Aquatrol’s Series 69 is an industry-standard valve for liquid relief, liquid by-pass and over protection. Series 51 and 55 are generally used where size or spacing is a factor and in high-pressure settings.


  • Ruggedly constructed
  • Metal-to-metal/precision lapped seating
  • Closed hex cap
  • Factory set and sealed (also can be field adjusted)
  • Variety of inlet and outlet options
  • Fixed blowdown
  • Closed bonnet design to minimize leakage


  • Liquid relief and overprotection
  • By-pass relief
  • Continuous relief
  • Pressure regulation
  • Pumping systems, tanks and hydraulics
  • Fluid lines
  • Oil fields and chemical processing

Sizes: ¼” to 3”

Pressure and Temperature Limits:

  • Pressures to 600#
  • Temperatures to 450 degrees F°


  • Wheel handle
  • Variety of inlet and outlets
  • Stainless steel inserts for corrosive or higher pressure protection
  • Polishing and chrome plating