Aquatrol's new Series 740 safety and relief valve is designed for accuracy and reliability. Engineered for heavy-duty industrial usage. Multiple purpose safety and relief valve for all services: Liquid, Steam and Air/Gas. ASME and National Board Certified for Section VIII service. Pressures are to 750 PSI. Available with the full array of metal and seating options.

Series 740

Brass, bronze construction with stainless steel ring, disk and springs. ASME Section VIII to 300 PSI for air/gas and liquid and 250 PSI for steam services.

Series 741

Stainless steel nozzle, ring, disk and springs. Bronze bonnet, and body. ASME Section VIII to 750 PSI for air/gas and liquid, 300 PSI for Steam.

Series 742

Stainless steel nozzle, ring, disk and springs. Carbon steel body and bonnet. Ratings same as 741. Used as an all steel option.

Series 743

Same as 742, with stainless steel bonnet, body and components. Used where a stainless steel valve is required.


Pressure Vessels, Pumps, Hydraulics, Tanks, Steam Systems, Chemical, Cryogenic, Air and Gas Compressors, Separators, by-pass and over pressure protection. Choose for most industrial applications requiring a safety relief valve.


  • Full nozzle – top guided design
  • Short, precise blow-down
  • Wide choice of inlet/outlet sizes
  • Excellent reseating characteristics
  • Designed for heavy industrial use
  • Closed hex cap
  • Back pressure tight
  • Drainhole with threaded plug
  • Cryogenic Compatible


  • O-ring seating options (see charts)
  • Packed lift lever
  • Open lift lever
  • BSPT piping
  • Full array of metal options
  • O2 Cleaning





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