Composite hose explained: films, wires and the fittings that thread into them

Composite hose is the one industrial hose that is not a rubber hose with something added. It has no bonded wall at all — just layers of film and fabric wrapped between two steel or aluminium wires and sealed into the fittings at each end. That construction is why it is light, why its liner can be matched to the product, and why its fittings are a different part from everything else on the shelf.

/01How it is built.

An internal wire helix sits in the bore and gives the hose its shape and suction strength. Over it go layers of polymer film — polypropylene, polyethylene, polyester and, in the PTFE grade, a PTFE lining — and layers of fabric for strength. An external wire helix wound between the internal turns clamps the whole stack together, and a weatherproof PVC cover finishes it. Because nothing is vulcanised, the films can be selected for the product being carried.

/02Why it is used.

Two properties matter on a transfer job. It is lighter than a rubber hose of the same bore, which counts on hoses handled by people at a tanker, a rail car or a ship's manifold rather than by a crane. And it tends to weep before it fails: a damaged layer leaks slowly instead of letting go suddenly, which on flammable or aggressive transfer is worth a great deal. The vapour recovery grade adds an internal aluminium wire and polypropylene layers for returning fuel vapour to a tank.

/03Fittings that thread into the wire.

A rubber hose is gripped by squeezing its wall onto a barb. Composite hose has no wall to squeeze, so its fittings engage the wire instead: a spiral tail is threaded into the hose along the internal helix, and a ferrule or a lug nut on a female liner clamps the films and the outer wire down onto it. Our composite fittings — cam lock C and E with spiral tails, SS female liners with lug nuts, hex male tails with BSP or BSPT threads and a flanged tail to ASME B16.5 — are made for composite hose; Sunpool publishes no working pressure for the fittings themselves, so the assembly is rated with the hose. Stainless versions are supplied with 3.1 certificates and leak-tested.

/04Handling and storage.

The trade-off is toughness. Composite is less tolerant of being crushed, dragged over a quay edge or driven over than a rubber hose of the same bore. Support it on saddles where it crosses an edge, keep it off sharp ground, store it straight or on a reel rather than kinked, and inspect the outer wire and cover for crushing after every job. A kink or a crushed section is a reason to retire the length.