Safety Relief Valves
Relief Valve - 800
This low capacity relief valve has been designed for use in small pressure vessels. The ASME certified slope of 0.42 yields, for example, a capacity of 9.3 lbs per minute of air @ 250# set pressure. Increased Durability Corrosion Resistance
Product Spec Spotlight
- Set Pressure
- 50-400 psi
- Temp Range
- -20°F to 275°F
- Body Material
- Black Oxide Coated Carbon Steel
- Weight
- 3.2 lbs
Custom set pressures available at no additional charge — call us if you need a value outside this range.
ASME Certified
UV & NB stamped
100% Tested
Every valve, every time
American Made
Manufactured since 1912
Specifications & Details
Additional Specifications
1/2" MPT
- Outlet
- 3/4" FPT
- Configuration
- Dual Port, Open Port
- MAWP
- 500 psi
| Inlet | Outlet | Configuration | MAWP |
|---|---|---|---|
| 1/2" MPT | 3/4" FPT | Dual Port, Open Port | 500 psi |
Design Features
National Board Certification #: 51163 Set Pressure Range: 50-400 PSI in 25 PSI increments. Special Settings can be made at no extra charge and typically takes 1-2 extra days; Each valve undergoes 3 separate test sequences for set pressures and seals, and then are lock-wired for security.
| Design Features |
|---|
| National Board Certification #: 51163 Set Pressure Range: 50-400 PSI in 25 PSI increments. Special Settings can be made at no extra charge and typically takes 1-2 extra days; Each valve undergoes 3 separate test sequences for set pressures and seals, and then are lock-wired for security. |
800 Series Capacity Chart Slope = 0.42 SCFM/PSIA Standard Conditions [60 ˚ F, 1 Atm]
50
- Air SCFM
- 29.3
- Air lb/min
- 2.2
- Air lb/hr
- 134.0
- NH3 lb/min
- 1.7
- NH3 lb/hr
- 102.8
- R-22 lb/min
- 3.9
- R-22 lb/hr
- 231.5
- R-290 lb/min
- 2.8
- R-290 lb/hr
- 165.3
- R-404A lb/min
- 4.1
- R-404A lb/hr
- 246.0
- R-502 lb/min
- 1.4
- R-502 lb/hr
- 84.9
75
- Air SCFM
- 40.8
- Air lb/min
- 3.1
- Air lb/hr
- 186.9
- NH3 lb/min
- 2.4
- NH3 lb/hr
- 143.4
- R-22 lb/min
- 5.4
- R-22 lb/hr
- 322.9
- R-290 lb/min
- 3.8
- R-290 lb/hr
- 230.6
- R-404A lb/min
- 5.7
- R-404A lb/hr
- 343.0
- R-502 lb/min
- 2.0
- R-502 lb/hr
- 118.4
100
- Air SCFM
- 52.4
- Air lb/min
- 4.0
- Air lb/hr
- 239.8
- NH3 lb/min
- 3.1
- NH3 lb/hr
- 183.9
- R-22 lb/min
- 6.9
- R-22 lb/hr
- 414.3
- R-290 lb/min
- 4.9
- R-290 lb/hr
- 295.8
- R-404A lb/min
- 7.3
- R-404A lb/hr
- 440.1
- R-502 lb/min
- 2.5
- R-502 lb/hr
- 151.9
125
- Air SCFM
- 63.9
- Air lb/min
- 4.9
- Air lb/hr
- 292.6
- NH3 lb/min
- 3.7
- NH3 lb/hr
