Gas Piping - Weil-McLain Ultra 3 series User Manual

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gas fired water boiler

Gas piping

Connecting gas supply piping
1. Remove jacket front panel and refer to
boiler.
a. Install ground joint union for servicing, when required.
b. Install manual shutoff valve in gas supply piping outside boiler
jacket when required by local codes or utility requirements.
c. In Canada — When using manual main shutoff valve, it must
be identified by the installer.
2. Wall-mounted boilers
a. Refer to separate Ultra Boiler Wall-mounting instructions.
b. Gas connection may enter from the bottom of boiler as ex-
plained in the Wall-mounting instructions.
3. Support piping with hangers, not by boiler or its accessories.
4. Purge all air from gas supply piping.
5. Before placing boiler in operation, check boiler and its gas con-
nection for leaks.
a. Close manual main shutoff valve during any pressure testing
at less than 13" w.c.
b. Disconnect boiler and gas valve from gas supply piping during
any pressure testing greater than 13" w.c.
Do not check for gas leaks with an open flame — use
bubble test. Failure to use bubble test or check for gas
leaks can cause severe personal injury, death or substan-
tial property damage.
6. Use pipe dope compatible with propane gases. Apply sparingly
only to male threads of pipe joints so that pipe dope does not
block gas flow.
Failure to apply pipe dope as detailed above can result
in severe personal injury, death or substantial property
damage.
DO NOT adjust or attempt to measure gas valve outlet
pressure. The gas valve is factory-set for the correct outlet
pressure. This setting is suitable for natural gas and pro-
pane, requiring no field adjustment. Attempting to alter
or measure the gas valve outlet pressure could result in
damage to the valve, causing potential severe personal
injury, death or substantial property damage.
Ultra boilers are shipped ready to fire natural gas ONLY.
(Exception: Ultra-80LP is propane-ready.) You must
install the propane orifice if the boiler will be connected
to propane. See page 44. Failure to comply could result
in severe personal injury, death or substantial property
damage.
Gas pipe sizing
1. See page 77 for gas line sizing information.
Check gas pressure at inlet to boiler
1. See Figure 37, page 36, Figure 38, page 36, or Figure 39, page 37
for location of the gas inlet pressure test port.
Part number 550-100-090/0809
— Boiler Manual
Figure 31 to pipe gas to
Figure 31
Natural gas supply pressure
1.
2.
Propane supply pressure
1.
2.
Use two wrenches when tightening gas
piping at boiler, using one wrench to pre-
vent the boiler gas line connection from
turning. Failure to support the boiler gas
connection pipe to prevent it from turn-
ing could damage gas line components.
Connect gas supply piping
Pressure required at gas valve inlet pressure port:
a. Maximum: 13" w.c. with no flow (lockup) or with
boiler on
b. Minimum: 4" w.c. (for all except 5" for -299) with
gas flowing (verify during boiler startup, while boiler
is at high fire)
Install 100% lockup gas pressure regulator in supply line
if inlet pressure can exceed 13" w.c. at any time. Adjust
lockup regulator for 13" w.c. maximum.
Adjust propane supply regulator provided by gas sup-
plier for 13" w.c. maximum pressure.
Pressure required at gas valve inlet pressure port:
a. Maximum: 13" w.c. with no flow (lockup) or with
boiler on
• Minimum: 4" w.c. with gas flowing (verify during
boiler startup, while boiler is at high fire).
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