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Flexible Pigtails – A Price Worth Paying for Lp Gas Hose

By Kaz Dziamarski, managing director, Clesse (UK) Ltd

Lpg hosing has long been the underestimated link between cylinder and automatic changeover.

Often overlooked, the humble black rubber hose is an essential item in the operation of the regulation system to which it is attached.

We estimate that at least 100,000 pigtail hose assemblies are sold in the UK per year, each made from elastomeric compounds almost exclusively derived from crude oil. Various reinforcement substances are added, such as carbon black, which improves resistance to sunlight; textiles, giving cross-sectional stability of the hose to resist static and dynamic pressures, and plasticisers to maintain flexibility during the lifetime of the product.

One can see that manufacturing the humble pigtail hose compound is a precise art, and this is before you attach the end fittings. Like any oil-based raw material, if there’s one thing for sure, it’s that prices have risen considerably over the last few years.

Have you bought a car tyre recently? It’s probably almost doubled in price in recent years. There is a temptation to buy a cheaper tyre, but we know it won’t do so many miles.

Hoses and tyres are made of similar products, each a complex recipe. However, there is a temptation to substitute expensive commodity ingredients with lower cost substitutes. The product still meets standards but invariably suffers a reduced life.

At Clesse, we select manufacturers that are proven to consistently deliver a hose compound that is reliable and fit for the UK market. This ensures the downstream reliability of our automatic changeovers and regulators and gives customers an acceptable service life in most environmental and installation conditions. Nevertheless, an elastomeric hose will, in time, degrade and require replacement well before the regulator needs changing.

When this replacement is necessary, it’s very much down to the condition and application and not the date on the hose, which was when the hose compound was produced. Final assembly with end fittings can be up to two years later and, with good storage, this has no effect on the quality of the hose produced.

To be precise, the only official application where replacement is required at five years, regardless of conditions, is on lpg cabinet heaters. Otherwise, so long as the hose is in good condition and shows no signs of damage or deterioration, there is no reason why it cannot be used for up to seven years from when it was installed.

For reference, BS 3212 and the UKLPG User Information Sheet 017 – August 2008 give valuable information on hoses and inspection.

By purchasing a good quality hose and taking better care of it, we can help to reduce the 70,000 pigtail hoses (20 tonnes) that end up in landfill sites each year. Alternatively, use a pipe – it’s metallic and flexible and not subject to the same lifecycle constraints as elastomeric pigtail hosing, and consequently has less end of life impact on the environment.

Although stainless steel hoses have been around for some time – some call them 20-year hoses – it’s only recently that their use as a high-pressure cylinder pigtail has gained momentum. To date, there is no specific standard in design, exchange requirements or guarantee of service life in force for lpg applications in the UK, but experience shows this can be equal to the useful life of the regulator or more.

Following requests from customers, the technical team at Clesse in France has designed a new product for the UK in partnership with Witzenmann in Germany. Called Clessinox, it has been sold by Clesse in France for several years and has a manufacturing and design standard of its own monitored by a rigorous NF approval scheme.

The same high standards of design, manufacturing and materials are used for standard UK cylinder connections. Clessinox metallic hoses are made from high quality stainless steel convoluted tubing and braiding and are so flexible that most people think they are rubber!

We believe Clessinox now sets the standard in design, traceable manufacture, maintenance free operation and long term durability for stainless pigtail hosing. Designed and manufactured to BS EN ISO 10380-1, Clessinox also comes from a family of products following new European DIN Norm 14800.

Features include three layer construction – stainless steel convoluted pressure hose with a 12mm internal diameter; braiding with a test pressure of 40bar, full traceability and a batch and manufacturer date, and an outer PVC covering clearly showing that it’s a metallic hose press fitted onto the hose to ensure the whole product is moisture tight and to protect against abrasion.

We currently stock various lengths for new installations or replacement of conventional black rubber hose that are suitable for automatic changeovers, bulkhead regulators or mobile caravan applications to EN1949. No periodic replacement or maintenance is necessary – Clessinox hose has no expiry date.

To summarise, Clessinox has many advantages over existing standard rubber pigtails, both in long term resistance to aging and end of life consequences on the environment, as the product can be recycled with a potential terminal scrap value for the customer. However, this does come at a higher price – approximately three times that of a similar braided rubber hose.

My belief is that, in time, customers given the choice will view this as a price worth paying.

Contact Clesse (UK) Ltd on 01905 842020 www.clesse.co.uk

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