An American-made triplex plunger positive displacement pump with reciprocating plungers for direct or belt drive applications.

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), couplers (Aluminum or Delrin), unloader/regulator, fixed or adjustable chemical injector, thermal relief valve 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

  • P328 Exploded View
  • P328 Parts List
  • P328 Torque Specifications

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  • Giant Industries Limited Warranty
  • P328 Installation Instructions
  • P328 Repair Instructions
  • Troubleshooting Guide


U.S. Metric
3450 RPM
Flow 4.1 GPM 15.5 L/min
Nominal Pressure 3200 PSI 220 bar
Power Required (Nominal) 9.0 hp 6.7 kW
Intermittent Pressure 3500 PSI 240 bar
Power Required (Intermittent) 9.9 hp 7.4 kW
Maximum Inlet Pressure 145 PSI 10 bar
Maximum Temperature 160 °F 70 °C
Plunger Diameter 0.63″ 16 mm
Stroke 0.31″ 8.0 mm
Crankshaft Diameter 24 mm
Crankshaft Rotation Top of Pulley Towards Manifold
Crankshaft Mounting Either Side
Inlet Ports (2) 1/2″ BSP
Discharge Ports (2) 3/8″ BSP
Oil Capacity (short) 14.2 fl. oz. 0.42 L
Oil Capacity (extended) 17.0 fl. oz. 0.5 L
Weight 16 lbs. 7.3 kg
Key Component Material
Manifold Forged Brass
Plungers Solid Ceramic Oxide
Valves High Grade Stainless Steel
Seals Nitrile With Fabric Reinforcing
Gear End Aluminum Die-Cast

Click the image to enlarge


RPM GPM 1000 PSI 1500 PSI 2000 PSI 2500 PSI
500 0.13 0.1 0.1 0.2 0.2
1000 0.26 0.2 0.3 0.4 0.4
1750 0.46 0.3 0.5 0.6 0.8
3000 0.78 0.5 0.8 1.1 1.3
3200 0.83 0.5 0.9 1.1 1.4
3450 0.9 0.6 0.9 1.2 1.6

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 #0507
23 07767 Grooved Seal 3
23A 06315 Grooved Seal 3
24 07768 Pressure Ring 3
Valve Assembly Kit – Part #09116
31 07853 O-Ring 6
32x 07946A Valve Assembly Complete 6
33 07913 O-Ring 6
Oil Seal Kit – Part #09144
19 08356-0010 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.