Composite hose assemblies
Composite hose assemblies – general information
Composite hoses are lightweight and highly flexible hoses with a special multi-layered construction. They consist of multiple layers of plastic film or fabric, spirally wound in the form of strips between two wire spirals: an inner and an outer spiral. Depending on the material of plastic (polypropylene, polyamide, ECTFE) and wire (galvanised steel, stainless steel, aluminium, polypropylene-coated steel) used, they are designed for the transport of chemicals (also aggressive), petroleum products, liquefied gas, concentrated alcohols, etc. They are mainly used for unloading and loading of tank cars, railways and in maritime transport (ship-to-shore and ship-to-ship), as well as in industrial installations. The hoses are supplied in the form of ready-made, pressure-tested hoses, terminated with a variety of end fittings and couplings. Composite reloading hoses are often fitted to filling and emptying (UNO) equipment in land and port handling terminals. In Poland, reloading hoses are subject to the requirements of the Transport Technical Supervision and are supplied with the relevant TDT certificates.
All composite hoses supplied by Tubes International are pressure tested and checked for electrical conductivity. In many cases it is possible to repair the hose by reinstalling the end. Replacement should be carried out by the supplier, Tubes International.
Hoses suitable for petroleum and chemical substances to a certain extent can also be found in other chapters of the INDUSTRIAL HOSES section, particularly: fuel, oil and petroleum hoses, chemical hoses, PTFE hoses, pressure metal hoses, ducting and ventilation hoses.
Composite hoses have a specific, complex construction, completely different from that of conventional hoses (e.g. rubber, steel hoses). The inner spiral provides the vacuum strength of the hose. Superimposed layers of fabric and foil seal and reinforce the hose and are a combination of different materials depending on the version. This solution provides high pressure, chemical and thermal resistance as well as flexibility. The correct choice of these materials ensures chemical, temperature and pressure resistance. The outer spiral binds all the components together, giving resistance to abrasion and mechanical trauma.
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Due to their specific construction and complex crimping technology, composite hoses are only supplied in the form of prefabricated hoses, terminated with various end fittings (internal threads, external threads, flanges, tank connectors, TW connectors, CAMLOCK connectors, etc.). For very aggressive chemicals, stainless steel ends coated with ECTFE (a fluorine polymer similar to Teflon) are used. There is a special fire-resistant version of FIRESAFE hose – contact Tubes International.
Composite hoses are designed and manufactured to high standards and comply with various international and US standards. Among these are:
- EN 13765:2018 specifies a number of requirements for thermoplastic (non-vulcanised) multilayer hoses and hoses for the transfer of hydrocarbons, solvents and chemicals, including: internal diameter, maximum operating pressure, minimum bend radius, operating temperature range, electrical properties, etc. Type 1 hoses are suitable for vapour applications, while Type 2, 3 and 4 hoses are used for liquid media.
- IGC Code – (an extension of this abbreviation is the International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk) – is the International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk. These regulations were adopted in 1983 by the IMO (International Maritime Organisation). Heavy-duty hoses for ocean-going vessels can be approved in accordance with the IMO Code, BCH and IBC requirements.
- IBC Code – an international standard that contains requirements for the carriage of hazardous chemicals and noxious liquid substances in bulk by sea.
- USCG (United States Coast Guard) – for maritime applications, the federal agency responsible for maritime safety and environmental protection in ports and seaways.
- AS 2683-2000 – This Australian Standard specifies requirements for hoses and hose assemblies for the transfer of crude oil and petroleum products (excluding liquefied petroleum gas), at product temperatures up to +65°C and ambient temperatures between -20°C and +55°C.
When selecting materials in terms of chemical resistance (materials that are in direct contact with the medium to be transferred), it is important to consider both the material of the inner layer of the hose and the inner spiral. It is also important to consider the corrosive effect of the external environment, e.g. hydrochloric acid vapour, it is then important to consider the resistance of the materials of the coating and the outer spiral.
| index marks | inner spiral material | outer spiral material |
|---|---|---|
| GG | galvanised steel | galvanised steel |
| AG | aluminium | galvanised steel |
| AA | aluminium | aluminium |
| PG | polypropylene-coated steel | galvanised steel |
| NG | nylon-coated steel | galvanised steel |
| SG | AISI 316 steel | galvanised steel |
| PS | polypropylene-coated steel | AISI 316 steel |
| SS | AISI 316 steel | AISI 316 steel |
| PP | polypropylene-coated steel | polypropylene-coated steel |
| fabric and foil material |
| polipropylene |
| polyamide |
| PTFE |
| ETFE (ECTFE) |
| polyester |
| aramid fibre |
| glass fibre |
Due to the increasing use of biofuels, the problem of the correct choice of hose for this application is very important. In particular, biodiesel contains components such as vegetable oil esters, which have a damaging effect on elastomers and plastics used for hoses and seals (nitrile, polypropylene, PVC and others). Also, some metallic materials used in the manufacture of end fittings and equipment adversely affect the properties of fuels. Brass, bronze, copper, lead, tin and zinc can accelerate fuel oxidation processes and form insoluble deposits or gels when reacting with fuel components. Therefore, the use of copper alloyed, brazed or zinc coated terminals should be avoided. Instead, the use of fittings and equipment made of aluminium, stainless steel or non-galvanised carbon steel is recommended. DANOIL9 and AEROSTAR hose is recommended for biofuel applications.
Electrical conductivity is ensured by contact between the inner spiral and the outer spiral and the end (direct, via a collet, anti-electrostatic cable and conductive rubber gasket). The resistance between the hose ends according to EN 13765:2018 does not exceed 1 Ω/m (2.5 Ω/m for DN <50). For liquefied gas hoses according to EN 13766:2003 not more than 10 Ω.
The operating pressures given in the tables are the maximum permissible operating pressures. The safety factor is 4:1 at +20°C (HEAVY DUTY, CRYOGENIC: 5:1). The higher the operating temperature, the lower the operating pressure. The use of hoses for temperatures above +60°C requires confirmation. The use of hoses at extremes of pressure, temperature and bend radius is not recommended. The correct and final choice of hose for a particular application should always be confirmed in writing by Tubes International.
All types of composite hoses can be made in the FIRESAFE flame-retardant version. It has additional heat-reflective and flame-retardant layers to ensure that the hose maintains its integrity and continuity of flow for a defined period of time, allowing emergency action to be taken. In tests, FIRESAFE hose filled with aviation fuel maintained its integrity in flames at +800°C for more than 30 minutes and did not sustain burning even at +1200°C. In addition, the loss of leakage occurs gradually through the hose wall after time has elapsed, with no sudden rupture or discharge, allowing for firefighting and rescue operations.
List of products:
Composite fuel hoses
Composite biofuel hoses
Composite fuel lines for tankers
Chemical composite hoses
Composite hoses for cryogenic liquids
LPG composite hoses
Composite hoses for high temperatures
up to +160oC
Composite hose bun
made of polyuretan
Protecion rings
in NBR, EPDM rubber or silicone
Composite hose trolley
