Chemical hoses

How to choose a suitable chemical hose?

Before choosing a chemical hose, take the following into account:

• type of medium - i.e. substance transported by the hose, 
• state of matter of the medium - i.e. liquid, gas, 
• concentration and temperature of the substance, 
• working pressure.

The Material Safety Data Sheet is key to the correct choice of hose.  You will get it from the chemical manufacturer or find it online with the right tools.

Also check whether there is a risk of static charge build-up. This is particularly important when working in a hazardous area.

Which chemical hoses for oil-free chemistry and sulphuric acid?

EPDM chemical hose is compatible with basic oil-free substances such as fire-resistant hydraulic fluids, ketone bodies, hot and cold water and alkalis. However, it is not suitable for handling most hydrocarbons, i.e. oils, paraffin, petrol, as well as halogen solvents or different hazardous materials.

EPDM rubber provides very good resistance to heat, ozone, steam and weather conditions. It also withstands sulphuric acid concentrations of up to ~65-70%.

Furthermore, although the raw material is an insulator by nature, thanks to special compounds some EPDM rubber hoses provide electrical conductivity for safety.

Moreover, as it is a rubber hose, oil-free chemistry is not terrible for it (in most cases). Therefore, it will also work well as a hose for the alkalis.

Which chemical hoses for most chemicals and coloured pigments?

UPE hoses made from chemically resistant UHMWPE (Ultra High Molecular Weight Polyethylene) film are suitable for 98% of industrial chemicals. As a cushioning material, UHMWPE is odourless, tasteless, and non-toxic, as well as highly resistant to abrasion.

The inner layer is also ideal for transporting powdered solids. For example, coloured pigments are very fine and harmful. However, the inner layer made of UPE withstands contact with them well and does not cause clogging in the transfer line.

A chemical hose made of UPE will also be suitable for dry tea transfer due to its slippery surface.

Which chemical hoses for oil-based chemicals and petrochemicals?

Fuel and oil hoses are used for transporting petroleum and petrochemical media. Oil-based substances pose a major challenge for rubber hoses.

These hoses meet the required standards for this type of work. They are therefore resistant to contact with petrol, diesel, and oil-blended water.

Which chemical hoses for biological chemicals and natural gas?

Chemical hoses made from synthetic compounds will work for biological chemicals. When you are dealing with, for example, bio-based aromas for odours and flavours, resins, lubricants, natural fertilisers, some industrial and household cleaners, and solvents, as well as drop-in biofuels and others, you need a suitable hose.

Which chemical hoses for caustic chemicals and concentrated acids?

PTFE chemical hoses can be used for the transfer of the most aggressive chemicals, as the inner coating of the hoses is made of PTFE (polytetrafluoroethylene). It can also be made from FEP (fluorinated ethylene propylene).

These types of chemical hoses are resistant to, for example, fuels, solvents, oils, and caustic chemicals.

FEP and PTFE also have other useful properties, such as low friction ratio and lack of chemical reactivity. However, FEP performs slightly better in applications requiring contact with detergents.

In this group, you will primarily find hoses for acids, as well as hoses for paints.

How is a chemical hose built?

Chemical hose is built from 3 layers:

• inner - its main purpose is to ensure resistance to contact with the medium, which is why EPDM or EPM rubber, Viton,, polyamide, polyethylene UPE, or fluoropolymers such as PTFE, PFA, FEP are used for production; 
• middle - i.e. reinforcement (provides mechanical strength and usually takes the form of a fabric braid or, if necessary, a steel wire coil in the case of suction hoses); 
• outer - ensures that the hose is resistant to external factors, which is why it is usually made of a rubber compound.

Almost every chemical hose has a fairly standard construction. The main difference in the types of hose is what materials they are made of.

Remember, also, that any acid or chemical hose needs industrial hose couplings that are corrosion-resistant. These are usually fitted using worm drive clips, screw clamps, or hosetails.