803 Ductile Iron Safety Relief Valve, 1/2″ FNPT x 3/4″ FNPT

Item # 803-CYRUS Brand: Cyrus Shank

$190.33

Set pressure range: 50 to 400 PSIG.

Free Shipping for qualifying carts over $149+

Web Exclusive - Available online only

ASME
Visa, MasterCard, Discover, American Express, PayPal | TrustPilot | SSL Secure

The 803 relief valve has an angle style and a larger outlet size.

The ASME certified slope of 1.978 yields, for example, a capacity of 43.7 lbs. per minute of air @ 250psi set pressure.

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.

Features:

  • National Board Certification #: 51129
  • Set Pressure Range: 50-400 PSI in 25 PSIG increments
  • Traditional Primer Painted Casting

803 Series Capacity Chart

Slope = 1.978 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
50 137.9 10.5 631.5 8.1 484.1 18.2 1091.0 13.0 779.1 19.3 1159.0
75 192.3 14.7 880.6 11.3 675.1 25.4 1521.4 18.1 1086.5 26.9 1616.3
100 246.7 18.8 1129.7 14.4 866.2 32.5 1951.8 23.2 1393.9 34.6 2073.6
125 301.1 23.0 1378.9 17.6 1057.2 39.7 2382.3 28.4 1701.2 42.2 2530.9
150 355.4 27.1 1628.0 20.8 1248.2 46.9 2812.7 33.5 2008.6 49.8 2988.2
175 409.8 31.3 1877.1 24.0 1439.2 54.1 3243.1 38.6 2316.0 57.4 3445.5
200 464.2 35.4 2126.3 27.2 1630.2 61.2 3673.6 43.7 2623.4 65.0 3902.8
225 518.6 39.6 2375.4 30.4 1821.2 68.4 4104.0 48.8 2930.8 72.7 4360.1
250 573.0 43.7 2624.5 33.5 2012.2 75.6 4534.4 54.0 3238.2 80.3 4817.4
275 627.4 47.9 2873.7 36.7 2203.3 82.7 4964.9 59.1 3545.6 87.9 5274.7
300 681.8 52.0 3122.8 39.9 2394.3 89.9 5395.3 64.2 3852.9 95.5 5731.9
325 736.2 56.2 3372.0 43.1 2585.3 97.1 5825.7 69.3 4160.3 103.2 6089.2
350 790.6 60.4 3621.1 46.3 2776.3 104.3 6256.2 74.5 4467.7 110.8 6646.5
375 845.0 64.5 3870.2 49.5 2967.3 111.4 6686.6 79.6 4775.1 118.4 7103.8
400 899.4 68.7 4119.4 52.6 3158.3 118.6 7117.0 84.7 5082.5 126.0 7561.1

Additional information

Brand Cyrus Shank
Weight 3.3 lbs
Set pressure

, , , , , , , , , , , , ,

NB Certificate

Max Working Pressure

Temperature range

Material

Size

Item Type

Item #Description
803-50Set pressure: 50
803-75Set pressure: 75
803-100Set pressure: 100
803-125Set pressure: 125
803-150Set pressure: 150
803-175Set pressure: 175
803-200Set pressure: 200
803-225Set pressure: 225
803-250Set pressure: 250
803-275Set pressure: 275
803-300Set pressure: 300
803-325Set pressure: 325
803-350Set pressure: 350
803-375Set pressure: 375
803-400Set pressure: 400