Sensus 121 Series Installation And Maintenance Instructions Manual Download Page 13

13

Installation and Maintenance

Model 121 Regulators

Condensed Parts List 1-1/2", 2" and 2-1/2"

Illustration

Description

Part

Number

Number

1

Seal Cap

143-16-005-00

1a

Seal Cap

121-10-005-52

2

Tetraseal (or O-Ring) 2-1/4" x 2-3/8" 905241

2a

Tetraseal (or O-Ring) 1-1/2" x 1-5/8" 906534

3

Adjustment Spring Button

143-16-009-00

3a

Spring Adjusting Screw

906537

4

Hex Steel Nut

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”
121-12 Diaphragm Assembly 

121-16-550-51

(3-1/2" w.c. to 2 psi outlet pressure)
11a Elastic Stop Nut 52-NTE-066

908561

11b Bottom Spring Button

121-10-022-50

11

11c Diaphragm Pan

121-16-017-50

11d Molded Diaphragm, Buna-N

121-16-150-53

11d Diaphragm, Viton

121-16-150-55

11f Seal Washer

121-10-178-50

11h Diaphragm Stud, stainless steel 121-16-058-52
121-8 Standard Diaphragm 
Assembly

121-10-551-52

(1 psi to 4-1/4 psi outlet pressure)
11a Elastic Stop Nut 29-NE-066

903955

11

11b Bottom Spring Button

121-10-022-50

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, stainless steel 091-16-058-02
121-8 HP High Pressure 
Diaphragm Assembly

121-10-550-55 

(3 psi to 10 psi outlet pressure)
11a Elastic Stop Nut 29-NE-066

903955

11b Diaphragm Plate

121-10-022-53

11

11c Diaphragm Pan

121-10-017-50

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, stainless steel 091-16-058-02
121 Seal Diaph Assembly, Buna-N

121-16-564-51

121 Seal Diaph Assembly, Viton

121-16-564-52

12a Piston

121-16-053-51

12b Seal Diaphragm, Buna-N

121-16-364-50

12

12b Seal Diaphragm, Viton

121-16-364-51

12c Plate

121-16-010-53

12d Stem, stainless steel

121-16-016-53

12e Retainer

121-16-016-00

12f  V-Port Wings

121-16-012-52

O-Ring, Buna-N 3/8" x 1/2"

934007

13

O-Ring, Viton 3/8" x 1/2"

902418

14

Wave Washer

905479

Condensed Parts List 1-1/2", 2" and 2-1/2"

Illustration

Description

Part

Number

Number

15 

Molded Valve, Buna-N (45-50 Duro) 121-16-311-50
Molded Valve, Viton-A (65-75 Duro) 121-16-311-51

16a

Retaining Ring

904447

16b

Valve Holder, split (pair required) 

121-16-130-51

stainless steel

18

Tetraseal (or O-Ring)

904207

2-1/2" x 2-11/16"

19

Orifice, 2-5/32" dia., stainless steel

121-16-023-51

Orifice, 2-5/32" dia., stainless steel

121-16-023-52

19a

Retaining Ring, stainless

904656

26

Gasket

121-16-063-51

29a

Copper Washer

121-16-178-51

30

O-Ring, 3-1/8" x 3-1/2"

934041

32

Tetraseal (or O-Ring) 3-1/4" x 3-1/2" 904078

33

Seal Diaphragm Ring

121-16-008-50

34

Gasket

121-16-104-50

45

Travel Indicator

Contact Sensus

Repair Kits, consisting of Buna-N Main and Seal 
Diaphragms, Buna-N Molded Valve plus Wave 
Washer and Retaining Ring, Buna-N O-Rings, 

46

Tetraseals and Gaskets:
For 121-12

121-16-598-50

For 121-8

121-86-598-50

For 121-8 HP

121-86-598-51

For Back Pressure Models

Item 12d above, Stem,

12

Stainless Steel – 

121-16-016-55

substitute Stem, Back Pressure
Item 14 above, 

14

Wave Washer – substitute
Poly-U Disk

121-16-102-52

Retainer

121-16-103-51

Item 46 above, 
Repair Kits – substitute

46

For 121-12 Back Pressure

121-16-598-52

For 121-8 Back Pressure

121-86-598-54

For 121-8 HP Back Pressure

121-86-598-55

Add item 47

47

Valve, Seal Diaphragm and 

121-16-511-51

Stem Assembly

Summary of Contents for 121 Series

Page 1: ...RM 1328 R10 Sensus Metering Systems Model 121 Regulators T H E G A S I N D U S T R Y Installation and Maintenance Instructions ...

Page 2: ...ust be strong 1 4 for 121 8 and 121 12 1 2 for 121 16 or larger steel tubing or pipe is preferred It must be well protected against breakage Regulator will open wide if the control line breaks 9 Make sure the regulator is correctly connected and adequately supported Ensure all pipe joints are tight Start Up A The inlet and outlet shutoff valves should both be closed If a by pass is used the by pas...

