Which hose is suitable for transporting aggressive chemicals?

A food hose must demonstrably comply with standards for materials that come into contact with food; a standard water hose is not subject to these requirements. The main standards are European Regulation (EC) No 1935/2004 and the US FDA regulation 21 CFR 177.2600. The standards a hose complies with are stated on its datasheet.

The difference lies mainly in the inner lining. In a food hose, the lining is free of harmful substances and carbon black, and it does not impart any taste or odour to the product. The reinforcement must not affect the product either: rusting of the helix must be ruled out. Foodstuffs include not only milk and juices, but also edible oils, fats, beer and wine.

With water, the question is also what kind of water is involved. Drinking water has its own standards, while industrial or surface water sets different requirements. An example of a food hose is the LIQFOOD-16-SD: an NBR suction and discharge hose with a white, smooth inner lining that complies with FDA and EU 1935/2004, suitable for milk, vegetable oils, fruit juices, beer, wine and alcohol up to 92%, among others. View all food hoses.

You choose an abrasion-resistant (wear-resistant) hose as soon as you transport abrasive media, such as blasting grit or catalyst granules. A standard industrial hose does not really exist: the choice always depends on the medium. A chemical hose with an EPDM or UHMWPE lining, for example, is not designed for abrasive media.

For abrasive applications, an inner lining of natural rubber (NR), SBR or polyurethane (PU) is suitable. An example from the petrochemical industry is dry catalyst, such as FCC catalyst based on zeolites and aluminium oxide. It is conveyed as hard granules or powder and requires a highly wear-resistant hose.

Also consider the outer cover. Hoses that are dragged across the ground in practice also wear on the outside. The NARCORFLEX® ABRADURA was therefore developed together with an industrial cleaning company and has both a wear-resistant lining and a wear-resistant cover. In addition, the lining stays smooth even in a bend, so abrasive media cannot wear through folds. This significantly extends the service life. View all abrasion and wear-resistant hoses.

For high-pressure steam, use a dedicated steam hose with steel wire reinforcement, such as the FLEXCITED® FLOWINTUBE® VAPORTOR-18-D. This hose is manufactured to EN ISO 6134 Type 2/A and is suitable for saturated steam up to 18 bar working pressure, with a continuous steam temperature of up to 210 °C and a short-term peak temperature of up to 232 °C. The burst pressure is 180 bar. A standard water hose is not designed for this: steam combines high pressure with high temperature, and contact with escaping steam causes severe burns.

The difference between saturated and superheated steam is important here. Saturated steam is water vapour at exactly the boiling temperature corresponding to its pressure; it sits on the boundary between evaporation and condensation. At 1 bar this is approximately 120 °C, at 18 bar approximately 210 °C. Superheated steam has a higher temperature than the saturation temperature at the same pressure and degrades rubber considerably faster. An EPDM steam hose such as the VAPORTOR is therefore designed for saturated steam within the specified operating limits.

Only use suitable high-pressure steam couplings and allow the hose to cool down and drain while depressurised after use. Also view the full range of steam hoses.

A lay-flat hose is the better choice when you only need to discharge and storage space matters. Because a lay-flat hose has no helix, it rolls up flat and takes up much less space than a round hose. That is why this type is widely used on ships, for example for transferring oil and fuels.

A lay-flat hose is not suitable for suction: under negative pressure the hose collapses. You can see this in hose designations: D stands for discharge, SD for suction and discharge. Also consider situations in which a vacuum can occur, for example when a bunker hose hangs high in a boom and a valve is closed after disconnection. For that application, a suction and discharge hose with a helix, such as the FLOWINFLEX® OILREXTOR, is the better choice; a lay-flat hose performs best as a transfer hose.

The FLOWINFLAT® PROBUNKER has a working pressure of 20 bar and a burst pressure of 60 bar, and is suitable for oil and fuels in applications including rig supply, ship-to-ship and ship-to-shore transfer, tank trucks and storage tanks.