A rotor carrying shoes or rollers compresses a hose against the casing. As it turns, the compressed point travels along the hose, pushing the contents ahead of it, while the hose recovers behind the shoe and draws fresh fluid in. Each revolution displaces a fixed volume.

Because the fluid only ever touches the hose bore. There are no seals, valves, or wetted bearings for grit to score or acid to attack, so the chemical and abrasion problem reduces to one question: which hose material resists this fluid. That is far easier to solve than protecting a whole pump.

Yes, indefinitely and without damage, which distinguishes it from almost every other pump type. There is nothing that depends on the fluid for lubrication or cooling in the wetted path, so loss of suction is an inconvenience rather than a failure - a genuine advantage on intermittent or batch duty.

No - it pulses, because compression is intermittent as each shoe engages and releases. Where smooth delivery matters, a pulsation damper is fitted downstream, and multiple-shoe designs reduce but do not eliminate the effect. This is the format's main hydraulic disadvantage.

It is, and widely used for exactly that. Each revolution displaces a fixed volume, so flow is proportional to speed and metering follows directly from motor control with no separate measuring element. Accuracy degrades as the hose ages and loses recovery, so calibration should be repeated after a hose change.

The hose, in both cases. Maximum discharge pressure is what the hose will withstand under repeated compression, and temperature limits follow the hose material's rating. Neither is set by the pump body, which is why hose selection is effectively pump selection for this family.

It depends on the fluid, pressure, speed and hose material, but life is predictable enough to schedule rather than await. Manufacturers publish expected life under stated conditions, and running slower extends it substantially - which is why oversizing the pump and running it slowly is a common and effective strategy.

It bursts, and the contents are released into the pump casing rather than to atmosphere. On industrial pumps the casing is filled with lubricant and a leak detector senses the change, so the failure is contained and detected. That containment is why the format is accepted for hazardous fluids.

Fully - reversing rotation reverses flow, with no valves to reseat and no priming to re-establish. That makes it useful for clearing blocked lines, draining back to a tank and recovering product, and it is one of the practical conveniences that keeps the format popular in batch processes.

At high pressure, at high temperature, at very high flow rates, and where pulsation cannot be tolerated and a damper is impractical. It also has a running cost that other pumps do not - the hose - so on clean, benign fluid a centrifugal or gear pump will usually be cheaper to own.