Series 36/37

High PerformanceKeystone

The Keystone Series 36/37 High Performance Butterfly Valve just got better with the launch of the all new Double Flanged body. Customers in the oil and gas market now have a comprehensive range of body style choices with Keystone’s classic high cycle life and lower cost of ownership. The Double Flanged Butterfly Valve extends the product line, which already includes wafer and lug style versions.

Primarily designed to meet the stringent requirements and safety levels of the oil & gas industry, this high performance butterfly valve is available in a range of sizes, from 3 inches to 24 inches (DN 80-600). This makes them ideally suited for a host of applications, including firewater, hydrocarbons, cargo handling, bilge and ballasts and utilities, just to name a few. 

Manufactured to ASME 150 and 300 standards, the Series 36/37 Double Flanged Butterfly Valve features a soft polymer seat. Customers can specify PTFE, RTFE or UHMWPE seats, depending on their application and the performance characteristics required.

The new valve is available in a choice of body materials – carbon steel for general applications, 316 stainless steel and duplex stainless steel for applications requiring superior corrosion resistance.

K-LOK Series 36 - ASME 150 K-LOK Series 37 - ASME 300

• Modulating service • Airport refueling • Hydrocarbon processing • Chemical/petrochemical processing • Purified gas • Steam and vacuum services • Power and utilities • Refrigeration • HVAC • Alumina refining

  • K-LOK polymer and elastomer seats provide bi-directional, drop-tight shut-off in vacuum as well as at full rated differential pressure. Its unique design does not rely on pressure to assist sealing therefore seals at high and low pressures, as well as dirty services. A variety of materials allows optimum seat life in all applications.
  • Blow-out resistant shaft is standard on all valves for increased safety.
  • Unique packing design allows for use in pressure as well as vacuum without modification or special assembly.
  • Disc taper pins are tangentially positioned half in disc and half in shaft, placing them in compression rather than shear, which eliminates potential for failure.
  • Rocker-shaped gland bridge compensates for uneven adjustment of gland nuts reducing packing leaks.
  • Integrally cast disc position stop perfectly locates the disc in seat, achieving maximum seat and seal life.
  • Extended neck allows for 50 mm (2") of pipeline insulation.
  • Integrally cast mounting pad provides direct mounting of actuators eliminating the need for costly brackets and couplings.
  • Flattened body bore at shaft journal ports positions shaft bearings near disc, providing maximum shaft support resulting in reduced wear and longer life.

Technical Data




Up to ASME 300


-40°F - +1000°F


NPS 2-24


Polymer seats



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