17
Operations
Inspection and Testing Gas Piping
The building structure should not be weakened by
installing the gas piping. The piping should not be
supported by other piping, but should be firmly
supported with gas hooks, straps, bands or hangers.
Butt or lap welded pipe should not be run through or in
an air duct or clothes chute.
Before turning gas under pressure into piping, all
openings from which gas can escape should be closed.
Immediately after turning on gas, the system should be
checked for leaks. This can be done by watching the
1/2 cubic foot test dial for 5 minutes for any movement
or by soaping each pipe connection and watching for
bubbles. If a leak is found, make the necessary repairs
and repeat the above test.
Defective pipes or fittings should be replaced and not
repaired. Never use a flame or fire in any form to locate
gas leaks — use a soap solution.
After the piping and meter have been checked
completely, purge the system of air. DO NOT bleed the
air inside an enclosed room.
During pressure testing of the system at test pressures
in excess of 1/2 PSIG, the pressure washer and its indi-
vidual shut-off valve must be disconnected from gas
supply piping system or damage to the gas valve will
occur.
Gas Pressure
The ideal incoming gas pressure is 11 w.c.i (water
column inches). Minimum is 9 w.c.i., maximum is 14
w.c.i. or 1/2 PSIG. The correct operating manifold
pressure for natural gas is 2.8 w.c.i. The operating
manifold pressure for propane gas is 7.5 w.c.i. By
adjusting the gas valve pressure regulator between 3
and 4 w.c.i. a side range can be achieved for natural
gas.
If the desired input rating cannot be obtained within the
above manifold pressure adjusting range, then the next
size larger or smaller burner orifice should be used.
The gas pressure coming out of the regulator and going
to the burner ring has been factory set for elevations of
0 to 2000 ft. Altitudes greater than 2000 ft will require
adjustments to the gas manifold pressures. Consult
your local service dealer for high altitude adjustments.
In Canada, certification for installation at altitudes over
4500 feet above sea level is the jurisdiction of local
authorities. You should not readjust the burner ring gas
pressure. If you replace your gas valve, you will need to
adjust the new valve. Refer to your machine’s specifi-
cation plate for the correct pressure setting. Follow the
installation and adjustment instructions provided with
your replacement valve.
NOTE: Air for combustion and ventilation along with
exhaust flue sizing must conform to methods outlined in
current American Standard (ANSI-Z223.1) National
Fuel Gas Code or National Standard of Canada CSA-
149.1 and CSA-149.2 “Installation Code for Gas
Burning Appliances”.
Hotsy 900/1400 Series Dealer Manual 9.803-324.0 - AW
On/Off
Switch
Manifold
Pressure Adjustment
Screw Under Cap