PB Heat 211A - Manual (Page 32)

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CONNECT GAS PIPING
c. When piping bleed lines to outside, terminate the
tubing downward to prevent water from entering
the tubing, and protect the tubing termination
from any obstruction. Terminate the tubing
above and well away from normal breathing
level or building air intakes.
D. INSTALL GAS SUPPLY PIPING
1. Size the piping as required by the National Fuel Gas
Code, ANSI Z223.1/NFPA 54 and/or CAN/CGA
B149 Installation Codes or as required by local
codes.
a. Use Table 7.1 for sizing of natural gas for a
system pressure drop of 0.3 inch water
column (75 Pa).
2. The standard gas train is designed for a maximum
pressure of 1/2 psig (14 inches water column/3.5 kPa).
Make sure the system regulator will not allow a higher
pressure to the Gas Control Train under any
conditions.
3. The minimum gas supply pressure is listed on the
Boiler Rating Label. Make sure the system regulator
and the piping are sized and adjusted properly to
provide this pressure under all conditions.
4. Install a Service Valve, Sediment Trap and Ground
Joint Union at the supply connection to the Gas
Control Train as shown in Figure 7.2. These are not
supplied with the boiler. Install them in accordance
with local codes.
5. Use only pipe joint compounds rated for use with
Liquefied Petroleum Gases. This is necessary
because most natural gas contains propane as well
as methane.
E. TEST GAS SUPPLY PIPING
1. ISOLATE THE BOILER GAS CONTROL TRAIN
FROM THE SYSTEM DURING TEST:
a. Test pressure 1/2 psig (3.5 kPa) or less – Close
the Manual Shut-Off Valve on the Boiler Gas
Control Train
b. Test pressure over 1/2 psig (3.5 kPa) – Disconnect
the gas supply piping upstream of the Boiler
Manual Shut-Off Valve
Do not expose the Gas Control Train to excessive
pressure. The gas valves can be damaged. This could
result in explosion hazard and severe personal injury
or death.
Do not test gas supply piping with open flame. Use a
soap suds mixture brushed onto the pipe joints to
test for leaks.
WARNING
Figure 7.2: Gas Supply Connection to Boiler