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.

  • P455B Exploded View
  • P455B Parts List
  • P455B Torque Specifications
  • Giant Industries Limited Warranty
  • P455B Installation Instructions
  • P455B Repair Instructions
  • Troubleshooting Guide


U.S. Metric
1450 RPM
Max Flow 5.5 GPM 20.8 L/min
Max Discharge Pressure (Continuous) 4350 PSI 300 bar
Max Discharge Pressure (Intermittent) 5075 PSI 350 bar
Max Inlet Pressure 145 PSI 10 bar
Plunger Diameter 0.71″ 18 mm
Stroke 0.79″ 20 mm
Max Temp 158 ºF 70 °C
Crankshaft Diameter 1.10″ 28 mm
Key Width 0.32″ 8 mm
Weight 38.3 lbs. 17.4 kg
Crankcase Capacity 30.4 fl. oz. 0.9 L
NPSHR 28.5 Ft. of Head 8.7 meters of Head
Inlet Ports (2) 3/4″ BSP
Discharge Ports (2) 3/4″ BSP
Shaft Rotation Top of Pulley
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 2000 PSI 3000 PSI 4350 PSI 5075 PSI*
920 3.5 4.8 7.2 10.5 12.2
1050 4.0 5.5 8.3 12.0 14.0
1185 4.5 6.2 9.3 13.5 15.8
1315 5.0 6.9 10.3 15.0 17.5
1450 5.5 7.6 11.4 16.5 19.3

*Intermittent duty only!

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

as 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 #09141
21 07266 O-Ring 3
23 08477 V-Sleeve 6
24 07929 Pressure Ring 3
Valve Assembly Kit – Part #09644
27A 05543 Valve Assembly, Complete 6
33 05545 O-Ring 6
Oil Seal Kit – Part #09641
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.