27
Consistent gas pressure is essential at
ALL
gas connections. It is recommended that a 3/4-inch pipe gas
loop be installed in the supply line serving a bank of dryers. An in-line pressure regulator
must be
installed
in the gas supply line (header) if the (natural) gas pressure exceeds 12.0 inches of water column (30 mbar)
pressure. Refer to the illustrations on the
previous page
(
page 26
).
NOTE
: A water column test pressure of 3.5 inches (8.7 mbar) for natural gas and 10.5 inches (26.2
mbar) for L.P. (liquid propane) 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 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!!!
ALL
components/materials
must conform
to National 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.
IMPORTANT
: The dryer and its 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 test of the gas supply system at test pressures equal to or less
than 1/2 psig (3.5 kPa).