From the fluid. Natural rubber for abrasive slurries thanks to its abrasion resistance and recovery, nitrile for oils and fats, EPDM for many acids, alkalis and ketones but not hydrocarbons, and chlorosulphonated polyethylene for strongly oxidising chemicals. Food and pharmaceutical work adds compliance requirements on top.

Reinforced hose has fabric reinforcement layers and a precisely machined wall, and is what industrial shoe pumps use to withstand pressure. Thin-wall tube in silicone, PVC or fluoropolymer is used in laboratory and light dosing pumps with roller heads, where accuracy and cleanliness matter more than pressure capability.

Because compression is set by the fixed gap between shoe and casing. A hose with too thin a wall will not be squeezed fully closed and the pump loses suction and delivery; too thick and it is over-compressed, which generates heat and destroys it early. The wall must match the pump specification exactly.

For any metering or dosing duty, yes. A new hose recovers more fully than the one it replaced, so the volume displaced per revolution changes slightly. Assuming the calibration carries over is a common source of dosing error immediately after a hose change.

Number of compressions above all, then pressure, temperature, and the chemical and abrasive nature of the fluid. Running the pump slower extends life substantially. Manufacturers publish expected life under stated conditions, which is realistic enough to plan replacement intervals around.

Only if the bore, wall thickness and construction match the pump's requirement precisely, and many are not interchangeable despite appearing similar in size and material. An incorrect wall thickness is the usual problem, and it either loses performance immediately because the hose never closes fully, or shortens life dramatically because it is over-compressed on every revolution.

Hoses for these duties must meet the relevant food-contact or pharmaceutical regulations for the jurisdiction, with documentation, in addition to being chemically compatible. Compliance and chemical resistance are separate requirements and both have to be satisfied - a compliant material that the product attacks is no use.