Trane Gas Unit Heaters メンテナンスマニュアル
Installation: Piping
18
GLND-SVX01B-EN
Pipe directly in to combination valve (see
5. A 1/8 in. N.P.T. plugged tapping, accessible for test
gauge connection, must be installed immediately
upstream of the gas supply connection to the
appliance.
upstream of the gas supply connection to the
appliance.
6. Provide a drip leg in the gas piping near the gas duct
furnace. A ground joint union and a manual gas shutoff
valve should be installed ahead of the unit heater
controls to permit servicing. The manual main shutoff
valve must be located external to the jacket (see
valve should be installed ahead of the unit heater
controls to permit servicing. The manual main shutoff
valve must be located external to the jacket (see
7.
Make certain that all connections have been
adequately doped and tightened.
adequately doped and tightened.
Note: Use pipe joint sealant resistant to the action of
liquefied petroleum gases regardless of gas
conducted.
conducted.
The appliance and its individual shutoff 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).
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).
The appliance must be isolated from the gas supply piping
system by closing its individual manual shutoff valve
during any pressure testing of the gas supply piping
system at test pressures equal to or less than 1/2 psig
(3.5 kPa).
system by closing its individual manual shutoff valve
during any pressure testing of the gas supply piping
system at test pressures equal to or less than 1/2 psig
(3.5 kPa).
Installation: Venting
ANSI now organizes vented appliances into four
categories.
categories.
Category I
Includes non-condensing appliances with negative vent
pressure, like the traditional atmospheric unit heater.
pressure, like the traditional atmospheric unit heater.
Category II
Groups condensing appliances with negative vent
pressure.
pressure.
Category III
Appliances are non-condensing and operate with a
positive vent pressure.
positive vent pressure.
Category IV
Covers condensing appliances with positive vent
pressure.
pressure.
Note: Category II and IV do not apply to equipment
specified within this manual.
NOTICE:
Overtightening!
Do not overtighten the inlet gas piping into the valve.
This may cause stresses that could crack the valve!
This may cause stresses that could crack the valve!
WARNING
Hazard of Explosion!
Never use an open flame to detect gas leaks. Explosive
conditions may occur. Use a leak test solution or other
approved methods for leak testing. Failure to follow
recommended safe leak test procedures could result in
death or serious injury or equipment or property-only-
damage.
conditions may occur. Use a leak test solution or other
approved methods for leak testing. Failure to follow
recommended safe leak test procedures could result in
death or serious injury or equipment or property-only-
damage.
Figure 10. Pipe installation, standard controls
Table 5.
Gas piping requirements
Gas Type
Natural Gas
Propane (LP) Gas
Single Stage Gas Piping Requirements
(a)
(a) For single stage applications only, at normal altitudes.
Manifold Pressure
3.5 in. wc
10.0 in. wc
(0.9 kPa)
(2.5 kPa)
Supply Inlet Pressure 14.0 in. wc Max.
14.0 in. wc Max.
(3.5 kPa)
(3.5 kPa)
5.0 in wc Min.
11.0 in wc Min.
(1.2 kPa)
(2.7 kPa)
Two Stage Gas Piping Requirements
(b)
(b) For two stage applications only, at normal altitudes.
Supply Inlet Pressure 6.5 in. wc Min.
11.5 in. wc Min.
(1.6 kPa)
(2.9 kPa)
Table 6.
Venting categories
Non Condensing
Condensing
Negative Vent Pressure
I
II
Positive Vent Pressure
III
IV