GMS8 Installation Manual

20
aluminum-alloy tubing and connectors are coated to
protect against external corrosion when in contact
with masonry, plaster, or insulation, or subjected to
repeated wetting by liquids such as water (except rain
water), detergents, or sewage.
Drip Le g
Ground Joint Pipe Union
To Be In st a l led
Ahead of Gas Valve
OPTIONAL:
Reducing Coupling
1/ 2” x 1/ 8” with 1/ 8”
Pipe Plug to Measure
Line Gas Pressure
Height Required
By Local Code
Location of Manual Valve
(Installed Ahead of
Ground Joint Pipe Union)
General Furnace Layout
UPFLOW INSTALLATIONS
A ground joint union, drip leg, and manual shutoff valve must
also be supplied by the installer. In some cases, the installer may
also need to supply a transition piece from 1/2" to another pipe
size.
When the gas piping enters through the side of the furnace, the
installer must supply the following fittings (starting from the gas
valve nipple elbow):
• Straight pipe to reach the exterior of the furnace.
• A ground joint union, drip leg, and manual shutoff valve
must also be supplied by the installer.
COUNTERFLOW INSTALLATIONS
When the gas piping enters through the left side of the furnace,
the installer must supply the following fittings, starting at the
gas valve:
- Nipple
- Elbow
- Straight pipe to reach the exterior of the furnace
A ground joint union, drip leg and manual shutoff valve must also
be supplied by the installer. In most cases, the installer may also
need to supply a transition piece from ½” to another pipe size.
GAS PIPING CHECKS
Before placing unit in operation, leak test the unit and gas connec-
tions.
T O AVOID THE POSSIBILITY OF EXPLOSION OR FIRE , NEVER USE A M ATCH
OR OPEN FLAM E TO TEST FOR LEAKS .
WARNING
Check for leaks using an approved chloride-free soap and water
solution, an electronic combustible gas detector, or other ap-
proved testing methods.
NOTE: Never exceed specified pressures for testing. Higher
pressure may damage the gas valve and cause subsequent
overfiring, resulting in heat exchanger failure.
Disconnect this unit and shutoff valve from the gas supply piping
system before pressure testing the supply piping system with pres-
sures in excess of 1/2 psig (3.48 kPa).
This unit must be isolated from the gas supply system by closing
its manual shutoff valve before pressure testing of gas supply
piping system with test pressures equal to or less than 1/2 psig
(3.48 kPa).