OP
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-inch 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 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 water column pressure
(29.2 mb.) Refer to the illustration on the following page [page 24] 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-inch 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).