This is a pressure-actuated unloader that is designed for any pump that fits within the flow and pressure range of the unloader. The unloader regulates the flow in the system and maintains system pressure via an adjustable nut that controls the amount of tension on a pressure spring. When no flow is going out the outlet port, all flow is diverted to the bypass port at virtually no pressure. The unloader is capable of handling one or more shut-off guns and should be run with no bypass (if the full flow from the pump is going through the unloader). It actuates at around 10% above the system pressure.

  • Giant Industries Limited Warranty
  • 22971CH Unloader


U.S. Metric
Flow (Maximum) 35.7 GPM 135 L/min
Flow (Minimum) 2.1 GPM 8 L/min
Pressure (Maximum) 580-1740 PSI 40-120 bar
Continuous Temperature 158 ºF 70 ºC
Inlet 3/4″ FNPT
Outlet 3/4″ FNPT
Bypass 3/4″ BSP
Weight 6.7 lbs 3.0 kg
Materials Brass


Repair Kit – Part #09461
2A 12241 Guide Ring 1
3 12057 O-Ring 1
6 12204 O-Ring, Valve Stem 1
7 12205 Back Up Ring, Valve Stem 1
9 05005 Cup, 28MM 1
10 05015 Back Up Ring, 28MM 1
11 12207 Ball 1
12 12216 Valve Spring 1
12A 12208 Seat, Inlet 1
14 12244 Valve Plate 1
14C 07035 O-Ring 2
14D 06017-0100 Spring, Outlet Valve 1
19A 12017 O-Ring, Plug 4

Repair Kits Available

The repair kits listed to the right are available for this pump. If you need further information about these repair kits, or have questions about other specific parts for your pump, please contact you local Giant distributor or contact Giant customer service.

Service & Repair

Giant provides service on each pump and accessory that we sell. Many basic repair procedures are covered in the Giant repair manual. For all other questions on service or repair needs please contact your local Giant distributor.