American Dryer Corp. AD-236, Installation Manual

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3. Piping Connections
ALL components/materials must conform to National Fuel Gas Code Specifications ANSI Z223.1-LATEST
EDITION, or in Canada, CAN/CGA-B149.1-M91 (Natural Gas) or CAN/CGA-B149.2-M91 (Liquid
Propane [L.P.] Gas) or LATEST EDITION (for General Installation and Gas Plumbing), as well as local
codes and ordinances and must be done by a qualified professional. 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 BTUs being supplied.
The dryer is provided with a 3/4” N.P.T. inlet pipe connection located at the upper right hand corner (when
viewed from the rear) of the dryer. The minimum pipe size (supply line) to the dryer is 3/4” N.P.T. For
ease of servicing, the gas supply line of each dryer must have its own shutoff 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. gas, the supply tank, the number of tees, other gas operated appliances on
the 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 3/4-inch (19.05
mm) pipe loop be installed in the supply line servicing the bank of dryers. An in-line pressure regulator
must be installed in the gas supply line (header) if (natural) gas line pressure exceeds 12.0 inches (29.9
mb) water column (W.C.) pressure. (Refer to the illustrations on the following page for details.)
IMPORTANT: Water column pressure of 3.5 inches (8.7 mb) for natural gas dryers and 10.5 inches
(26.1 mb) for L.P. gas is required at the gas valve pressure tap of each dryer for
proper and safe operation.
An 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 gas and L.P. gas must be used.
IMPORTANT: Test ALL connections for leaks by brushing on a soapy water solution (liquid
detergent works well).
WARNING: NEVER TEST FOR LEAKS WITH A FLAME!!!
IMPORTANT: The dryer and its individual shutoff 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
shutoff valve during any pressure test of the gas supply system at test pressures equal to or less
than 1/2 psig (3.5 kPa).