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B. Gas Table
Refer to Table 13 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
Model
1 Unit
1000 @ 100' of Pipe
2"
1000 @ 250' of Pipe
2 1/2"
Model
1 Unit
1700 @ 100' of Pipe
2 1/2"
1700 @ 250' of Pipe
3"
Table 13 - Gas Supply Piping Size Chart for Boilers
C. Check Inlet Gas Pressure
The gas valve is equipped with an inlet gas pressure tap that can be
used to measure the gas pressure to the unit. To check gas pressure,
perform the steps listed below:
1. IMPORTANT! Before you connect to the inlet pressure, shut off the
gas and electrical power to unit.
2. Loosen the pressure tap with a small screwdriver. Refer to Figures 29
and 30 for location.
3. Each unit is equipped with a needle valve that will accept a 5/16 ID
hose to connect to a digital manometer or liquid gauge to measure
incoming pressure from 0-35" w.c.
4. Turn on the gas and power up the unit.
5. Put the unit into manual test mode (details on test mode in Part 10).
In test mode, monitor pressure to assure it does not drop below 1 inch
from its idle reading. If gas pressure is out of range or pressure drop
is excessive, contact the gas utility, gas supplier, qualified installer, or
service agency to determine correct action that is needed to provide
proper gas pressure to the unit. If Gas Pressure is within normal range
proceed to Step 6.
6. Exit test mode, then turn power off and shut off gas supply at
the manual gas valve before disconnecting the hose from the gas
monitoring device. Tighten screw on the pressure tap and turn gas on.
Check for leaks with soapy solution. Bubbles will appear on the pipe to
indicate a leak is present.
Ensure the pressure tap screw is properly tightened to prevent gas
leaks. Failure to do so could cause substantial property damage,
severe personal injury, or death.
The gas piping must be sized for the proper flow and length of pipe
to avoid pressure drop. The gas meter and regulator must be properly
sized for the total gas load. If you experience a pressure drop greater
than 1" w.c. (.87 kPa), the meter, regulator or gas line may be undersized
or in need of service. You can attach a manometer to the incoming
gas drip leg after removing the cap. The gas pressure must remain
between 3.5" (.87 kPa) and 14" (3.5 kPa) during stand-by (static) mode
and while in operating (dynamic) mode.
If an in-line regulator is used, it must be a minimum of 10 feet from the
boiler. It is very important that the gas line is properly purged by the
gas supplier or utility. Failure to properly purge the lines, or improper
line sizing, will result in ignition failure. This problem is especially
noticeable in NEW LP installations and empty tank situations. This
situation can also occur when a utility company shuts off service to an
area to provide maintenance to their lines. This gas valve must not be
replaced with a conventional gas valve under any circumstances.
2 Units
3 Units
4 Units
3"
3"
4"
3"
4"
4"
2 Units
3 Units
4 Units
4"
4"
5"
4"
5"
5"
DO NOT adjust or attempt to measure gas valve outlet pressure.
The gas valve is factory-set for the correct outlet pressure and
requires no field adjustment. Attempts by the installer to adjust or
measure the gas valve outlet pressure could result in damage to
the valve and cause substantial property damage, severe personal
injury, or death.
Strain on the gas valve and fittings may result in vibration,
premature component failure and gas leakage, and result in fire,
explosion, property damage, severe personal injury, or death.
Adjustments to the throttle screw or offset may only be made by
a qualified gas technician using a calibrated combustion analyzer
capable of measuring CO2 and CO. Failure to follow this instruction
could result in fire, explosion, property damage, severe personal
injury, or death.
Ensure that the high gas pressure regulator is as least 6 – 10
feet upstream of the appliance. Failure to do so could result in
substantial property damage, severe personal injury, or death.
Do not do a gas conversion on this boiler without an officially
approved
conversion
kit
Westinghouse. Failure to use a conversion kit when converting
the boiler to fire on Natural or Propane gas will result in extremely
dangerous burner operation, leading to fire, explosion, severe
personal injury, or death.
Natural or LP Gas
Minimum Pressure
Maximum Pressure
Table 14 - Gas Pressure Requirements
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.
whl-428-r1 Rev. 001 Rel. 012 Date 7.21.20
and
instructions
supplied
3.5" WC
14"WC
37
by
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