A composite hose consists of:
- inner wire helix;
- outer wire helix;
- numerous layers of fabric and foil wound between these two helices.
The entire structure is tight, pressure and vacuum resistant. Both inner helix and inner fabric and foil layers must be chemically resistant to the medium in the hose. The inner hose layer (foil, fabric) is made of the following materials:
- polypropylene (fuel hoses and chemical hoses);
- polyamide (fuel hoses and biodiesel hoses);
- ECTFE (fluoropolymer similar to PTFE, hoses for highly aggressive chemicals);
The inner wire helix is made of the following materials:
- zinc-plated carbon steel (galvanized, G code marking, for fuels);
- aluminium (A code marking, for fuels, very lightweight hoses);
- polypropylene-coated carbon steel (P code marking, for chemicals);
- polyamide – nylon-coated carbon steel (N code marking, for biodiesel, jet fuel);
- AISI 316 stainless steel (S code marking – for chemicals, biodiesel and jet fuel, cryogenic fluids);
Different types of fabrics (polyester, aramid) are used as reinforcement. The outer layer is made of PVC-coated fabric, resistant to abrasion and weather conditions (option – polyamide fabric).
The outer wire helix is made of the following materials:
- zinc-plated carbon steel (galvanized, G code marking);
- polypropylene-coated carbon steel (P code marking);
- AISI 316 stainless steel (S code marking);
Various material configurations can be used to make a given hose type e.g. DANCHEM PG stands for DANCHEM hose with polypropylene-coated inner spiral and outer of zinc-plated steel.
Basically, the composite hoses can be divided into chemical and fuel hoses.
Highly specialized hoses for specific applications are also available e.g.:
- hot oil hoses 100°C;
- hose for biofuels of various kinds;
- hoses for draining water from floating roofs inside storage tanks with petroleum products;
- low-temperature hoses for cryogenic fluids (LPG, carbon dioxide, ammonia, ethylene);
- hoses for liquid sulphur and bitumin;
- lightweight ducting hoses intended for the removal of fumes from tanks and tankers;
- flame retardant version of any standard hose – FIRESAFE.