The hose, then the shoes or rollers, then the casing lubricant. Everything else - bearings, gearbox, drive - is conventional rotating machinery that never sees the pumped fluid. There are no seals or valves in the fluid path to maintain at all, which is why the parts list is so short.

Its profile changes, so the compression applied to the hose changes. That either under-compresses and costs suction and delivery, or loads the hose unevenly and shortens its life. Because it presents as poor hose life, the shoe is often overlooked while hoses are replaced repeatedly.

More than most operators assume. It cools the hose, so degraded or low lubricant raises hose temperature and cuts life significantly. It is the cheapest single thing that extends hose life, and it is the most commonly neglected item on the whole pump.

Yes, changed rather than topped up. The casing will contain pumped product from the failure, and leaving it in place exposes the new hose to a fluid it may not be compatible with on its outer surface, and can compromise the leak detector. Flushing and refilling is part of a proper hose change.

Yes, as part of routine service. Their entire value lies in working on the day a hose bursts, and a detector that has sat unused for years is an assumption rather than a protection. Testing is quick and it is what makes the containment claim for hazardous duty meaningful.

Because there is no seal in the fluid path - the hose contains the fluid completely, and the rotor shaft never enters it. This is the reason peristaltic pumps are chosen for hazardous and aggressive fluids: the most common leak path on any other pump type simply does not exist.

Hose life falling short of its previous pattern is the key signal. If hoses that used to last a predictable interval start failing early, the cause is usually shoe wear, lubricant condition or increased pressure - not the hoses themselves, and replacing them repeatedly treats the symptom.