Compressed Air Pumps with PU Membranes

Ever since polyurethane was recognised as an especially wear-resistant material, especially for valve balls in compressed air driven piston membrane pumps a long time ago, Steinle Industriepumpen GmbH has also carried out field tests with membranes made of specially hard wearing polyurethane. The result was surprising: The membranes of pumps, which had been in continuous operation for two years did not show any trace of wear and, in contrast to the previously used membranes, also no signs of material fatigue. These new membranes were unveiled at Ifat and are now used as standard in all pumps. Older pumps can also be retrofitted. However, as the chemical resistance of polyurethane is limited, in cases where sludge contain strong acids or alkalis, the old material Superflex is used. This is a butyl rubber embedded in a thermoplastic matrix. This material is suitable for temperatures up to 100°C, whereas the limit for polyurethane is 70°C.