- 224.3
- R-22 lb/min
- 8.4
- R-22 lb/hr
- 505.6
- R-290 lb/min
- 6.0
- R-290 lb/hr
- 361.0
- R-404A lb/min
- 9.0
- R-404A lb/hr
- 537.1
- R-502 lb/min
- 3.1
- R-502 lb/hr
- 185.4
150
- Air SCFM
- 75.5
- Air lb/min
- 5.8
- Air lb/hr
- 345.5
- NH3 lb/min
- 4.4
- NH3 lb/hr
- 264.9
- R-22 lb/min
- 9.9
- R-22 lb/hr
- 596.9
- R-290 lb/min
- 7.1
- R-290 lb/hr
- 426.3
- R-404A lb/min
- 10.6
- R-404A lb/hr
- 634.2
- R-502 lb/min
- 3.6
- R-502 lb/hr
- 218.9
175
- Air SCFM
- 87.0
- Air lb/min
- 6.6
- Air lb/hr
- 398.4
- NH3 lb/min
- 5.1
- NH3 lb/hr
- 305.5
- R-22 lb/min
- 11.5
- R-22 lb/hr
- 688.3
- R-290 lb/min
- 8.2
- R-290 lb/hr
- 491.5
- R-404A lb/min
- 12.2
- R-404A lb/hr
- 731.2
- R-502 lb/min
- 4.2
- R-502 lb/hr
- 252.4
200
- Air SCFM
- 98.6
- Air lb/min
- 7.5
- Air lb/hr
- 451.3
- NH3 lb/min
- 5.8
- NH3 lb/hr
- 346.0
- R-22 lb/min
- 13.0
- R-22 lb/hr
- 779.6
- R-290 lb/min
- 9.3
- R-290 lb/hr
- 556.8
- R-404A lb/min
- 13.8
- R-404A lb/hr
- 828.3
- R-502 lb/min
- 4.8
- R-502 lb/hr
- 285.9
225
- Air SCFM
- 110.1
- Air lb/min
- 8.4
- Air lb/hr
- 504.1
- NH3 lb/min
- 6.4
- NH3 lb/hr
- 386.5
- R-22 lb/min
- 14.5
- R-22 lb/hr
- 871.0
- R-290 lb/min
- 10.4
- R-290 lb/hr
- 622.0
- R-404A lb/min
- 15.4
- R-404A lb/hr
- 925.4
- R-502 lb/min
- 5.3
- R-502 lb/hr
- 319.4
250
- Air SCFM
- 121.7
- Air lb/min
- 9.3
- Air lb/hr
- 557.0
- NH3 lb/min
- 7.1
- NH3 lb/hr
- 427.1
- R-22 lb/min
- 16.0
- R-22 lb/hr
- 962.3
- R-290 lb/min
- 11.5
- R-290 lb/hr
- 687.3
- R-404A lb/min
- 17.0
- R-404A lb/hr
- 1022.4
- R-502 lb/min
- 5.9
- R-502 lb/hr
- 352.9
275
- Air SCFM
- 133.2
- Air lb/min
- 10.2
- Air lb/hr
- 609.9
- NH3 lb/min
- 7.8
- NH3 lb/hr
- 467.6
- R-22 lb/min
- 17.6
- R-22 lb/hr
- 1053.7
- R-290 lb/min
- 12.5
- R-290 lb/hr
- 752.5
- R-404A lb/min
- 18.7
- R-404A lb/hr
- 1119.5
- R-502 lb/min
- 6.4
- R-502 lb/hr
- 386.4
300
- Air SCFM
- 144.8
- Air lb/min
- 11.0
- Air lb/hr
- 662.8
- NH3 lb/min
- 8.5
- NH3 lb/hr
- 508.2
- R-22 lb/min
- 19.1
- R-22 lb/hr
- 1145.1
- R-290 lb/min
- 13.6
- R-290 lb/hr
- 817.7
- R-404A lb/min
- 20.3
- R-404A lb/hr
- 1216.5
- R-502 lb/min
- 7.0
- R-502 lb/hr
- 420.0
325
- Air SCFM
- 156.3
- Air lb/min
- 11.9
- Air lb/hr
- 715.7
- NH3 lb/min
- 9.1
- NH3 lb/hr
- 548.7
- R-22 lb/min
- 20.6
- R-22 lb/hr
- 1236.4
- R-290 lb/min
- 14.7
- R-290 lb/hr
- 883.0
- R-404A lb/min
- 21.9
- R-404A lb/hr
- 1313.6
- R-502 lb/min
- 7.6
- R-502 lb/hr
- 453.5
350
- Air SCFM
- 167.9
- Air lb/min
- 12.8
- Air lb/hr
- 768.5
- NH3 lb/min
- 9.8
- NH3 lb/hr
- 589.2
- R-22 lb/min
- 22.1
