Energy-absorbing springs for oil and gas industry

The Clifford Spring Company has used Victrex PEEK polymer to develop springs to reduce wear and damage on seals, backup rings and shafts, eliminating the problems inherent with metallic springs

PEEK, the high-performance polymer manufactured by Victrex plc, with its unique combination of high and low temperature resistance, inherent strength, and chemical resistance, has become the material of choice for the manufacture of seal and backup rings in the oil and gas industry.

However, the weakness of seals has always been the necessary addition of the metallic energy absorber, which in extreme circumstances, if the seal wears, can come in contact with and irreparably damage the shaft.

The Clifford Spring Company based in Redditch in the UK, with over 40 years experience in manufacturing energising springs for this sector, has developed a solution to this challenging problem, producing energy-absorbing springs using Victrex PEEK polymer.

"The major benefits of using an energy absorber made with PEEK are that corrosion is eliminated in ferrous-based energy absorbers and the absorber made with Victrex PEEK polymer resists virtually all aggressive chemicals, solvents and lubricants used within the oil and gas industry," said John Clifford, managing director at Clifford Springs: "Further, if the seal should become worn and the energy absorber component is made from the same material as the seal itself, then there will be no damage to the shaft".

An additional benefit of using Victrex PEEK polymer in this application is that the overall weight of the seals is reduced due to the elimination of metallic components, and there are no issues with differing rates of thermal expansion as both the seal and the energy absorber have the same co-efficient of thermal expansion.

The energy absorber spring made with Victrex PEEK polymer can be manufactured as a totally encapsulated item, or as a Garter type spring where the spring made with Victrex PEEK polymer can be added to the seal as a secondary operation, following moulding or machining of the seal.

The total encapsulation method carried out by the seal manufacturer prevents the seal lipping out and therefore prolongs the life of the seal.

A further advantage of having a thermoplastic spring in the Garter type of seal, is that the monofilaments can be produced in virtually any colour in the spectrum, allowing instant identification ensuring the correct energy absorber has been fitted to the seal.

The energy absorbers made with Victrex PEEK polymer are available with an outside body diameter of 1.40mm up to 10.00mm.

The maximum single length that can be produced is 2.4M, this equates to a spring diameter of approximately 750 mm.

Multiple springs can be joined end to end to give a larger spring diameter.

Come and see some of the energy absorbers made with Victrex PEEK polymer, fitted to seals on its stand at Offshore Europe, in Aberdeen 4th-7th September, in the Blue area stand 847.
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