5
L
K
f.
Reinstall gauge glass and trim to ‘Y’ fittings (K, L).
Note:
Make sure gauge glass valves are fully open.
L
K
d.
• Install upper ‘Y’ fitting (K) into upper 1/2” NPT
gauge glass tapping on boiler.
• Install lower ‘Y’ fitting (L) into 1/2” NPT gauge
glass tapping on boiler.
S
R
P
Q
M
BB
Z
W
T
Y
AA
V
U
X
N
O
e.
• Screw reducer bushing (O) and nipple (N) into top 1” NPT
tapping (P).
• Screw reducer bushing (Q), nipple (R) and blow-off
valve (S) into bottom 1” NPT tapping (T).
• Screw lower union tailpiece (V) with nut (U) into either
1/2” NPT lower tapping (W, X). Screw 1/2” NPT pipe
plug into unused lower tapping.
• Screw upper union tailpiece (Z) with nut (Y) into ‘Y’
casting (M) 1/2” NPT tapping (AA).
• Slide ‘Y’ casting (M) and compression nut (BB) over
nipple (N).
• Connect upper and lower union nuts (U, Y) to ‘Y’ fittings
(K, L) installed in boiler gauge glass tappings.
Note:
‘Y’ fitting (M) will have to be moved up or down
nipple (N) to mate union halves.
• Tighten compression nut (BB).
Summary of Contents for McDonnell & Miller 42S-N Series
Page 1: ...INSTRUCTION MANUAL MM 231G...
