Teflon-lined hoses clean up in food and drink

Edited by the Engineeringtalk editorial team Feb 14, 2008

Thanks to the inherent nonstick properties of Teflon, the hoses are very easy to clean, even when carrying very high-viscosity media.

Fluorflex universal hoses, developed by HSI Schlauch- und Armaturentechnik, Muhlheim/Ruhr, Germany in partnership with Fluortubing, Kerkrade/Netherlands and ContiTech Fluid, Korbach, Germany, are constructed with an inner liner made from DuPont Teflon PTFE 62-N.

This liner is designed in the form of a helically corrugated tube and therefore permits very small bending radii.

As Tobias Sautmann, CEO of HSI, explains: "This enables installation space to be significantly reduced, particularly with large hose diameters (minimum bending radius for DN75 is 200mm)".

"At the same time, this flexibility allows hoses to be fitted in extremely confined spaces, where installation would previously have been impossible".

Teflon PTFE 62-N combines very good flexural fatigue strength and stress crack resistance with high thermal stability and excellent resistance to nearly all media used in food and pharmaceutical production.

This often makes it possible to reduce stock to just one type of hose.

A black conductive strip integrated into the corrugated tube dissipates static electricity.

The tube can also be supplied in an all-white design, eg for the pharmaceutical industry, and with an all-black (fully conductive) inner liner.

The helical geometry not only ensures high flexibility but also gives the transported medium angular momentum that permits higher conveying speeds and up to shorter emptying times.

Thanks to the inherent nonstick properties of Teflon, the hoses are very easy to clean, even when carrying very high-viscosity media.

This - together with the possibility of faster emptying for cleaning or material changes - can achieve significant cost savings in production.

Another advantage for users is the ease with which the Fluorflex hose system can be fabricated on site using safety clamps without the need for laborious de-corrugation in a salt bath, compressing sleeves or purchasing the costly machinery required for this.

Since hose systems can be custom-fabricated quickly in this way, it is usually unnecessary to stock replacement hose lines.

A multiple-ply outer jacket comprising an EPDM intermediate layer, a reinforcing braid made from DuPont Kevlar brand fibres and a covering layer specially tailored for the application protects the Teflon inner liner from damage.

Besides EPDM black, the covering layer can also be supplied in NBR black for contact with oil and gasoline, NBR black high-temperature blend for temperatures above 150C, NBR blue for food applications and EPDM grey for pharmaceutical production.

New products are being developed for transport, chemical engineering and the construction industry.

The whole system is designed for working pressures of 16bar and continuous service temperatures of 150C.

Designs for even higher temperatures are possible.

Fittings can be supplied in many different materials (VA, PP, PVDF, different coatings such as PFA und ECTFE) and with all currently used connections.