Goodman Mfg CVM96 사용자 설명서

32

When gas piping enters directly to the gas valve through the stan-
dard inlet hole, the installer must supply straight pipe with a ground
joint union to reach the exterior of the furnace.  The rigid pipe must
be long enough to reach the outside of the cabinet to seal the
grommet cabinet penetration.  A semi-rigid connector to the gas
piping can be used outside the cabinet per local codes.

When gas piping enters indirectly to the gas valve through the
alternate gas inlet hole the following fittings (starting from the gas
valve) to reach the outside of the cabinet must be supplied:

•

Close nipple.

•

90 degree elbow.

•

2½ inch nipple.

•

90 degree elbow.

•

Straight pipe, with a ground joint union, to reach the exterior
of the furnace.  The rigid pipe must be long enough to reach
the outside of the cabinet so as to seal the grommet cabinet
penetration.  A semi-rigid connector to the gas piping can
be used outside the cabinet per local codes.

Before placing unit in operation, leak test the unit and gas connec-
tions.

Check for leaks using an approved chloride-free soap and water
solution, an electronic combustible gas detector, or other approved
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
pressures in excess of 1/2 psig (3.48 kPa).

Isolate this unit from the gas supply piping system by closing its
external manual gas shutoff valve before pressure testing supply
piping system with test pressures equal to or less than 1/2 psig
(3.48 kPA).

A gas detecting warning system is the only reliable way to detect
a propane gas leak. Rust can reduce the level of odorant in pro-
pane gas.  Do not rely on your sense of smell.  Contact a local
propane gas supplier about installing a gas detecting warning sys-
tem.  If the presence of gas is suspected, follow the instructions
listed in the Safety Precautions section of this manual.

All propane gas equipment must conform to the safety standards
of the National Board of Fire Underwriters, NBFU Manual 58.

For satisfactory operation, propane gas pressure must be 10” WC
+ .5”  WC at the furnace manifold with all gas appliances in opera-
tion. Maintaining proper gas pressure depends on three main fac-
tors:

1. Vaporization rate, depending on temperature of the liquid,

and “wetted surface” area of the container or containers.

2. Proper pressure regulation. (Two-stage regulation is

recommended for both cost and efficiency).

3. Pressure drop in lines between regulators, and between

second stage regulator and the appliance. Pipe size will
depend on length of pipe run and total load of all appliances.

Complete information regarding tank sizing for vaporization, rec-
ommended regulator settings, and pipe sizing is available from
most regulator manufacturers and propane gas suppliers.

Since propane gas will quickly dissolve white lead and most stan-
dard commercial compounds, special pipe dope must be used.
Shellac-based compounds resistant to the actions of liquefied pe-
troleum gases such as Gasolac®, Stalactic®, Clyde’s® or John
Crane® are satisfactory.

Refer to the following illustration for typical propane gas installa-
tions and piping.