lp-445-r4 Rev. 006 Rel. 027 Date 7.21.20
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A. Gas Piping
1. Run the gas supply line in accordance with all applicable codes.
2. Locate and install manual shutoff valves in accordance with state
and local requirements.
3. In Canada, the Manual Shutoff must be identified by the installing
contractor.
4. It is important to support gas piping as the unit is not designed to
structurally support a large amount of weight.
5. Purge all gas lines thoroughly to avoid start up issues with air in
the lines.
6. Sealing compound must be approved for gas connections. Care
must be taken when applying compound to prevent blockage or
obstruction of gas flow which may affect the operation of the unit.
Support gas supply piping with hangers, not by the boiler or its
accessories. The boiler gas valve and blower will not support the
weight of the piping. Make sure the gas piping is protected from
physical damage and freezing, where required. Failure to follow
these instructions could result in gas leakage, and result in fire,
explosion, property damage, severe personal injury, or death.
Do not use Teflon tape on gas line pipe thread. Use a pipe
compound rated for use with natural and propane gases. Apply
sparingly on male pipe ends, leaving the two end threads bare
and flow unobstructed. Failure to follow these instructions could
result in gas leakage or blockage, and result in fire, explosion,
property damage, severe personal injury, or death.
Figure 28 - Gas Connection
The gas connection on the boiler is 1 1/2” for the 500 model and 2”
for the 700/850 models. It is mandatory that this fitting is used for
connection to a field fabricated drip leg as shown in the illustration
per the National Fuel Gas Code. You must ensure that the entire
gas line to the connection at the boiler is no smaller than the unit
supplied connection.
Once all inspections have been performed, the piping must be leak
tested. If the leak test requirement is a higher test pressure than
the maximum inlet pressure, you must isolate the boiler from the
gas line. In order to do this, shut the gas off using factory and field-
installed gas cocks. This will prevent high pressure. Failure to do so
may damage the gas valve. In the event the gas valve is exposed to
a pressure greater than ½ PSI, 14” w.c. (3.5 kPa), the gas valve must
be replaced. Never use an open flame (match, lighter, etc.) to check
gas connections.
Never use an open flame (match or lighter) to check for gas leaks. Use
a soapy solution to test connection. Failure to use a soapy solution
test or check gas connection for leaks can result in substantial
property damage, severe personal injury, or death.
Use two wrenches when tightening gas piping at the boiler: One to
prevent the boiler gas line from turning. Failure to prevent the boiler
gas connection from turning could result in damage to the gas line
components, substantial property damage, severe personal injury,
or death.
CSA or UL listed flexible gas connections can be used when installing
the boiler. Flexible gas connections have different capacities
and must be sized correctly for the connected boiler firing rates.
Consult with the flex line supplier to assure the line size is adequate
for the job. Follow local codes for proper installation and service
requirements.
B. Gas Table
Refer to Table 14 to size the supply piping to minimize pressure drop
between the meter or regulator and unit. Maximum capacity of pipe
in cubic feet of gas per hour for gas pressures of .5 w.c. or less and a
pressure drop of .3 inch w.c.
Natural Gas Supply Piping Capacity Chart
(0.6 Specific gravity gas; 0.5” WC pressure drop)
*Schedule 40 iron pipe size in nominal inches
Cubic Ft. Hr.
500
1000
1500
2000
2500
3000
3500
4000
Model
1 Boiler
2 Boilers
3 Boilers
4 Boilers
5 Boilers
6 Boilers
7 Boilers
8 Boilers
500 @ 100’ of
Pipe
1 1/2”
2”
2 1/2”
3”
3”
3”
4”
4”
500 @ 250’ of
Pipe
2”
2 1/2”
3”
3”
4”
4”
4”
4”
Cubic Ft. Hr.
700/850
1400/1700
2100/2550
2800/3400
3500/4250
4200/5100
4900/5950
5600/6800
Model
1 Boiler
2 Boilers
3 Boilers
4 Boilers
5 Boilers
6 Boilers
7 Boilers
8 Boilers
700/850 @ 100’
of Pipe
2”
2 1/2”
3”
4”
4”
4”
4”
5”
700/850 @ 250’
of Pipe
2 1/2”
3”
4”
4”
5”
5”
5”
5”
Table 14 - Gas Supply Piping Size Chart for Boilers
