Sterling QVSB - Manual (Page 8)

8
Check all pipe joints for leakage
using a soap solution or other approved method.
Never use an open fl ame or severe personal
injury or death may occur.
Figure 7 - Pipe Installation, Standard Controls
Never use an open flame to
detect gas leaks. Explosive conditions may
exist which would result in property damage,
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 at test pres-
sures 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*
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 gas supply capable of supplying
its full rated capacity as specifi ed in Table 4. A fi eld
LP tank regulator must be used to limit the supply
pressure to maximum of 14 inch W.C. (3.5 kPa). All
piping should be sized in accordance with the lat-
est edition of ANSI Standard Z223.1 National Fuel
Gas Code; in Canada, according to CSA-B149.
See Tables 1, 3 and 4 for correct gas supply 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 take-off piping from the top, or side, of the
main gas pipe.
5. Optional two-stage units are supplied with a
combination valve which includes:
(a) Manual “A” valve (b) Manual “B” valve
(c) Solenoid valve (d) Pilot safety (e) Pressure
regulator
Pipe directly in to combination valve (see Figure 7).
6. A 1/8 inch N.P.T. plugged tapping, accessible
for test gauge connection, must be installed
immediately upstream of the gas supply connection
to the appliance.
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 per mit ser vicing. The
manual main shutoff valve must be located
external to the jacket. See Figure 7.
8. Make certain that all connections have been
adequately doped and tightened.
Do not overtighten the inlet gas
piping into the valve. This may cause stresses
that would crack the valve!
NOTICE: Use pipe joint sealant resistant to the
action of liquefi ed petroleum gases regardless of
gas conducted.
Gas Type
Manifold
Pressure
Supply Inlet
Pressure
Natural Gas
3.5 in. W.C.
(0.9 kPa)
14 in. W.C. Max.
(3.5 kPa)
5.5 in W.C. Min.
(1.4 kPa)
Propane (LP) Gas
10.5 in. W.C.
(2.6 kPa)
14 in. W.C. Max.
(3.5 kPa)
13.0 in W.C. Min.
(3.2 kPa)
*For single stage applications only, at normal altitudes.
D3631C