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X-PV
Installation, Operating & Service Manual
8
Gas Piping
WARNING
• Shut off gas supply before servicing the boiler.
• All gas piping must be gas tight. Use thread
compound that is listed for gas service on all
threaded joints to avoid leaks, which may result
in fire or explosion.
• Size gas piping, regulators, valves and meters
so as to provide an adequate gas flow
and pressure to the boiler during operation.
Failure to do so may cause poor combustion,
noise, injury or death.
!
Figure 8.1: Gas Connection To Boiler
1. Size gas piping - Design system to provide
adequate gas supply to boiler. Consider these
factors:
a. Allowable pressure drop from point of
delivery to boiler. Maximum allowable system
pressure is ½ psig. Actual point of delivery
pressure may be less; contact gas supplier for
additional information. Minimum gas valve inlet
pressure is listed on rating label.
b. Maximum gas demand. Consider existing and
expected future gas utilization equipment (i.e.
water heater, cooking equipment).
2. Connect boiler gas valve to gas supply system -
a. Use methods and materials in accordance
with local plumbing codes and requirements
of gas supplier. In absence of such
requirements, follow
National Fuel Gas Code,
ANSI Z223.1/NFPA 54.
b. Use thread compounds (pipe dope) resistant
to action of liquefied petroleum gas.
c. Install sediment trap, ground-joint union and
manual shut-off valve upstream of boiler gas
control valve. See Figure 8.1.
d. All above ground gas piping upstream from
manual shut-off valve must be electrically
continuous and bonded to a grounding
electrode. Do not use gas piping as grounding
electrode. Refer to
National Electrical Code,
ANSI/NFPA 70.
3. Pressure test - Boiler and its gas connection must
be leak tested before placing boiler in operation.
a. Protect boiler gas control valve. For all testing
over ½ psig, boiler and its individual shutoff
valve must be disconnected from gas supply
piping. For testing at ½ psig or less, isolate
boiler from gas supply piping by closing
boiler's individual manual shutoff valve.
b. Locate and address leaks using listed
combustible gas detector, a non corrosive leak
detection fluid or other listed leak detection
method. Do not use matches, candles, open
flames, or other ignition source.
DANGER
Explosion Hazard. Do not use matches,
candles, open flames or other ignition source to
check for leaks.
!
