Weil-McLain Evergreen EVG 110, Manual

Page: 53 / 144

Gas piping
Evergreen
®
boilers are shipped ready to operate
on natural gas ONLY. You must install the
propane orifi ce if the boiler will be connected
to propane. See page 15 . Failure to comply
could result in severe personal injury, death or
substantial property damage.
Connecting gas supply piping
1. Remove jacket door and refer to Figure 58 to pipe gas to boiler.
a. Place a pipe wrench on the gas line inside the jacket when
tightening the gas line assembly to the boiler gas connection
(item 1).
b. Install steel pipe fi ttings and factory-supplied manual gas
shut off valve as shown in Figure 58 . All pipe fi ttings are
supplied by the installer. The manual gas shut off valve is
shipped loose with the boiler.
c. In Canada — The manual gas shut off valve (item 2) must
be identifi ed by the installer.
2. Use pipe dope compatible with propane gases. Apply sparingly
only to male threads of pipe joints so that pipe dope does not
block gas fl ow.
Failure to apply pipe dope as detailed above can result
in severe personal injury, death or substantial property
damage.
3. Connect gas supply piping to the ½" NPT manual gas shut off
valve (item 2).
4. Support gas piping with hangers, not by boiler or its accessories.
5. Purge all air from gas supply piping.
6. Before placing boiler in operation, check boiler and its gas
connection for leaks.
a. During any pressure testing at less than 13" (330 mm) w.c.,
close the gas shutoff valve and disconnect system gas piping.
At higher test pressures, disconnect boiler and gas valve from
gas supply piping.
Do not check for gas leaks with an open fl ame — use
bubble test. Failure to use bubble test or check for
gas leaks can cause 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 propane. 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.
Gas pipe sizing
1. See page 21 for gas line sizing information.
Check gas pressure at inlet to boiler
1. See Figure 83, page 96 ( EVG 70), Figure 84, page 97 ( EVG 110)
or Figure 85, page 98 ( EVG 155) for location of the gas inlet
pressure test port.
Figure 58 Connect gas supply piping
2. For natural gas or propane, the pressure required at gas
valve inlet pressure port (verify minimum gas pressure
when all gas appliances are in operation):
a. Maximum: 13" (330 mm) w.c. with no fl ow (lockup)
or with boiler on.
b. Minimum gas pressure, with gas fl owing (verify
during boiler startup, while boiler is at high fi re) :
EVG 70: 3½" (89 mm) w.c.;
EVG 110: 3½" (89 mm) w.c.;
EVG 155: 3½" (89 mm) w.c.
c. Nominal gas pressure: 11.0" (279 mm) w.c.
3. Install 100% lockup gas pressure regulator in supply
line if inlet pressure can exceed 13" (330 mm) w.c. at
any time. Adjust lockup regulator for 13" (330 mm)
w.c. maximum.
Part number 550-100-191/0917
53
®
g
as-fired water boiler —
70/110/155
Boiler Manual
1 Boiler gas supply connection, ½" NPT male
2 Manual gas shut off valve, ½" NPT, shipped loose with boiler
ALL OF THE FOLLOWING ARE SUPPLIED BY THE INSTALLER:
3 Nipple, ½" NPT
4 Union, ½" NPT
5 Nipple, ½" NPT
6 Tee, ½" NPT
7 Nipple, ½" NPT x 4", for drip leg
8 Cap, ½" NPT
Use two wrenches when tightening gas
piping at boiler, using one wrench to
prevent the boiler gas line connection
from turning. Failure to support the
boiler gas connection pipe to prevent
it from turning could damage gas line
components.