Install Instructions

Figure 8 Install pipe fi ttings for relief valve and
pressure/temperature gauge —
DO
NOT mount relief valve until AFTER
hydrostatic testing
(see legend below)
Part number 550-100-191/0917
14
®
gas-fired water boiler — 70/110/155 Boiler Manual
1 Boiler supply (outlet) connection, (male, 1" NPT )
2 Boiler return (inlet) connection, (male, 1" NPT )
3 Boiler relief valve, shipped loose with boiler — DO NOT mount relief valve until AFTER hydrostatic testing.
3a TEMPORARILY ONLY — Insert a ¾" NPT plug in the relief valve tapping of the reducing tee. This MUST BE REMOVED after
the test and the relief valve mounted here.
4 Pressure/temperature gauge, shipped loose with boiler
5a Reducing tee, NPT, 1 " x 1 " x ¼" on 70/110, & 1 ¼" x 1 ¼" x ¼" on 155, shipped loose with boiler
5b Reducing tee, NPT, 1 " x 1 " x ¾" on 70/110, & 1 ¼" x 1 ¼" x ¾" on 155, shipped loose with boiler
6 Nipple, NPT 1" x close on 70/110, & 1 ¼" x close on 155, shipped loose with boiler
7 Bushing, NPT, 1 ¼" x 1", shipped loose with boiler (155 only)
8 Nipple, NPT 1" x close on 70/110, & 1 ¼" x close on 155, by installer
9 Isolation valve on supply connection, by installer (1" NPT on 70/110, 1¼" NPT on 155)
10 Isolation valve on return connection, by installer (1" NPT on 70/110, 1¼" NPT on 155)
11 ¾" NPT boiler drain valve, shipped loose with boiler — after hydrostatic testing, move drain valve to lowest point on the return piping if not
already there.
Boiler hydrostatic test (continued)
(9*
(
9
11
Piping from system
Piping to system
2
3
1
Figure 9 Install piping components required for
hydrostatic test (
see legend below)
Recommended but
not included
C

B

B



C
(9*D




(155 only)
(155 only)