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12d
14
13
15
12f
19
12d
14
19
12e
15
Installation and Maintenance
Model 121 Regulators
2
1
3
9
45
21
22
23
24
25
26
27
29a
29
30
33
34
35
32
37
38
19a 19
13
14
15
d
c
b
a
12
13
h
f
d
c
b
a
11
21a
18
16b
16a
1" NPT Vent
connection
1/4" NPT Vent
connection
e
21
45
22
23
24
27
1
a
c
d
f
11
9
3
2
21a
25
26
29a
29
h
b
1" NPT Vent
connection
1/4" NPT Control
line connection
4
3a
5
7a
7b
9
21
45
21
22
23
24
25
26
29
1a
2a
2
29a
21a
a
b
c
e
d
f
g
h
11
High Pressure
Spring Adjustment
27
1" NPT Vent
connection
1/4" NPT
Control
line
connection
121-12 – Standard
121-8 – Standard
V-Port Wing Option
Standard Retainer Option
121-8 HP – High Pressure
1-1/2" – 2" – 2-1/2"
Standard, Differential, Atmospheric or Zero Governors
11
2
1
3
9
29a
Fig. 1
Adjustment 3 and Vent Connection
21b for Differential Regulators,
Atmospheric Regulators and
Zero Governors
Pipe Sizes
(inlet x outlet) Screwed, NPT
1-1/2" x 1-1/2"
1-1/2" x 2"
2" x 2"
2-1/2" x 2-1/2"
Flanged ANSI 125 lb. FF
2" x 2"