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General Pump ZK32 Flow Sensitive Unloader, 0-1500 PSI, 4.5 - 5.5 GPM

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1.80 lbs
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Flow-sensitive unloading valve with pressure adjusting screw, protecting your system from overpressure. Stainless and brass internal parts. 4.2 to 5.5 GPM, adjustable pressure from 0 PSI to 1500 PSI.

Technical Specifications

Min GPM: 4.2
Max GPM: 5.5
Min PSI: 0
Max PSI: 1500
Max Temperature: 165 degrees F
Inlet Port: 3/8 inch
Outlet Port: 3/8 inch
Bypass Port: 3/4 inch

Product Description

General Pump Flow Sensitive Unloader

The General Pump ZK31 flow sensitive unloader features a flow-through design, protecting your system from overpressure and spikes. Stainless and brass internal parts for durability, no external moving parts or springs for ease of use and reliability. Eliminates high pressure in all lines while unit is in bypass mode while also eliminating pressure peaks normally generated by conventionally designed unloaders. Unique balanced piston design permits precise pressure adjustment. Easy to maintain and service. Dual gauge ports - always use a pressure gauge when making adjustments! Best for single pump or Non weep guns.

Valves require a minimum of 5% by-pass at ALL times.

Dimensions: 5.75" x 3.50" x 2.75"


  • Volume Range: 4.2GPM - 5.5GPM
  • Pressure Range: 0PSI - 1500PSI
  • Inlet Port: 3/8" BSP-F
  • Bypass Port 3/4" BSP-M   
  • Outlet Port: 3/8" BSP-F
  • Max Temperature: 165°F

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