GP7128

A German-made reciprocating triplex plunger pump.

Features:
Spheroidal cast iron crankcase with sight glass and vented dipstick; forged, through-hardened, ground and polished crankshaft; bronze connecting rods; hardened stainless steel plunger bases; stainless plungers with hardened metal coating; nitrile seals with fabric reinforcing; stainless steel valves and machined stainless steel manifold.

  • GP7128 Exploded View
  • GP7128 Parts List
  • GP7128 Torque Specifications
  • Giant Industries Limited Warranty
  • GP7128 Installation Instructions
  • GP7128 Repair Instructions
  • Troubleshooting Guide

SPECIFICATIONS

U.S. Metric
Max Flow 17.9 GPM 67.7 L/min
Max Discharge Pressure (Intermittent) 5800 PSI 400 bar
Max Speed (Intermittent) 750 RPM
Inlet Pressure 145 PSI 10 bar
Plunger Diameter 1.1″ 28 mm
Stroke 2.1″ 52 mm
Max Temp @ 1000 RPM 140 °F 60 °C
Crankshaft Diameter 48 mm
Crankcase Capacity 1.6 gal 6.0 L
Weight 375 lbs. 170 kg
Inlet Ports (2) 1-1/4″ BSP
Discharge Ports (2) 3/4″ BSP
Shaft Rotation Top of Pulley Towards Manifold
Shaft Mounting Either Side
Volumetric Efficiency @ 700 RPM 89%
Mechanical Efficiency @ 700 RPM 83%
Key Component Material
Manifold Stainless Steel
Plungers Stainless with Hardened Metal Coating
Valves Stainless Steel
Seals Nitrile with Fabric Reinforcing
Gear End Cast Iron

Click the image to enlarge


HORSEPOWER SPECIFICATIONS

RPM GPM 3000 PSI 4000 PSI 5000 PSI 5800 PSI
300 7.2 14.9 19.9 24.8 28.8
400 9.5 19.7 26.2 32.8 38.0
550 13.1 27.1 36.1 45.2 52.4
600 14.3 29.6 39.4 49.3 57.2
650 15.5 32.1 42.8 53.4 62.0
700 16.7 34.6 46.1 57.6 66.8
750 17.9 37.0 49.4 61.7 71.6

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

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.


REPAIR KITS

ITEM# PART# DESCRIPTION Qty.
Plunger Packing Kit – Part #09464
38A 12055 O-Ring, Seal case 3
38B 07693 Support Ring 3
38C 07354 O-Ring 3
38D 12056 Support Ring 3
39A 13228 Grooved Ring 3
42 13369 V-Sleeve 6
43 06862 Sleeve Support Ring 3
Valve Assembly Kit – Part #09520
51A 12056 Support Ring 6
51B 07354 O-ring 6
51C 13131 Inlet Valve Seat 3
51D 13130 Valve Plate 6
51E 07062 Valve Spring 6
52C 13149 Discharge Valve Seat 3
58A 07700 O-Ring 3
58B 07693 Support Ring 3
Oil Seal Kit – Part #09221
32 07624 Radial Shaft Seal 3
33A 07627 O-Ring 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.

PUMP CATEGORIES:
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.