A German-made reciprocating triplex plunger pump.

Aluminum crankcase with sight glass and vented dipstick; forged, through-hardened, ground and polished crankshaft; bronze connecting rods; hardened stainless steel plunger bases; solid ceramic plungers; nitrile seals (with fabric reinforcing); stainless steel valves; and forged brass manifold.

Gearbox and bell housings (to connect to gasoline, diesel, electric or hydraulic drive) and pulsator valve.

WARNING: This product might contain a chemical known to the State of California to cause cancer, and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov

  • P422HP Exploded View
  • P422HP Parts List
  • P422HP Technical Drawing
  • Giant Industries Limited Warranty
  • P422HP Installation Instructions
  • P422HP Repair Instructions
  • Troubleshooting Guide


U.S. Metric
Flow 9.9 GPM 37.3 L/min
Max Discharge Pressure 4060 PSI 280 bar
Max Inlet Pressure 145 PSI 10 bar
Max Speed 1450 RPM
Plunger Diameter 0.87″ 22 mm
Stroke 0.94″ 24 mm
Max Temp 158 °F 71 °C
Crankshaft Diameter 1.10″ 28 mm
Key Width 0.32″ 8 mm
Weight 42 lbs. 19 kg
Crankcase Capacity 30.4 fl. oz. 0.9 L
NPSHR 32.8 Ft.-Head 10.0 mWs
Inlet Ports (1) 1″ BSP, (2) 3/4″ BSP
Discharge Ports (2) 3/4″ BSP
Shaft Rotation Top of Pulley Towards Manifold
Shaft Mounting Either Side
Key Component Material
Manifold Forged Brass
Plungers Solid Ceramic Oxide
Valves High Grade Stainless Steel
Seals Nitrile With Fabric Reinforcing
Gear End Aluminum

Click the image to enlarge


RPM GPM 1000 PSI 2000 PSI 3000 PSI 4060 PSI
900 6.1 4.2 8.4 12.6 17.1
1050 7.2 5.0 10.0 15.0 20.3
1160 7.9 5.4 10.9 16.3 22.1
1300 8.9 6.1 12.3 18.4 24.9
1450 9.9 6.8 13.7 20.5 27.7

Horsepower Requirements

The ratings shown are the power requirements for the pump. Gas engine power outputs must be approximately twice the pump power requirements shown above.

We recommend a 1.15 service factor be specified when selecting an electric motor as the power source. To compute specific pump horsepower requirements use the following formulas:
Electric HP = (GPM X PSI)/1450
Gas HP = (GPM X PSI)/1100

*Engine power varies based on horizontal or vertical orientation, as well as by makes and models from each manufacturer.


Plunger Packing Kit – Part #09723
20A 07266 O-Ring 3
21A 07281 O-Ring 6
21B 05967 Support Ring 6
23 06249 V-Sleeve w/Support Ring 3
23B 13390 Weep Seal 3
24 06252 Pressure Ring 3
25B 02009 O-Ring 2
Valve Assembly Kit – Part #09724
27A 06936 Valve Assembly, Complete 6
33 05972 O-Ring 6
Oil Seal Kit – Part #09144
19 05444 Oil Seal 3

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.