Cat Pump 45 Plunger Pump – 5 Frame Triplex, Model 45
The Cat Pump 45 is a 5 frame triplex plunger pump built for operations that run hard and cannot afford downtime. It moves up to 4.5 GPM and holds pressure anywhere from 100 to 3500 PSI at 1645 RPM, which puts it in the sweet spot for compact high pressure systems that still need real duty-cycle stamina. Three ceramic plungers running in a forged brass manifold keep flow smooth and pulsation low, so downstream nozzles, membranes, and injectors see steady pressure instead of hammering.
What makes the model 45 last is the way it handles heat and wear. The V-packings are lubricated and cooled by the liquid being pumped, and a second set of lubricated low-pressure seals stands behind them as a backup against external leakage. Below that, an oil bath crankcase with a chrome-moly crankshaft and high-strength connecting rods carries the load, while the close-tolerance ceramic plungers ride true through every stroke. Practically speaking, that means longer seal life and a wet end you can service without ever opening the crankcase.
You will find the 45 working in pressure washing and vehicle wash systems, reverse osmosis and desalination skids, hydrostatic test benches, misting and humidification, chemical injection, industrial parts cooling, agricultural spraying, and fire suppression packages. It accepts belt, clutch, flexible coupling, and bellhousing drives with a 20 mm solid shaft, so it drops into new builds and retrofits alike. At just under 21 pounds and roughly 12 inches long, it fits tight machine footprints where a larger frame simply will not go.
Key Features
- Triplex plunger design delivers smooth, low-pulsation flow
- Solid ceramic plungers, high-density and polished, for extended seal life
- Forged brass manifold with 304 stainless steel valves and seats
- V-packings lubricated and cooled by the pumped liquid
- Lubricated low-pressure seals give double protection against external leakage
- Oil bath crankcase for optimum lubrication under continuous duty
- Interchangeable inlet and discharge valve assemblies simplify parts stocking
- Wet end serviceable without entering the crankcase
- Compact 5 frame footprint for tight equipment packages
- Accepts belt, clutch, flexible coupling, and bellhousing drive configurations
Applications
- Pressure washing and vehicle wash systems
- Reverse osmosis and desalination systems
- Hydrostatic pressure testing
- Misting, fogging, and humidification
- Chemical injection and metering
- Industrial machine and parts cooling
- Agricultural and horticultural spraying
- Fire suppression and mist systems
- Surface preparation and industrial washdown
- Water treatment and boiler feed duty
Specifications
- Model: 45
- Frame: 5 Frame
- Pump Type: Triplex positive displacement reciprocating plunger
- Volume: 4.5 GPM (17 LPM)
- Discharge Pressure Range: 100 – 3500 PSI (6.9 – 241 BAR)
- Pump RPM: 1645
- Inlet Pressure: Flooded to 60 PSI (4.1 BAR)
- Inlet Port Size: 1/2" NPT (F), two ports
- Discharge Port Size: 3/8" NPT (F), two ports
- Bore: 0.630" (16 mm)
- Stroke: 0.708" (18 mm)
- Shaft Diameter: 0.787" (20 mm) solid shaft
- Crankcase Oil Capacity: 18 oz (0.53 L)
- Maximum Liquid Temperature: 160°F (71°C) with NBR seals; higher-temp seal options available
- Manifold: Forged brass
- Valves and Seats: 304 stainless steel, hardened and polished
- Plungers: Solid ceramic
- Crankcase: Die-cast aluminum
- Crankshaft: Chrome-moly
- Seals and O-Rings: NBR standard; FPM and PTFE options
- Drive Options: Belt, clutch, flexible coupling, bellhousing
- Approximate Horsepower Required: 4.6 HP at 1500 PSI, 6.2 HP at 2000 PSI, 7.7 HP at 2500 PSI, 9.3 HP at 3000 PSI, 10.8 HP at 3500 PSI
- Dimensions: 11.99" x 8.54" x 5.47" (305 x 217 x 139 mm)
- Weight: 20.9 lbs (9.5 kg)
Frequently Asked Questions
Q: Can the Cat Pump 45 be run at a lower pressure than 3500 PSI?
A: Yes. The model 45 is rated across a 100 to 3500 PSI range, and pressure is set by the regulating or unloader valve in your system rather than by the pump itself. Running below maximum reduces horsepower draw and generally extends packing life.
Q: Does the model 45 need to be primed or can it run dry?
A: It must never run dry. The V-packings depend on the pumped liquid for lubrication and cooling, so the inlet should be flooded or supplied at up to 60 PSI before startup, and the system should be protected against loss of supply.
Q: What direction can the pump shaft rotate?
A: The 20 mm solid shaft on the standard model 45 runs in one direction as supplied. If your drive layout requires the opposite hand, a reverse-shaft version of the same 5 frame pump is offered rather than reversing this one.
Q: How often should the crankcase oil be changed?
A: An initial oil change is recommended shortly after break-in, followed by scheduled changes based on run hours and operating conditions. The crankcase holds 18 oz, and using the manufacturer's specified pump oil is important for bearing and crankshaft life.
Q: Can it pump liquids other than water?
A: It handles many light-viscosity fluids beyond fresh water, including seawater, RO reject, and mild chemical solutions, provided the seal and valve materials suit the fluid. Standard NBR seals cover general water service, while FPM or PTFE options are selected for more aggressive chemistries.
CLRMarine
