Sensus 121 Series - Page 8

8
Installation and Maintenance
Model 121 Regulators
Condensed Parts List 3/4", 1" and 1-1/4"
Illustration Description Part
Number Number
1 Seal Cap 143-16-005-00
1a Seal Cap 121-10-005-52
2
Tetraseal (or O-Ring)
905241
2-1/4" x 2-3/8"
2a Tetraseal (or O-Ring)
906534
1-1/2" x 1-5/8"
3 Adjustment Spring Button 143-16-009-00
3a Spring Adjusting Screw 906537
4 Jam Nut 1/2"-13 921005
5 Housing Cover 121-10-005-51
7a Top Spring Button 121-10-009-51
7b
Thrust Bearing, stainless ball,
930510
3/8" diameter
9 Spring, see table “Spring Ranges”
121-8 Standard Diaphragm
Assembly (3-1/2" w.c. to 4-1/4" 121-10-550-52
psi outlet pressure)
11a Elastic Stop Nut 52-NTE-066 908561
11b Bottom Spring Button 121-10-220-50
11 11c Diaphragm Pan 121-10-017-50
11d Diaphragm, Buna-N 121-10-150-50
11d Diaphragm, Viton 121-10-150-52
11f Seal Washer 121-10-178-50
11h Diaphragm Stud,
091-16-058-02
Stainless Steel
121-8 HP High Pressure Diaphragm
Assembly (3 psi to 10 psi 121-10-550-55
outlet pressure)
11a Elastic Stop Nut 29-NE-066 903955
11b Bottom Spring Button 121-10-022-53
11c Diaphragm Pan 121-10-017-50
11 11d Diaphragm, Buna-N 121-10-150-50
11d Diaphragm, Viton 121-10-150-52
11e Upper Plate 121-10-022-52
11f Seal Washer 121-10-178-50
11g Lower Plate 121-10-079-52
11h Diaphragm Stud,
091-16-058-02
Stainless Steel
121 Seal Diaph Assembly Buna-N 121-10-564-51
121 Seal Diaph Assembly Viton 121-10-564-52
12a Piston 121-10-053-51
12 12b Seal Diaphragm, Buna-N 121-10-364-50
12b Seal Diaphragm, Viton 121-10-364-51
12c Plate 121-10-010-50
12d Stem, Stainless Steel 121-10-016-53
13
O-Ring, Buna-N, 3/8" x 1/2" 934007
O-Ring,Viton, 3/8" x 1/2" 902418
14 Wave Washer 905479
15
Molded Valve, Buna-N (45-50 Duro) 121-10-311-50
Molded Valve, Viton-A (65-75 Duro) 121-10-311-51
Condensed Parts List 3/4", 1" and 1-1/4"
Illustration Description Part
Number Number
16a Retaining Ring 904447
16b
Valve Holder, split (pair required),
121-16-130-51
Stainless Steel
19
Orifice, 1-1/4" dia., brass 143-16-023-03
Orifice, 1-1/4" dia., stainless steel 143-16-023-14
26 Gasket 121-16-063-51
32 Tetraseal (or O-Ring) 2-3/8" x 2-1/2" 904081
Repair Kits, consisting of Buna-N
Main and Seal Diaphragms,
Buna-N Molded Valve plus Wave
46 Washer and Retaining Ring, Buna-N
O-Rings, Tetraseals and Gaskets:
For 121-8 121-10-598-50
For 121-8 HP 121-10-598-51
For Back Pressure Models
Item 12d above, Stem,
12 Stainless steel – substitute 121-10-016-55
Stem, Back Pressure
Item 14 above, Wave Washer – 121-16-102-52
14 substitute 121-16-103-51
Poly-U Disk Retainer 121-10-023-50
Item 19 above, Orifice – substitute
19
Orifice, Back Pressure (Brass)
121-10-023-51
Orifice, Back Pressure
(Stainless Steel)
Item 46 above, Repair Kits –
46
substitute
For 121-8 Back Pressure 121-10-598-54
For 121-8 HP Back Pressure Contact Sensus
Add Item 47
47 Valve, Seal Diaphragm and 121-10-511-54
Stem Assembly