- R-22 lb/hr
- 1327.8
- R-290 lb/min
- 15.8
- R-290 lb/hr
- 948.2
- R-404A lb/min
- 23.5
- R-404A lb/hr
- 1410.6
- R-502 lb/min
- 8.1
- R-502 lb/hr
- 486.9
375
- Air SCFM
- 179.4
- Air lb/min
- 13.7
- Air lb/hr
- 821.4
- NH3 lb/min
- 10.5
- NH3 lb/hr
- 629.8
- R-22 lb/min
- 23.7
- R-22 lb/hr
- 1419.1
- R-290 lb/min
- 16.9
- R-290 lb/hr
- 1013.4
- R-404A lb/min
- 25.1
- R-404A lb/hr
- 1507.7
- R-502 lb/min
- 8.7
- R-502 lb/hr
- 520.4
400
- Air SCFM
- 191.0
- Air lb/min
- 14.6
- Air lb/hr
- 874.3
- NH3 lb/min
- 11.2
- NH3 lb/hr
- 670.3
- R-22 lb/min
- 25.2
- R-22 lb/hr
- 1510.5
- R-290 lb/min
- 18.0
- R-290 lb/hr
- 1078.7
- R-404A lb/min
- 26.7
- R-404A lb/hr
- 1604.7
- R-502 lb/min
- 9.2
- R-502 lb/hr
- 554.0
| Set Pressure (PSIG) | Air SCFM | Air lb/min | Air lb/hr | NH3 lb/min | NH3 lb/hr | R-22 lb/min | R-22 lb/hr | R-290 lb/min | R-290 lb/hr | R-404A lb/min | R-404A lb/hr | R-502 lb/min | R-502 lb/hr |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 50 | 29.3 | 2.2 | 134.0 | 1.7 | 102.8 | 3.9 | 231.5 | 2.8 | 165.3 | 4.1 | 246.0 | 1.4 | 84.9 |
| 75 | 40.8 | 3.1 | 186.9 | 2.4 | 143.4 | 5.4 | 322.9 | 3.8 | 230.6 | 5.7 | 343.0 | 2.0 | 118.4 |
| 100 | 52.4 | 4.0 | 239.8 | 3.1 | 183.9 | 6.9 | 414.3 | 4.9 | 295.8 | 7.3 | 440.1 | 2.5 | 151.9 |
| 125 | 63.9 | 4.9 | 292.6 | 3.7 | 224.3 | 8.4 | 505.6 | 6.0 | 361.0 | 9.0 | 537.1 | 3.1 | 185.4 |
| 150 | 75.5 | 5.8 | 345.5 | 4.4 | 264.9 | 9.9 | 596.9 | 7.1 | 426.3 | 10.6 | 634.2 | 3.6 | 218.9 |
| 175 | 87.0 | 6.6 | 398.4 | 5.1 | 305.5 | 11.5 | 688.3 | 8.2 | 491.5 | 12.2 | 731.2 | 4.2 | 252.4 |
| 200 | 98.6 | 7.5 | 451.3 | 5.8 | 346.0 | 13.0 | 779.6 | 9.3 | 556.8 | 13.8 | 828.3 | 4.8 | 285.9 |
| 225 | 110.1 | 8.4 | 504.1 | 6.4 | 386.5 | 14.5 | 871.0 | 10.4 | 622.0 | 15.4 | 925.4 | 5.3 | 319.4 |
| 250 | 121.7 | 9.3 | 557.0 | 7.1 | 427.1 | 16.0 | 962.3 | 11.5 | 687.3 | 17.0 | 1022.4 | 5.9 | 352.9 |
| 275 | 133.2 | 10.2 | 609.9 | 7.8 | 467.6 | 17.6 | 1053.7 | 12.5 | 752.5 | 18.7 | 1119.5 | 6.4 | 386.4 |
| 300 | 144.8 | 11.0 | 662.8 | 8.5 | 508.2 | 19.1 | 1145.1 | 13.6 | 817.7 | 20.3 | 1216.5 | 7.0 | 420.0 |
| 325 | 156.3 | 11.9 | 715.7 | 9.1 | 548.7 | 20.6 | 1236.4 | 14.7 | 883.0 | 21.9 | 1313.6 | 7.6 | 453.5 |
| 350 | 167.9 | 12.8 | 768.5 | 9.8 | 589.2 | 22.1 | 1327.8 | 15.8 | 948.2 | 23.5 | 1410.6 | 8.1 | 486.9 |
| 375 | 179.4 | 13.7 | 821.4 | 10.5 | 629.8 | 23.7 | 1419.1 | 16.9 | 1013.4 | 25.1 | 1507.7 | 8.7 | 520.4 |
| 400 | 191.0 | 14.6 | 874.3 | 11.2 | 670.3 | 25.2 | 1510.5 | 18.0 | 1078.7 | 26.7 | 1604.7 | 9.2 | 554.0 |
