28
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 two (2) 3/4” N.P.T. inlet pipe connections (one [1] for each basket [tumbler]) at
the rear of the dryer. If a separate feed is provided for each basket (tumbler) from the main supply line
(header), then a 3/4” line connection is sufficient. However, if the top basket (tumbler) and the bottom
basket (tumbler) are connected together, the supply from this connection to the header
must be
a minimum
of 1-inch (2.54 cm) and
must not exceed
50 feet (15.24 meters). For typical gas connections, refer to the
illustration
on
page 29
. It is recommended that a gas shutoff valve be provided to the gas supply line of
each dryer basket (tumbler) for ease in servicing.
The size of the gas supply line (header) will vary, depending on the distance this supply line travels from the
gas meter (or in 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 gas 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 3/4” (19.05 cm) 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) of water
column (W.C.) pressure. Refer to the
illustration
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.
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.
WARNING:
Test
ALL
connections for leaks by brushing on a soapy water solution (liquid detergent
works well).
WARNING: NEVER TEST FOR LEAKS WITH A FLAME!!!
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 (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.
