800.323.0688

Series 120 Safety Valves





120 Cut View
Series 120
125 Cut View
Series 125





121 Cut View
Series 121
126 Cut View
Series 126




Series 120 thru 126
Item Description Brass Option Stainless Option
1 Body B16 316 Stainless
2 Disc Bronze 316 Stainless
3 Seal Wire Steel/Lead Steel/Lead
4 Lock Screw B16 B16
5 Bonnet Bronze Bronze
6 Support Stainless Stainless
7 Spring Plate Brass Brass
8 Lift Lever Plated Steel Plated Steel
9 Spring Stainless Stainless
10 Spring Post B16 B16
11 Lift Pin B16 B16
12 Nameplate Stainless Stainless
13 Hood Bronze Bronze
14 Lever Pin B16 B16
15 Hood Mount B16 B16







Series 120 thru 126
Series Inlet Outlet Seat Dimensions Inches – (mm) Max. Set
PSI – (Barg)
Weight
Lbs – (Kg)
A B C
120 1/2” Top 3/4” 3­˗1/2" (89) -
1­˗1/2" (38) 200 (13.8) 1/2 (.2)
120 3/4” Top 3/4” 3­˗1/2" (89) -
1­˗1/2" (38) 200 (13.8) 5/8 (.3)
120 1” Top 3/4” 3­˗1/2" (89) -
1­˗1/2" (38) 200 (13.8) 5/8 (.3)
120* 1” Top 1” 3­˗3/4" (95) -
1­˗1/2" (38) 200 (13.8) 1 1/8 (.5)
121 1/2” Top 3/4” 4­˗1/8" (105) -
1­˗3/8" (35) 200 (13.8) 3/4 (.3)
121 3/4” Top 3/4” 4­˗1/8" (105) -
1­˗3/8" (35) 200 (13.8) 7/8 (.4)
121 1” Top 3/4” 4­˗1/8" (105) -
1­˗3/8" (35) 200 (13.8) 7/8 (.4)
121* 1” Top 1” 4­˗1/2" (114) -
1­˗3/8" (35) 200 (13.8) 1 (.6)
125 1/2” 3/4” 3/4” 3­˗1/2" (89) 2­˗1/4" (57) 1­˗1/8" (29) 200 (13.8) 1/2 (.2)
125 3/4” 3/4” 3/4” 3­˗1/2" (89) 2­˗1/4" (57) 1­˗1/8" (29) 200 (13.8) 5/8 (.3)
125 1” 3/4” 3/4” 3­˗1/2" (89) 2­˗1/4" (57) 1­˗1/8" (29) 200 (13.8) 5/8 (.3)
125* 1” 1” 1” 3­˗3/4" (95) 2­˗5/8" (67) 1­˗3/8" (35) 200 (13.8) 1 1/8 (.5)
126 1/2” 3/4” 3/4” 4­˗1/8" (105) 2­˗1/4" (57) 1­˗1/8" (29) 200 (13.8) 1/2 (.2)
126 3/4” 3/4” 3/4” 4­˗1/8" (105) 2­˗1/4" (57) 1­˗1/8" (29) 200 (13.8) 5/8 (.3)
126 1” 3/4” 3/4” 4­˗1/8" (105) 2­˗1/4" (57) 1­˗1/8" (29) 200 (13.8) 5/8 (.3)
126* 1” 1” 1” 4­˗1/2" (114) 2­˗5/8" (67) 1­˗3/8" (35) 200 (13.8) 1 1/8 (.5)
* 1” seat is non-code














ORDERING


Series 120 thru 126 Part Numbers
121 B A 1 M 1 K 1 125
Series/Description Inlet/Outlet Metals Connection Seating Cap Service Options Set
120 Top Outlet
w/Lift Lever
A- 1/2" A- Brass
Bronze
1- NPT MxF M- Metal 1- Lift lever K- ASME VIII
Air/gas
1- None Ex.125
B- 3/4" 2- NPT FxF

H- Hood and
Lift Lever
2- Chrome
Plating

121 Top Outlet Hood
And Lift Lever
C- 1" B- 316 SS
Bronze
3- BSPT MxF

L- ASME VIII
Steam

*D- 1" x 1" 4- BSPT FxF



3- O2
Cleaned





L- No Lead
Bronze
8- BSPP MxF



N- Non-code
Air/gas

125 Side Outlet
w/Lift Lever
A- 1/2" x 3/4" 9- BSPP FxF






B- 3/4" x 3/4" M- 316 SS
No Lead






T- Non-code
Steam



126 Side Outlet Hood
And Lift Lever
C- 1" x 3/4"








*D- 1" x 1"













Valves with Inlet/Outlet 'D' are Non-Code






CAPACITIES

AIR

Series 120 thru 126
Air Capacity SCFM @ 10%
Over Set Pressure

Series 120 thru 126
Air Capacity Nm3/hr @ 10%
Over Set Pressure
Slope 1.037 1.192
Slope 1.037 1.192
PSI 3/4” Seat 1” Seat*
Bar 3/4” Seat 1” Seat*
5 24 27
0.2 36 42
10 29 33
0.5 44 51
15 34 39
1 57 65
20 39 45
2 82 95
25 44 51
3 110 127
40 61 70
4 138 159
50 72 84
5 166 191
75 101 117
6 194 224
100 129 150
7 223 256
125 158 183
8 251 288
150 186 216
10 307 353
175 215 249
12 363 417
200 243 282
14 419 482

STEAM
Series 120 thru 126
Steam Capacity #/Hr @ 10%
Over Set Pressure

Series 120 thru 126
Steam Capacity kg/hr @ 10%
Over Set Pressure
Slope 2.91 3.358
Slope 2.91 3.358
PSI 3/4” Seat 1” Seat*
Bar 3/4” Seat 1” Seat*
5 66 85
0.2 27 31
10 81 104
0.5 33 38
15 95 123
1 43 49
20 110 141
2 62 71
25 124 160
3 83 95
40 171 220
4 104 120
50 203 261
5 125 144
75 283 364
6 146 168
100 363 468
7 167 192
125 443 571
8 188 217
150 523 674
10 230 265
175 603 777
12 272 314
200 683 880
14 314 363







* 1” Seat is Non-Code



Set pressures below 15 PSI (1.03 Bar) are NON-Code.
Maximum back-pressure is 10% of set pressure or 50 PSI (3.45 Bar) whichever is less.
Lifting Device as required by the ASME, ASME Section VIII: UG136(3)
Each pressure relief valve on air, water at the valve inlet that exceeds 140°F (60°C), excluding over-pressure or relief events, or steam service
shall have a substantial lifting device which when activated will release the seating force on the disc when the pressure relief valve is
subjected to a pressure of at least 75% of the set pressure of the valve.

* 1" Seat is Non-Code