Propane Gas - Weil-McLain Ultra Commercial Installation And Start-Up Manual

COMMERCIAL GAS
Gas piping
Natural gas supply pressure
1. Pressure required at gas pressure tap near boiler gas
connection (see Figure 51, page 49):
a. Maximum: 14" w.c. with no flow (lockup) or
with boiler on.
b. Minimum: 3.5" w.c. with gas flowing (verify
during boiler startup, while boiler is at high
fire).
c. If no external pressure tap is available, con-
nect manometer to the gas pressure switch tee
(Figure 52). At this point, the minimum gas
pressure required is 3.0" w.c.

Propane Gas:

You must follow the instructions in this
manual, beginning on page 9, to operate
the boiler on propane. Failure to comply
could result in severe personal injury,
death or substantial property damage.
Pipe sizing for propane gas
1. Contact gas supplier to size pipes, tanks and 100%
lockup gas pressure regulator.
Propane supply pressure
1. Pressure required at gas pressure tap near boiler gas
connection (see Figure 51, page 49):
a. Maximum: 14" w.c. with no flow (lockup) or
with boiler on.
b. Minimum: 3.5" w.c. with gas flowing (verify
during boiler startup, while boiler is at high
fire).
c. If no external pressure tap is available, connect
manometer to the gas pressure switch tee (Fig-
ure 52, page 49). At this point, the minimum
gas pressure required is 3.0" w.c.
Manifolded gas supply lines
1. Construct gas header for multiple boilers using
Figure 53 and the sizing tables below. Refer to the
National Fuel Gas Code for other conditions.
2. Provide manual shutoff gas valve, union and
sediment trap (minimum 3 inches below tee) as
shown in Figure 51, page 49 and Figure 53 for
each boiler.
3. A 1¼" NPT gas piping riser from header to boiler
will be large enough for most jobs. Ensure the pip-
ing is large enough so that the minimum pressure
at the boiler, with all connected appliances firing,
will be as specified on page 50 (natural gas) or
page 50 (propane).
Gas pressure switches
1. Ultra Commercial boilers are equipped with
manual reset high gas pressure and low gas pressure
switches (see items 31 and 32, page 3).
50
-
FIRED WATER BOILER
(continued)
— Boiler Manual
Common gas line for multiple boilers
Pipe capacity for natural gas
10 1050
20 730
30
40 500
50 440
75 360
100 305
150 250
Equivalent lengths of straight pipe for gas line fittings
inches
1¼
1½
2
2½
2. These switches are factory set and should remain at the following
settings:
a. High gas pressure: 14 inches w.c.
b. Low gas pressure: 2 inches w.c.
3. Note that the low gas pressure switch must be manually reset (button
on front of switch) on initial start-up or any time the gas supply is
turned off.
1600 3050
1100 2100
1650
760 1450
670 1270
545 1020
460 870
380 710
3.45
4.02 8.04
5.17 10.3
6.16 12.3
Part number 550-100-086/0809
4800
3300
2700
2300
2000
1650
1400
1130