Form
I-A C (2-17),
Page
9
All piping must be in accordance with requirements outlined in the National Fuel Gas Code
ANSI Z223.1a (latest edition) or CAN/CSA-B149.1 and B149.2 (See Paragraph 1). Gas
supply piping installation should conform with good practice and with the local codes.
Pipe joint compounds (pipe dope) shall be resistant to the action of liquidfied
petroleum gas or any other chemical constituents of the gas being supplied.
Install a ground joint union and manual shutoff valve upstream of the unit control
system as shown in
FIGURE 5
.
The 1/8”plugged tapping in the shutoff valve provides connection for a supply line
pressure test gauge.
The National Fuel Gas Code requires the installation of a trap with a minimum 3” (76 mm)
drip leg. Local codes may require a minimum drip leg longer than 3”, typically 6” (152 mm).
Bleed gas lines of trapped air.
FIGURE 5
-
Supply Piping Connection
WARNING
All components of a gas system must be leak tested prior to
placing equipment in service. NEVER TEST WITH AN OPEN
FLAME. Failure to comply could result in personal injury, property
damage or death.
System pressure cannot be set until the unit is in operation.
For Natural Gas:
The unit is set at the factory to a inlet supply pressure of 7.0 inches
water column. Inlet supply pressure to the valve for natural gas must be a minimum
of 5 inches water column or as noted on the rating plate and a maximum of 14 inches
water column.
For Propane:
The unit can be converted to propane by using a field installed
natural gas to propane kit, Option DL2. Use P/N 1005716 for Model AB 175 or P/N
1005717 for Model AB 225.
Once converted set the pressure to 12.0 inches of water column. Inlet supply pressure
to the valve for propane must be a minimum of 12 inches water column and a maximum
of 14 inches water column.
NOTE:
Before attempting to measure or adjust gas pressure the inlet supply pressure
MUST
be within the specified range both when the air curtain is in operation and on
standby. Incorrect inlet pressure could cause excessive unit pressure immediately or at
some future time. If the natural gas supply pressure is too high, install a lockup-type service
regulator in the supply line before it reaches the unit. If the natural gas supply pressure is
too low, contact your gas supplier.
The gas pressure is set at the factory and should be in compliance to the data noted
on the rating plate and should not require adjustment.
Gas Piping
Requirements and
Connection
Pressure
Settings
Содержание AB 175
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