Sensus 121 Series - Page 5

Installation and Maintenance
Model 121 Regulators
5
Differential Regulator
Maximum Maximum Maximum
Differential Spring Body Diaphragm Pressure Diaphragm Case
Size Pressure Range Spring Color Part Number Pressure Differential Pressure
3-1/2" to 6-1/2" w.c. Red-Black 143-82-021-00
3/4", 1" and 1-1/4"
5" to 8-1/2" w.c. Blue-Black 143-82-021-01
121-8*
6" to 14" w.c. Green-Black 143-82-021-02 60 psi 2 psi 35 psi
12" to 28" w.c. Green 143-16-021-05
1 psi to 2 psi Orange (2" O.D.) 143-16-021-06
3-1/2" to 6-1/2" w.c. Red (2" O.D.) 143-16-021-03
1-1/2", 2" and 2-1/2"
5" to 8-1/2" w.c. Blue (2" O.D.) 143-16-021-04
121-12
6" to 14" w.c. Green (2" O.D.) 143-16-021-05 60 psi 2 psi 20 psi
12" to 28" w.c. Orange (2" O.D.) 143-16-021-06
1 psi to 2 psi Black 143-16-021-07
3-1/2" to 6-1/2" w.c. Red (3" O.D.) 121-62-021-50
3" and 4" 5" to 8-1/2" w.c. Blue (3" O.D.) 121-62-021-51 15 psi (4" 121)
1 psi 10 psi
121-16 6" to 14" w.c. Green (3" O.D.) 121-62-021-52 40 psi (3" 121)
12" to 28" w.c. Orange (3" O.D.) 121-62-021-53
3" and 4" 1 psi to 2 psi Black 143-16-021-07 15 psi (4" 121)
2 psi 20 psi
121-12 1-1/2 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. Green (2" O.D.) 143-16-021-05
18" w.c. to 2 psi Orange (2" O.D.) 143-16-021-06
1 psi to 4 psi Black 143-16-021-07
3/4" thru 2-1/2"
3 psi to 6 psi Cadmium** 143-16-021-08
121-8** 6 psi to 10 psi
Cadmium (outer)** 143-16-021-08 20 psi
White (inner) 143-16-021-13
3" to 5-1/2" w.c. Red (2" O.D.) 143-16-021-03
1-1/2", 2" and 2-1/2" 5" to 7" w.c. Blue (2" O.D.) 143-16-021-04
121-12 6" to 12" w.c. Green (2" O.D.) 143-16-021-05
10 psi
12" to 25" w.c. Orange (2" O.D.) 143-16-021-06
1-1/2" thru 4" 20" w.c. to 1-3/4 psi Black 143-16-021-07
121-12 1-1/2" to 2-3/4" psi Cadmium 143-16-021-08
3" to 4-1/2" w.c. Red (3" O.D.) 121-62-021-50
3" and 4"
3" to 6" w.c. Blue (3" O.D.) 121-62-021-51
121-16
5" to 11" w.c. Green (3" O.D.) 121-62-021-52 5 psi
10" to 24" w.c. Orange (3" O.D.) 121-62-021-53
14" w.c. to 1-1/4 psi Yellow 121-62-021-56
**Require High Pressure Spring Adjustment (121-8HP). *3/4" x 3/4" not available.