GIM1329-075
9
Model 122 Regulators Installation and Maintenance Instructions
Condensed Parts List 1½", 2", and 2½" Model 122
Note: For ILL. No's 1, 2, 3, 6, 11a, 11b, 12e, 13, 14a, 14b, 16a, 16b, 17a, 21a,
24a, 41 and 42. See Page 6 CONDENSED PARTS LIST.
(Continued)
Illustration
Number
Description
Part
Number
12t
Stem Stainless
121-42-016-03
13
O-ring ⅜" x ½"
934007
14
Wave Washer
905479
14a
Valve Washer Ret. (B/P)
121-16-103-50
14b
Valve Spacer Washer (B/P)
121-16-102-52
15
Valve, Buna-N
121-16-311-50
16a
Retaining Ring, (5100-75H)
904447
16b
Valve Holder
121-16-130-50
16b
Valve holder (Stainless Steel)
121-16-130-51
17a
Spring Holder
121-42-018-00
19
Orifice, 2
5
/
32
" dia., Std.
121-16-023-51
19
Orifice, 2
5
/
32
" dia., Stainless
121-16-023-52
26
Gasket
121-42-063-00
27
Valve Stem Bushing
121-42-373-00
32
Tetreseal (or O-ring), 3¼" x 3½"
904078
40
Control Tube
121-42-315-00
43
Control Tube
121-43-315-00
45
Travel Indicator
Repair Kit – consisting of Main and Seal
Diaphragms, Seal Washers, Molded Valve
with Wave Washer and Retaining Ring,
Tetraseals and Gaskets: All internal
control models except Back Pressure or
Relief (Std.)
Internal Control Back Pressure and Relief
All external control models (Std.)
091-00-365-65
121-42-598-00
121-42-598-02
121-42-598-01
Maximum Emergency Pressures
Be certain the following section is clearly understood before using
the information.
The maximum inlet pressure a Model 122 regulator may be
subjected to under abnormal conditions without causing internal
damage is 20 psi.
The Maximum pressure the diaphragm may be subjected to
under abnormal conditions without causing internal damage is
set-point plus 2 psi. Set-point is defined as the outlet pressure a
regulator is adjusted to deliver.
If either of the above limits is exceeded the regulator must be
taken out of service and inspected. Damaged or otherwise
unsatisfactory parts must be repaired or replaced before returning
the regulator to service.
The maximum pressure that can be safely contained by the
diaphragm case on a Model 122 regulator is 5 psi. Safely
contained means no leakage as well as no bursting.
Over-pressurization Protection
Protect the downstream piping system and the regulator’s low
pressure chambers against over-pressurization due to the
possible regulator malfunction or failure to achieve complete
lockup. The allowable outlet pressure is the lowest of the
maximum pressures permitted by federal codes, state codes,
Sensus Bulletin RDS-1498, or other applicable standards. The
method of protection can be a relief valve, monitor regulator,
shutoff device, or similar mechanism.
Full Open Capacity/
Capacities At Other Pressures
Capacity of the Model 122 in the wide-open position can be
calculated using the following formula and K factors:
1.
Q = K
√
P
0
(P
1
– P
0
)
Q = Full open capacity in SCFH of 0.6 specific gravity
natural gas.
P
0
=
absolute
inlet pressure (psia)
P
1
=
absolute
outlet pressure (psia)
2.
K Factors=
1" Model 122-8
K = 1400
1¼" Model 122-8
K = 1750
1½" Model 122-12
K = 2750
2" Model 122-12
K = 4750
2½" Model 122-12
K = 5250
Remember at the above full open capacities the droop is
significantly greater than specified in the capacity tables.
When checking 122 regulator capacity to provide adequate relief
valve capacity, use the above calculated full open capacity.
Capacities for pressure reductions not listed in the table can be
calculated with the above formula.
Dimensions
GIM1329-075
A
B
C
D
E
F
Shpg.
Wt.
1" NPT
10¼"
11⅝"
1⅞"
5¾"
2½"
3
7
⁄
16
"
15 lbs.
1¼" NPT
10¼"
11⅝"
1⅞"
5¾"
2½"
3
7
⁄
16
"
15 lbs.
1½" NPT
14"
13"
2⅜"
7½"
3
15
⁄
16
"
3
9
⁄
16
"
28 lbs.
2" NPT
14"
13"
2⅜"
7½"
3
15
⁄
16
"
3
9
⁄
16
"
28 lbs.
2½" NPT
14"
13"
2⅜"
8¼"
3
15
⁄
16
"
3
9
⁄
16
"
30 lbs.
Optional
Control Line
Connection
½" N.P.T.
A (Diameter)
B
C
D
E
F
Vent Outlet
¼" N.P.T.
*Taps must be
specified when
ordering.
