WPRV Williams Pressure Reducing Valves

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The Williams Fire & Hazard Control Pressure Reducing Valve (WPRV) maintains constant pre-set inlet pressure for use in conjunction with the Around The Pump (or comparable) foam systems. It allows any firewater pump to produce suction side foam at virtually any positive inlet pressure. Therefore, the WPRV eliminates the need for operator intervention to adjust intake gate valves, in response to suction pressure fluctuations as a result of changes in pump discharge flow. As a result, the added burden of assuring a maximum pump intake pressure (based on pump discharge pressure) associated with traditional suction side foam systems is eliminated, freeing up precious firefighting personnel resource to engage in more critical tasks.

Designed to work with compressed air foam systems and balanced pressure foam system, the WPRV can provide reduced pump inlet pressures to allow increased engine/power take off speed for maintaining higher compressor or foam pump output when operating with positive pump inlet pressures.  In addition, when installed within a discharge line, the WPRV maintains a preset pressure for hand lines or ground monitors regardless of higher pump discharge pressures.

Features & Benefits

  • Three Modes of Operation:
    • Automatic – Controls pre-set pressure from 15  - 115 psi (1.0 – 7.9 bars)
    • Open – Full flow to rated capacity:
      • WPRV/3 – 500 gpm (1,893 Lpm) w/ 7 psi (0.5 bars) drop
      • WPRV/4 – 1,500 gpm (5,678 Lpm) w/ 20 psi (1.4 bars) drop
    • Closed – Bubble tight shut off
  • NFPA 1901, 14-6 compliant – Exclusive WPRV pilot control also provides bubble tight shut off to comply with NFPA 1901,19-3.6, TIA 99-1 preventing foam solution back flow into a potable (hydrant system) water supply
  • Pressure ratings – 230 psi (15.9 bars) max. and 20 psi (1.4 bars) Min. (prevents reducing hydrant system pressures below 20 psi or 1.4 bars)
  • Inlet/outlet – WPRV/3: 2.5” NST; WPRV/4: 5” Storz

Materials of Construction

WPRV/3 & 3P – Epoxy coated cast iron w/brass and stainless steel trim
WPRV/4 & 4P – Epoxy coated & anodized aluminum w/brass and stainless steel trim

Available Options

WPRV/3 & 3P (Portable)

  • “In-Truck” installation with panel mount control valve, standard 2.5” (F)NST swivel inlet w/ strainer and bleeder port
  • 3” NST inlet w/strainer/outlet
  • 4” Storz inlet w/strainer/outlet

WPRV/4 & 4P (Portable)

  • “In-Truck” installation with panel mount control valve, standard 5” Storz inlet w/strainer, adjustable intake relief, bleeder port and mounting hardware
  • Inlet intake relief valve & bleeder (4P)
  • 4” Storz inlet w/strainer/outlet
  • 6” (F)NST swivel outlet for direct mounting to pump intakes
  • Inlet/outlet pressure gauges
  • Carrying handle
  • 5” LDH X 10’ (3 m) Long with 5” Storz couplings (200 psi or 13.8 bars operating pressure)

Ordering information

Send inquiries to Williams Fire & Hazard Control with your specific application requirement for custom configuration.