American Dryer Non-Tilting Phase 5 ML-200 - Manual (Page 27)

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3. Piping/Connections
ALL components/materials must conform to National Fuel Gas Code Specifications. It is important that
gas pressure regulators meet applicable pressure requirements and that gas meters be rated for the total
amount of ALL the appliance BTU's being supplied.
The dryer is provided with a 1-1/4" F.P.T. inlet pipe connections extending out of the top of the burner
boxes. The minimum pipe size (supply line) to the dryer is 1-1/2" N.P.T. For ease of servicing, the gas supply
line to each dryer must have its own shut off valve.
The size of the main gas supply line (header) will vary depending on the distance this line travels from the gas
meter or, in the case of L.P. (liquid propane) gas, the supply tank, other gas-operated appliances on the same
supply line, etc. Specific information regarding supply line size should be determined by the gas supplier.
NOTE: Undersized gas supply piping can create a low or inconsistent pressure which will result in
erratic operation of the burner ignition system.
Consistent gas pressure is essential at ALL gas connections. It is recommended that a 1-1/4" (3.18 cm) pipe
gas loop be installed in the gas supply line serving a bank of dryers. An in-line pressure regulator must be
installed in the supply line (header) if the (natural) gas pressure exceeds 12.0 inches of water column (29.9
mb) pressure.
IMPORTANT: A water column pressure of 3.5 inches (8.7 mb) for natural gas and 10.5 inches
(26.1 mb) for L.P. dryers is required at the gas valve pressure tap of each dryer for
proper and safe operation.
A 1/8" N.P.T. plugged tap, accessible for a test gauge connection, must be installed in the main gas supply
line immediately upstream of each dryer.
IMPORTANT: Pipe joint compounds that resist the action of natural and L.P. gases must be used.
IMPORTANT: Test ALL connections for leaks by brushing on a soapy water solution (liquid
detergent works well).
WARNING: NEVER TEST FOR GAS LEAKS WITH A FLAME!!!
ALL components/materials must conform to National Fuel Gas Code Specifications ANSI Z223.1-
LATEST EDITION.
It is important that gas pressure regulators meet applicable pressure requirements, and gas meters be rated
for the total amount of ALL the appliance Btu's being supplied.
IMPORTANT: The dryer and it's individual shut-off valve must be disconnected from the gas supply
piping system during any pressure testing of that system at test pressures in excess of
1/2 psig (3.5 kPa).
NOTE: The dryer must be isolated from the gas supply piping system by closing its individual manual
shut off valve during any pressure testing of gas supply piping system at test pressures equal to
or less than 1/2 psig (3.5 kPa).