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CAT Pumps 56 Brass Head 5.5 GPM 7 Frame Plunger Pump - 3500 PSI

Model 56 CAT Pumps 5.5 GPM Triplex PumpTop Seller
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30.40 lbs
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Seven frame plunger pump with a steel crankcase and a brass manifold. 1/2" x 3/8" F ports. Max 5.5 GPM and 3500 PSI. Rails sold separately.

Technical Specifications

Bore: 18 millimeter
Crankcase Capacity: 25 ounce
Inlet Port: 1/2 inch
Max GPM: 5.5
Shaft Diameter: 24 millimeter
Stroke: 24 millimeter
RPM: 1210
Max Temperature: 160 degrees F
Max PSI: 3500

Product Description

1200 RPM High-Pressure Triplex Plunger Pump

This CAT Pumps 56 model pump is rated for a flow up to 5.5 gpm at 3500 PSI pressure. The model 56 brass manifold pump includes 1/2" female NPT inlet ports and 3/8" female NPT outlet ports. Use this strong, high-efficiency triplex pump for car wash systems, desalination, chemical injection, and more!

The 56 CAT model is a triplex type plunger pump with a 304 stainless steel housing, ceramic solid plungers, and a brass forged manifold that is strong and corrosion-resistant. CAT triplex pumps are precisely engineered and designed for smoother liquid flow, extended life, and unmatched durability - even at high pressure levels.


  • 5.5 GPM flow rate
  • 3500 PSI maximum pressure
  • 100-3500 PSI pressure range
  • 24mm stroke (.945")
  • 24mm shaft (.945")
  • 18mm bore (.708)
  • 25 oz. crankcase capacity
  • 1210 RPM
  • 1/2" NPT-F inlet port
  • 3/8" NPT-F outlet port
  • 160° F maximum liquid temperature
  • 7 frame style
  • Flooded to 60 PSI inlet pressure range


  • 13.93" x 8.2" x 6.41"


Superior Design:

  • Triplex plunger design provides smoother liquid flow.
  • Hi-Pressure Seals are completely lubricated and cooled by the liquid being pumped.
  • Inlet and discharge valve assemblies interchange for easier maintenance.
  • Lubricated Lo-Pressure Seals provide double protection against external leakage.
  • Oil bath crankcase assures optimum lubrication.
  • Close tolerance concentricity of the ceramic plunger maximizes seal life.

Quality Materials:

  • Precision design 304 stainless steel valves and seats are hardened and polished for ultimate seating & extended valve life.
  • Brass manifold is strong and corrosion resistant.
  • Special concentric, high-density, polished, solid ceramic plungers provide a true wear surface and extended seal life.
  • Specially formulated, Hi-Pressure Seals offer unmatched performance & seal life.
  • Die cast aluminum crankcase provides high strength, minimum weight and precision tolerance control.
  • Chrome crankshaft gives unmatched strength and surface hardness.
  • Oversized crankshaft bearings with greater capacity mean longer bearing life.

Easy Maintenance:

  • Wet-end is easily serviced without entering crankcase, requiring less time and effort.
  • Preset packings mean no packing gland adjustment is necessary, reducing maintenance costs.

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