1-31
BOILER SYSTEMS AND OPERATION
SL 10-85 G3, SL 14-115 G3, SL 20-160 G3, SL 30-199 G3 MODULATING GAS BOILERS
1.7 GAS PIPING
The boiler requires an inlet gas pressure of at least 4.0" w.c. for natural gas or propane.
For either fuel, the inlet pressure shall be no greater than 14.0" w.c. Confirm this pressure
range is available with your local gas supplier.
The inlet gas connection of the boiler’s gas valve is 1/2" NPT (female).
Adequate gas supply piping shall be provided with no smaller than a 1/2" Iron Pipe Size
(e.g. Iron Pipe Size (IPS) and using a 1” w.c. pressure drop, in accordance with the
following chart:
Table 6: Maximum Pipe Length (ft) Schedule 40 steel
NOTE
It is essential to check gas
supply pressure to each
boiler with a manometer or
other high-quality precision
measuring device. Pressure
should be monitored before
firing the boiler, when the
regulator is in a “lock-up”
condition and during operation,
throughout the boiler’s full
modulation range.
Pay special attention to retrofit
situations where existing
regulators may have an over-
sized orifice and/or worn seats,
causing pressure “creep” and
high lock up pressures.
Figure 41: Multiple boiler low loss header piping concept
MODEL
1/2" IPS
3/4" IPS
1" IPS
1-1/4” IPS
SL 10-85 G3/ SL 14-115 G3 (Natural
Gas)
30’
125’
400’
SL 14-115 G3, SL 10-85 G3
(Propane)
90’
350’
1,000’
SL 20-160 G3 (Natural Gas)
10’
70’
200’
SL 20-160 G3 (Propane)
50’
200’
600’
SL 30-199 G3 (Natural Gas)
10’
40’
150’
600’
SL 30-199 G3 (Propane)
30’
125’
400’
1,600’
Summary of Contents for SL 20-160 G3
Page 75: ...6 3 DIAGRAMS SL 10 85 G3 SL 14 115 G3 SL 20 160 G3 SL 30 199 G3 MODULATING GAS BOILERS...
Page 77: ...6 5 DIAGRAMS SL 10 85 G3 SL 14 115 G3 SL 20 160 G3 SL 30 199 G3 MODULATING GAS BOILERS...
Page 79: ...6 7 DIAGRAMS SL 10 85 G3 SL 14 115 G3 SL 20 160 G3 SL 30 199 G3 MODULATING GAS BOILERS...
Page 85: ...SERVICE RECORD DATE LICENSED CONTRACTOR DESCRIPTION OF WORK DONE...
Page 86: ...NOTES...
Page 87: ...NOTES...
