PIPE INSTALLATION
1.Install the gas piping in accordance with applicable local codes.
2.Check gas supply pressure. Each unit heater must be connected to a manifold pressure and a gas supply capable of supplying its full rated capacity as specified in Table 4. A field LP tank regulator must be used to limit the supply pressure to a maximum of 14 in. W.C. (3.5 kPa). All piping should be sized in accordance with the latest edition of ANSI Standard Z223.1, National Fuel Gas Code; in Canada, according to CGA B149. See Tables 1 & 3 for correct gas piping size. If gas pressure is excessive on natural gas applications, install a pressure regulating valve in the line upstream from the main shutoff valve.
3.Adequately support the piping to prevent strain on the gas manifold and controls.
4.To prevent the mixing of moisture with gas, run the
5.Standard Unit Heaters, optional
a.Manual "A" valve
b.Manual "B" valve
c.Solenoid valve
d.Pressure regulator
Pipe directly into the combination valve (see Figure 4).
6.Gas valve has a pressure test post requiring a 3/32" hex head wrench to read gas supply and manifold pressures. Open 1/4 turn counterclockwise to read, turn clockwise to close and reseat. A 5/16" ID hose fits the pressure post.
7.Provide a drip leg in the gas piping near the gas unit heater. A ground joint union and a manual gas shutoff valve should be installed ahead of the unit heater controls to permit servicing. The manual shutoff valve must be located external to the jacket (See Figure 4).
8.Make certain that all connections have been adequately doped and tightened.
Do not over tighten the inlet gas piping into the valve. This may cause stresses that will crack the valve!
NOTICE: Use pipe joint sealant resistant to the action of liquefied petroleum gases regardless of gas conducted.
Check all pipe joints for leakage using a soap solution or other approved method. Never use an open flame or severe personal injury or death may occur!
Figure 4 - Pipe Installation, Standard Controls
Never use an open flame to detect gas leaks. Explosive conditions may exist which may result in personal injury or death!
The appliance and its individual shutoff valve must be disconnected from the gas supply piping system during any pressure testing of that system 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).
Table 4 - Gas Piping Requirements
SINGLE STAGE GAS PIPING REQUIREMENTS*
GasType | Natural Gas | Propane (LP) Gas | |
Manifold | 3.5 in. W.C. | 10.0 in. W.C. | |
Pressure | (0.9 kPa) | (2.5 kPa) | |
|
|
| |
| 14.0 in. W.C. Max. | 14.0 in. W.C. Max. | |
Supply Inlet | (3.5 kPa) | (3.5 kPa) | |
Pressure |
|
| |
5.0 in. W.C. Min. | 11.0 in W.C. Min. | ||
| |||
| (1.2 kPa) | (2.7 kPa) |
*For single stage application only at normal altitudes.
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