Peristaltic Pumps

The Hose Does All the Work

Inside the pump head, a rotor carries two or more rollers or shoes. As the rotor turns, each one presses the hose flat against the housing and rolls along it. The liquid trapped ahead of the squeeze is pushed out. Behind it, the hose springs back and draws in fresh liquid.

That simple action gives some rare strengths:

• No contamination: only the hose touches the fluid, so there is no seal to leak.
• Accurate dosing: flow is directly tied to speed.
• Self-priming: the pump primes itself and can run dry without harm.
• Reversible: it can run backwards to clear a line.
• Handles abrasives: slurry and solids cause little wear, because nothing slides against the fluid.
• Gentle: squeezing protects shear-sensitive liquids such as cultures, latex and some food products.

Hose Pumps or Tube Pumps?

Industrial Hose Pumps

These use heavy reinforced hoses and sliding shoes, with the pump head part filled with lubricant to cool the hose and cut friction. Many industrial hose pumps handle pressures up to about 15 bar and move large volumes of slurry, sludge and grout. They suit mining, wastewater, construction and chemical duties.

Tube Pumps

Tube pumps use lighter, unreinforced tubing pressed by rollers, and they run dry with no lubricant. They work at low pressure and suit precise dosing in water treatment, laboratories and food plants. Changing the tube takes minutes.

Choosing the Right Hose

The hose is the heart of the pump, so match it to the fluid first:

• Natural rubber: the best choice for abrasive slurries and many dilute acids.
• NBR (nitrile): oils, greases and fatty food products.
• EPDM: stronger acids, alkalis and many chemicals, but not oils.
• Food grade rubber: dairy, beverages and other food products.
• Silicone or thermoplastic tubing: dosing, lab and hygienic duties on tube pumps.

Check the temperature as well as the chemistry. A hose rated for a chemical at 20°C may soften quickly at 60°C.

Speed: The Biggest Lever on Hose Life

Hose life falls sharply as speed rises. Every turn of the rotor flexes the hose once more, and heat builds with each squeeze. A few simple rules help:

• Size up and slow down. Choose a larger pump running slowly over a small pump running flat out. The purchase price is higher, but hose costs fall for years.
• Go slower for abrasive slurry and hot fluids.
• Fit a variable speed drive, so the pump only runs as fast as the process needs.
• Run continuous duties more slowly than duties that stop and start.

As a rough guide, halving the speed can more than double hose life on many pumps.

Changing a Hose, Step by Step

On most industrial hose pumps, the job looks like this:

1. Stop the pump, isolate it and drain the lubricant.
2. Remove the inlet and outlet flanges and their clamps.
3. Jog the rotor with the drive to push the old hose out.
4. Clean the pump head and check the shoes for wear.
5. Lubricate the new hose and jog it into place.
6. Refit the flanges, refill the lubricant and restart.

Always use the lubricant the maker specifies, because the wrong type can attack the hose rubber.

Peristaltic Pumps Specifications to Check

• Flow at your required discharge pressure
• Hose or tube bore, material and wall thickness
• Maximum speed for continuous running
• Suction lift and inlet conditions
• Fluid type, temperature, solids content and abrasiveness
• Drive: fixed speed motor, gearbox or variable speed drive
• Port size and connection type

Signs It Is Time for a New Hose

• Flow falls at the same speed, because the worn hose no longer springs back fully.
• The pump head runs hotter than usual.
• The lubricant looks dark or contains the pumped fluid.
• A leak detector in the pump head trips, which usually means the hose has burst.

Many sites change hoses on a fixed-hour schedule. That is far cheaper than cleaning up after a burst inside the pump head.

Where Peristaltic Pumps Work

• Thickener underflow and tailings slurry on mine sites
• Lime, ferric and polymer dosing in water and sewage treatment
• Fruit pulp, yoghurt and sauces in food plants
• Paints, inks and aggressive chemicals
• Grout and concrete additives on construction jobs
• Filter press feed and sludge transfer

Peristaltic or Another Pump?

For thick sludge at high flow and steady pressure, progressive cavity pumps often cost less to run. If you need a portable pump that runs on compressed air, diaphragm pumps are worth a look. For hygienic transfer of thick food products in larger volumes, lobe pumps are a common alternative. Our lifecycle support team can also help you set hose change intervals that suit your duty.

What to Send Us

Send the pump model and the hose part number, which is usually printed along the hose itself. Tell us the fluid, its temperature and any solids, plus the speed the pump normally runs at. If hoses are failing early, tell us how many hours they last, because that tells us a lot.