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

Type
Troubleshooting instruction

This manual is also suitable for

ESAB H-14 & H-16 Back-Pressure Check Valves are designed to prevent oxygen backflow, stop flashbacks, and relieve over-pressurization in oxy-fuel gas systems. They are suitable for use with acetylene, fuel gases like natural gas, propane, and hydrogen, but not for air-fuel gas mixtures. The H-14 model is specifically designed for acetylene, while the H-16 is for other fuel gases. Both models have a maximum flow capacity of 300 CFH (20.7 m3/hr) and are equipped with a pressure-adjustable relief valve for added safety.

ESAB H-14 & H-16 Back-Pressure Check Valves are designed to prevent oxygen backflow, stop flashbacks, and relieve over-pressurization in oxy-fuel gas systems. They are suitable for use with acetylene, fuel gases like natural gas, propane, and hydrogen, but not for air-fuel gas mixtures. The H-14 model is specifically designed for acetylene, while the H-16 is for other fuel gases. Both models have a maximum flow capacity of 300 CFH (20.7 m3/hr) and are equipped with a pressure-adjustable relief valve for added safety.

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 Underwriters Labo-
ratories only when using parts manufactured to ESAB Welding & Cutting Prod-
ucts specifications on file with Underwriters 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
manufacturers 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
3
/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.
2
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
0.5
1
1.5
2
2.5
0 50 100 150 200 250 300
Flow CFH
Pressure
Drop
PSIG
Fig. 2 - Pressure Drop Chart
3
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.
  • Page 1 1
  • Page 2 2
  • Page 3 3
  • Page 4 4

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

Type
Troubleshooting instruction
This manual is also suitable for

ESAB H-14 & H-16 Back-Pressure Check Valves are designed to prevent oxygen backflow, stop flashbacks, and relieve over-pressurization in oxy-fuel gas systems. They are suitable for use with acetylene, fuel gases like natural gas, propane, and hydrogen, but not for air-fuel gas mixtures. The H-14 model is specifically designed for acetylene, while the H-16 is for other fuel gases. Both models have a maximum flow capacity of 300 CFH (20.7 m3/hr) and are equipped with a pressure-adjustable relief valve for added safety.

Ask a question and I''ll find the answer in the document

Finding information in a document is now easier with AI