
Safety Relief Valves
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
assembly options
ASME Certified
UV & NB stamped
100% Tested
Every valve, every time
American Made
Manufactured since 1912
| Part # | NB Cert. # | Body Material | Wt (lbs) | Size |
|---|---|---|---|---|
| 800 | 51163 | A36 Carbon Steel Black Oxide Coated | 3.2 | ½” MNPT inlet x ¾” FNPT outlet |
#800 safety relief valve can be mounted on the following manifolds:
| 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. | All Cyrus Shank relief valves are manufactured in accordance with ASME Boiler and Pressure Vessel Code Section VIII Division I and stamped with the ASME Certification Mark with UV Designator. All Cyrus Shank relief valve capacities are certified by the National Board of Boiler and Pressure Vessel Inspectors and stamped with the NB Certification Mark. |
| 800 Series Capacity Chart Slope = 0.42 SCFM/PSIA Standard Conditions [60 ˚ F, 1 Atm] | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 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 |
| 50 | 29.3 | 2.2 | 134.1 | 1.7 | 102.8 | 3.9 | 231.6 | 2.8 | 165.4 | 4.1 | 246.1 |
| 75 | 40.8 | 3.1 | 187.0 | 2.4 | 143.4 | 5.4 | 323.0 | 3.8 | 230.7 | 5.7 | 343.2 |
| 100 | 52.4 | 4.0 | 239.9 | 3.1 | 183.9 | 6.9 | 414.4 | 4.9 | 296.0 | 7.3 | 440.3 |
| 125 | 63.9 | 4.9 | 292.8 | 3.7 | 224.5 | 8.4 | 505.8 | 6.0 | 361.2 | 9.0 | 537.4 |
| 150 | 75.5 | 5.8 | 345.7 | 4.4 | 265.0 | 10.0 | 597.2 | 7.1 | 426.5 | 10.6 | 634.5 |
| 175 | 87.0 | 6.6 | 698.6 | 5.1 | 305.6 | 11.5 | 688.6 | 8.2 | 491.8 | 12.2 | 731.6 |
| 200 | 98.6 | 7.5 | 451.5 | 5.8 | 346.2 | 13.0 | 780.0 | 9.3 | 557.0 | 13.8 | 828.7 |
| 225 | 110.1 | 8.4 | 504.4 | 6.4 | 386.7 | 14.5 | 871.4 | 10.4 | 622.3 | 15.4 | 925.8 |
| 250 | 121.7 | 9.3 | 557.3 | 7.1 | 427.3 | 16.0 | 962.8 | 11.5 | 687.6 | 17.0 | 1022.9 |
| 275 | 133.2 | 10.2 | 610.2 | 7.8 | 467.8 | 17.6 | 1054.2 | 12.5 | 752.8 | 18.7 | 1120.0 |
| 300 | 144.8 | 11.1 | 663.1 | 8.5 | 508.4 | 19.1 | 1145.6 | 13.6 | 818.1 | 20.3 | 1217.1 |
| 325 | 156.3 | 11.9 | 716.0 | 9.1 | 548.9 | 20.6 | 1237.0 | 14.7 | 883.4 | 21.9 | 1314.2 |
| 350 | 167.9 | 12.8 | 768.9 | 9.8 | 589.5 | 22.1 | 1328.4 | 15.8 | 948.7 | 23.5 | 1411.3 |
| 375 | 179.4 | 13.7 | 821.8 | 10.5 | 630.1 | 23.7 | 1419.8 | 16.9 | 1013.9 | 25.1 | 1508.4 |
| 400 | 191.0 | 14.6 | 874.7 | 11.2 | 670.6 | 25.2 | 1511.2 | 18.0 | 1079.2 | 26.8 | 1605.5 |