.

9. Remove the outlet connection while the relief valve

is disconnected, pull out the ball-check retaining

pin, and remove the ball check. Clean the ball-

check and its recess with a clean cloth.

10. Reassemble the H-14 or H-16 replacing any worn

parts with new parts.

11. Leak test the check valve for backflow as outlined

in Section IV, Periodic Inspection.

12. Test the entire station for leaks. See Section II-B,

INSTALLATION INSTRUCTIONS.

PRESSURE-ADJUSTING CAP

(11P63 & 11P64 ONLY)

PIN  64S07

SLEEVE  64S12

CAP  73S93

SEAL RING  64S17

RING  64S15

FILTER  25R93

MANDREL  23R30

BALL  7203-5050

(1/2 Stainless Steel)

RELIEF VALVE -

11P63 (H14)

11P64 (H-16, P/N 13P16)

22X56 (H-16, P/N 2120396)

PARTS SUPPLIED:

Adaptor, 1/2 PT x 9/16 - 18 LH male  8693

Plug & Chain Assembly  86W41

OXWELD is a registered trademark of ESAB Welding & Cutting Products.

ESAB OXWELD® H-14 & H-16 Back-Pressure Check Valves Troubleshooting instruction

Brand: ESAB

Model: OXWELD® H-14 & H-16 Back-Pressure Check Valves

Type: Troubleshooting instruction

This manual is also suitable for

H-14 & H-16 Back-Pressure Check Valves

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ESAB OXWELD® H-14 & H-16 Back-Pressure Check Valves Troubleshooting instruction

This manual is also suitable for

ESAB OXWELD® H-14 & H-16 Back-Pressure Check Valves Troubleshooting instruction

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