Page 3: ...cing adjustment button 3 or 3a 4 Adjust for the desired outlet pressure per previous section Set Point Adjustment 5 When adjustment is complete replace top cap 1 Screw it securely into place Failing to replace cap could result in unstable regulator operation 6 New spring range should be marked on regulator If old spring range appears on regulator it should be removed CAUTION The diaphragm case ven...

Page 4: ...121 8HP 6 psi to 10 psi Cadmium 143 16 021 08 outer 60 psi 8 White 143 16 021 13 inner 1 1 2 to 3 1 2 w c Red 143 16 021 03 main spring _ 120 10 021 10 counterspring 1 1 2 to 12 w c Maroon 121 42 021 00 main spring _ 120 10 021 10 counterspring 1 1 2 2 and 2 1 2 3 1 2 to 6 1 2 w c Red 2 O D 143 16 021 03 60 psi 12 Model 121 12 5 to 8 1 2 w c Blue 2 O D 143 16 021 04 6 to 14 w c Green 2 O D 143 16 ...

Page 5: ...psi to 3 psi Cadmium 143 16 021 08 40 psi 3 121 3 4 x 3 4 not available Back Pressure Regulator or Relief Valve Relief or Back Maximum Diaphragm Size Pressure Range Spring Color Part Number Case Pressure 3 to 5 1 2 w c Red Black 143 82 021 00 5 to 7 1 2 w c Blue Black 143 82 021 01 3 4 thru 2 1 2 6 to 13 w c Green Black 143 82 021 02 121 8 10 to 15 w c Blue 2 O D 143 16 021 04 10 psi 12 to 25 w c ...

Page 6: ...d c 2a 2 21a 1 4 NPT Control line connection 1 NPT Vent connection 6 3 4 1 1 1 4 Standard Differential Atmospheric or Zero Governors 16b 15 14 13 12 a b 11 a c h 3 1 35 22 23 21 24 25 26 27 29 37 38 32 19 16a c d f d 1 4 NPT Control line connection b 13 21a 2 45 1 NPT Vent connection 9 121 8 Standard 121 8 HP High Pressure Pipe Sizes inlet x outlet Screwed NPT 3 4 x 1 3 4 x 1 1 4 1 x 1 1 x 1 1 4 1...

Page 7: ...on 1 NPT Control line connection 7 h 11 13 1a 3a High Pressure Spring Adjustment 4 2a 2 21a a b c d e f g 27 25 26 24 23 22 21 45 21 9 7b 7a 5 1 NPT Vent connection 1 4 NPT Control line connection 121 8 High Pressure Back Pressure 3 4 1 1 1 4 Back Pressure Installation and Maintenance Model 121 Regulators 121 8 Back Pressure ...

Page 8: ...al 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 ...

Page 9: ...Carefully note location and position of all parts to be certain of correct reassembly Abrasive side of emery cloth washers face against diaphragm To reassemble replace parts in reverse sequence Make sure the screwed connection between 11h and 12d is loose by approximately 1 2 turn To do this carefully rotate diaphragm assembly 11 clockwise until this screwed connection bottoms do not jam it togeth...

Page 10: ...tion and position of all parts to be certain of correct reassembly Abrasive side of emery cloth washers face against diaphragm To reassemble replace parts in reverse sequence Make sure the screwed connection between 11h and 12d is loose by approximately 1 2 turn To do this carefully rotate diaphragm assembly 11 clockwise until this screwed connection bottoms do not jam it together Then back off di...

Page 11: ...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 Differen...

Page 12: ... g 11 h 25 26 27 29a 29 3a 4 5 7a 7b 9 21 45 21 22 23 24 High Pressure Spring Adjustment 1 NPT Vent connection 1 4 NPT Control line connection 121 12 Back Pressure 121 8 HP High Pressure Back Pressure 121 8 Back Pressure Installation and Maintenance Model 121 Regulators 1 1 2 2 2 1 2 Standard Differential Atmospheric or Zero Governors 12 Pipe Sizes inlet x outlet Screwed NPT 1 1 2 x 1 1 2 1 1 2 x ...

Page 13: ...gm Stud stainless steel 091 16 058 02 121 Seal Diaph Assembly Buna N 121 16 564 51 121 Seal Diaph Assembly Viton 121 16 564 52 12a Piston 121 16 053 51 12b Seal Diaphragm Buna N 121 16 364 50 12 12b Seal Diaphragm Viton 121 16 364 51 12c Plate 121 16 010 53 12d Stem stainless steel 121 16 016 53 12e Retainer 121 16 016 00 12f V Port Wings 121 16 012 52 O Ring Buna N 3 8 x 1 2 934007 13 O Ring Vito...

Page 14: ...and position of all parts to be certain of correct reassembly Abrasive side of emery cloth washers face against diaphragm To reassemble replace parts in reverse sequence Make sure the screwed connection between 11h and 12d is loose by approximately 1 2 turn To do this carefully rotate diaphragm assembly 11 clockwise until this screwed connection bottoms do not jam it together Then back off diaphra...

