Harben Water Pumps

A revolutionary pump design when it was developed 35-years ago, Harben’s radial piston diaphragm pumps have established a worldwide track record of proven performance in a multitude of industrial, maritime and pipe cleaning applications.

In addition to the original “P” pump design, Harben now offers Century and Hi-Q pumps for specialized commercial and industrial applications.

“P” Pump

The value of high pressure, low flow jetting in the sewer and drain cleaning industry has been proven by the combination of “P” pump reliability, long service intervals, smaller, less costly jetting platforms and reduced power requirements. Learn more.

By dramatically reducing the volume of water required to efficiently clean sewer and drain lines, users have been able to mount light weight, compact jetting units on light duty trucks, easily towed trailers, portable carts and towable skids.

There are several versions of the successful “P” pump that allow users to match pump flow rates, power requirements and output pressure to specific applications. As a group, these “P” pumps develop pressure and flow rate combinations ranging from 4 to 18 gpm at pressures up to 6,000 psi.


  • 5-year warranty standard when used in sewer and drain cleaning operations
  • Save with “P” pump reliability, long service intervals and reduced equipment downtime
  • Run “P” pumps dry--indefinitely
  • Clean efficiently with constant pressure and flow
  • Pump sea water and other fluids
  • Pulsate on demand

Learn more about “P” pump quality and operating value


“P” pumps are used throughout the world in many diverse applications. Here are a few:

  • Sewer and drain cleaning.  Learn more
  • Surface and floor cleaning
  • Tube descaling
  • Abrasive blasting, precision cutting and machining
  • Underwater cleaning and removal of marine growth

Power requirements

Typically application driven, customers have chosen to power “P” pumps by the following methods:

  • Independent, auxiliary diesel engines coupled with gear reduction boxes. This is the conventional source of power preferred by most customers for sewer jetting and drain cleaning applications.  Learn more
  • PTO drive systems. Truck and service vehicles may benefit from PTO drive systems. Contact us for engineering assistance.
  • Electric motors. For commercial and industrial applications outside the sewer and drain cleaning industry, 3 phase, 460 volt power systems are convenient, environmentally safe alternatives to diesel engine power. Contact us for assistance.

Century Pump

Produced in six models, the Century pump allows industrial and commercial users to achieve numerous pressure and flow combinations suited for specific applications up to 10,000 psi and up to 38 gpm.

With any of the six Century pump models, pressure and flow rates may be adjusted simply by changing the nozzle. For example, the 825.019 pump produces 32 gpm at 2,000 psi; change the nozzle and the output is 20 gpm at 10,000 psi.

Depending on pump output, Century pumps typically require diesel engines delivering 100 bhp to 167 bhp. Heavy duty, 3 phase 420 volt electric motors are an option for industrial users.  Learn more

Hi-Q Pump

The newest Harben radial piston diaphragm pump is the “Hi-Q”—a four barrel design with a continuous duty performance rating of 25 gpm at 4,000 psi.

Weighing just 298 pounds, this compact, higher volume pump measures just 20.5-inches deep and 19.8-inches side-to-side. The power input requirement at full rated pump capacity is 65 bhp, plus a 10% recommended reserve.

Documents downloadable in Adobe pdf format:

Harben 8 barrel "P" pump

Click on product photos to enlarge  (Image 1)

Harben 8 barrel "P" pump
Harben direct drive powered "P" pump assembled with a shrouded gear box anbd diesel engine
Harben "P" pump with crankcase cover and barrel nuts removed
Harben 6-barrel "P" pump crankcase interior
Harben 4 barrel "P" pump powered by a 20 h.p., 3-phase, 460 volt motor
Harben 4 barrel "P" pump assembled with 1/4" lateral hose for tube cleaning

Captions below refer to images above, in left to right order

  • 8 barrel "P" pump. Peak performance ratings up to 18 gpm; up to 4,000 psi
  • Direct drive powered "P" pump assembled with a shrouded gear box and diesel engine
  • "P" pump with crankcase cover and barrel nuts removed. Picture shows a stainless steel barrel assembled with a delivery check valve
  • 6-barrel pump crankcase interior. Picture shows barrels partially assembled. The 6-barrel design delivers up to 12 gpm and up to 4,000 psi
  • 4 barrel "P' pump. Assembled with a 20 h.p., 3-phase, 460 volt motor. Mounted on a collapsable skid. Peak performance ratings: 4.5 gpm at 6,000 psi. Control panel and 16 gallon water tank mounted on separate standalone platforms.
  • 4 barrel "P" pump assembled with 1/4" lateral hose for tube cleaning.

How a Rotary Piston Pump Works:

Each stainless steel barrel holds a resilient rubber diaphragm that is blocked at opposite ends by a poly check valve. Water enters and leaves the diaphragm through these two check valves.

As the offset pump shaft rotates, pistons connected to the shaft enter each barrel sequentially through a port machined in the side of the barrel. As a piston enters each barrel, the piston draws oil from the oil filled pump case and presses it into the barrel.

This action squeezes the rubber diaphragm and forces water out one of the two check valves, known as the "delivery" valve.

In effect, the action is like squeezing a cow's udder. Finally, as each piston withdraws sequentially from the corresponding barrel, water is drawn into the rubber diaphragm through the inlet check valve. It's a straightforward, simple to understand and easy-to-maintain pump.