The weight of the cast-iron piston in this horizontal, wet vacuum pump caused excessive wear of the lower section of the pump cylinder.

The problem was solved by replacing the cast-iron unit with a piston made from Whale brand TUFNOL, fitted with piston rings of the same material. Further modifications included replacing the original gland bush, cross-head bearing bush and steady bearing bush with bushes produced from Bear brand TUFNOL.

After more than eleven years’ service, none of the TUFNOL parts have needed to be replaced. Advantages gained by using TUFNOL components include weight reduction, freedom from corrosion, wear resistance, reduced maintenance time, and greatly increased efficiency of the complete assembly.