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Part 8 - Gas Connections
C. Additional Precaution for Excess Flow Valve (EFV)
If an excess flow valve (EFV) is in the gas line, check the manufacturer’s
minimum and maximum flow capacity ratings. An improperly sized
EFV will not allow for a full flow of gas to the boiler and will cause the
boiler to malfunction. See Figure 57.
D. Checking Gas Pressure at the Boiler for Proper
Operation
NOTE: Refer to Figures 58 and 59 when checking gas pressure. Loosen
the bolts before checking the gas inlet pressure.
1. The boiler and its individual shutoff valve must be disconnected
from the gas supply piping system during any pressure testing of
the system at test pressures greater than ½ psi (3.5 kPa).
2. The boiler must be isolated from the gas supply piping system by
closing its individual manual shutoff valve during any pressure
testing of the gas supply piping system at test pressures equal to or
less than ½ psi (3.5 kPa).
The minimum and maximum inlet gas line pressures must meet the
requirements shown in Table 22.
Natural Gas
Minimum Pressure 3.5” WC
Maximum Pressure 10.5”WC
LP Gas
Minimum Pressure 8” WC
Maximum Pressure 13”WC
Table 22 - Gas Pressure Requirements
4
2
1
Gas Inlet
1. Line pressure Test point
2. OFFSET Adjustment Screw
4. Throttle Adjustment Screw
Figure 57 - Excess Flow Valve (EFV)
Figure 58 - Remove Yellow Cap
When performing a pressure test on the gas line pipng, be sure the boiler
is disconnected or isolated if the test pressure is expected to exceed 1/2
PSI (14” WC), as damage to the gas valve could occur. Such damage
could result in fire, property damage, serious personal injury, or death.
DO NOT REMOVE OR ATTEMPT TO MAKE AN
ADJUSTMENT TO SCREWS 2 and 4 WITHOUT A
CALIBRATED COMBUSTION ANALYZER. DOING SO
COULD RESULT IN FIRE, PROPERTY DAMAGE, SERIOUS
PERSONAL INJURY, OR DEATH.
WARNING
WARNING
Do not fire (operate) the boiler until all connections have been
completed and the heat exchanger is filled with water. Doing so will
damage the boiler and void the warranty.
NOTICE
7. Use a manometer to test the gas pressure to make sure it meets the
minimum standards and does not exceed the maximum standards
of the boiler.
8. Leak test the gas line pipe before placing the boiler in operation.
Only use approved leak detector liquid solutions to check for leaks.
9. Do not operate the boiler until all connections have been completed
and the heat exchanger is filled with water.
To check inlet gas pressure:
1. Remove yellow cap from line pressure test point. See Figure
58.
2. Unscrew “P in” screw.
3. Connect the manometer to the test point.
4. Check the inlet gas pressure.
5. Disconnect the manometer from the test point.
6. Tighten the “P in” screw (1 N/m).
7. Check for and repair any gas leaks.
8. Replace the yellow cap.
Gas Outlet
Figure 59 - Gas Valve Detail