Page 15: ...f diaphragm assembly 11 counterclockwise approximately 1 2 turn The 11h to 12d screwed connection must not be tight To Service Seal Diaphragm 12b 1 Remove main diaphragm assembly 11 per steps 1 through 4 To Service Main Diaphragm 11d 2 Remove bolts 29 and centerpiece 27 then remove seal diaphragm valve and stem assembly 12 3 To disassemble 12 unscrew piston 12a from stem 12d Use a spanner wrench i...

Page 16: ...3 16 thick 2 1 3 9 45 21 22 23 24 25 26 27 28 13 a b c d f h 11 21a 1 4 NPT Control line connection 2 1 3 26 5 4 21a h f d c b a 11 13 a b c d 12 14 15a 15 16a 16b 17 18 19 19a 38 37 32 35 21 45 22 23 24 25 26 27 28 29 32 33 34 2a 8 7 9 10 1 4 NPT Control line connection 2a 1 3 9 45 21 a b c d f h 11 21a 22 23 24 28 27 26 25 1 NPT Vent connection 1 4 NPT Control line connection 3 4 Standard 3 4 Ba...

Page 17: ...sher substitute Poly U Disk 121 22 102 52 Retainer 121 22 103 50 17 Condensed Parts List 3 and 4 Illustration Description Part Number Number 3 Model 121 only 12a Piston 121 20 053 50 12b Seal Diaphragm Buna N 121 20 364 50 12 12b Seal Diaphragm Viton 121 20 364 51 12c Plate 121 20 010 50 12d Stem stainless steel 121 20 016 51 15 Molded Valve Buna N 45 50 Duro 121 20 311 50 Molded Valve Viton A 65 ...

Page 18: ...hat fabric side of seal diaphragm 12b faces upward and rubber side faces downward toward body Do not pinch loop in seal diaphragm 12b between ring 33 and centerpiece 27 Also rounded edge of 33 faces upward toward seal diaphragm 12b Make sure the screwed connection 11h and 12d is loose by approximately 1 2 turn To do this carefully rotate seal diaphragm assembly 12 clockwise until this screwed conn...

Page 19: ...uum The breaker inlet connects to a lesser vacuum to atmosphere or to a positive pressure The maximums for the positive pressure are 60 psi for 3 4 through 2 1 2 sizes 40 psi for 3 and 15 psi for 4 The vacuum breaker is normally closed and excess vacuum creates a valve opening movement which increases flow from the inlet and thereby relieves or breaks the excess All of the pipe sizes listed on Pag...

Page 20: ... 1 4 5 to 8 1 2 Blue Black 143 82 021 01 121 8 8 to 14 Green Black 143 82 021 02 12 to 20 Blue 143 16 021 04 18 to 30 Green 143 16 021 05 1 1 2 2 and 2 1 2 3 to 6 1 2 Red 143 16 021 03 121 12 5 to 8 1 2 Blue 143 16 021 04 8 to 14 Green 143 16 021 05 1 3 5 9 4 2 Vacuum Regulator Vacuum Regulators are used to maintain a certain negative pressure vacuum in enclosed spaces such as tanks vessels chambe...

Page 21: ...UTION There should be gas flow through the regulator during adjustment preferably small approximately 250 SCFH Do not adjust set point when there is no flow 3 When the desired set point is achieved retighten lock nut 12 and install seal cap 10 Make sure tetraseal 13 is not damaged Pilot Spring Change The outlet pressure range of the 121 RPC is determined by the pilot spring see table of Outlet Pre...

Page 22: ... service The maximum pressures that can be safely contained by model 121 diaphragm cases are as follows Model 121 8 25 psi Model 121 8HP 25 psi Model 121 12 20 psi Model 121 16 10 psi Safely contained means no leakage as well as no bursting Before using any of the above data make sure this entire section is clearly understood 22 Model 121 Regulators 121 PL Pressure Loaded The 121 PL is a pressure ...

Page 23: ... Model 121 Cast Iron Retaining Ring Plated Steel 1 1 2 thru 4 Model 121 Valve Plated Steel with Molded Buna N Soft Seal Valve Wing Plated Steel 3 Model 121 Valve Holder Plated Steel Retaining Ring and Wave Washer Stainless Steel O Rings and Tetraseals Buna N Adjustment Spring Ferrule Zinc Die Casting Bottom Spring Button Powdered Iron Plated Adjustment Screw 16 Diaphragm and H P Adjustment Spring ...

Page 24: ...30 days after Buyer discovers or should have reasonably discovered such purported defect or nonconformance and D shall only extend to Buyer and not to any subsequent buyers or users of the Goods Buyer shall provide Seller access to the Goods as to which Buyer claims a purported defect or nonconformance upon request by Seller Buyer shall at its own risk and expense promptly return the Goods in ques...

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