Why Buy Harben “P” Pumps?


5-year “P” pump warranty—standard

When used in sewer and drain cleaning operations, major components of the “P” pump are warranted for 5-years, allowing users to avoid unanticipated pump repair expenses and service interruptions.

Reduced parts wear means reduced downtime

Unlike reciprocating pumps, Harben pumps avoid exposing wear components to the abrasive and corrosive effects of high pressure water. “P” pumps have no piston or plunger packing to overheat, dry out or wear. At no time does water act on valve plates, seats or springs common in triplex and multiplex pumps.

Conventional reciprocating pressure pumps use pistons or plungers to draw water into water manifolds and, on return strokes, force pressurized water against spring loaded discharge check valves. Regardless of water quality, repetition of this action at high speeds causes valves, valve seats, springs, “O” rings, seals and packing to wear.

Instead of relying on pistons to compress water against machined spring loaded valve assemblies, Harben “P” pumps compress oil around water filled diaphragms. When compressed, water is squeezed from the diaphragms, past check valves and into high pressure hoses.  Learn more

Jet efficiently with constant pressure and flow

Designed with as many as eight barrel-shaped chambers, each containing a synthetic, composite rubber diaphragm, “P” pumps develop flow rates ranging 4-18 gpm at pressures up to 6,000 psi. Pistons act sequentially to compress water in each of these diaphragms at rates exceeding 1,000 strokes per minute.

The result is smooth, vibration free jetting at constant pressure and flow rates that optimize the performance of nozzles and cutting tools.  Learn more

Power end linkage from the engine is cushioned direct drive. There is no water pump drive belt or sprocket to replace or adjust. Noise and vibration is suppressed and maintenance substantially reduced.

Run dry without damage—indefinitely

"P" pumps are not damaged if allowed to "run dry" indefinitely - even at maximum power for days or weeks at a time.

Harben pumps rely on oil, not water, to cool and lubricate pump components. Diaphragms are not damaged if compressed without water—even for excessively long periods of time. Diaphragms simply vent compressed air through check valves—there are no parts to lubricate or cool with water.

Pump sea water and other fluids

Harben pumps are able to draw and expel a variety of fluids through the composite synthetic rubber diaphragms used in rotary piston pumps. Pump reclaimed water, sea and brackish water, many solvents and diesel fuel.

This feature contributes to the pump's versatile application in a diverse array of industrial, marine and commercial applications. For example, Harben pumps installed on U.S. and U.K. nuclear powered submarines use sea water to clean reactor cooling tubes.

"Jump Jet" Pulsation—on demand

“P” pump crankshafts rotate at 1,000 to 1,200 rpm, reliably creating constant pressure and flow. However, if an operator elects to divert water from two of the barrels away from the jetter's high pressure hose and return it to the water tank, high pressure water entering the jet hose will pulsate. This creates Harben's "Jump Jet" performance.

The jump jet feature allows operators to jump high pressure hose around radius bends, move nozzles and cutting tools longer distances through difficult-to-climb pipes, penetrate blockages with greater efficiency and free nozzles and cutters trapped by offsets and obstructions.

Because the diversion of high pressure water occurs outside the pump, operators are able to pulsate at pressures up to 2,500 psi without damaging water system components, a common shortcoming of triplex and multiplex pumps.


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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.