While there are many internationally recognised standard test methods for seals and packings used to seal valve stems in reciprocating or slow, semi-rotary duties, no such standard has been available for continuous rotary applications. However, following an extensive testing and analysis programme, a detailed and robust test procedure is now in place. Compression packing remains a very effective and adaptable method of shaft sealing for many rotary shaft applications in pumps, dryers and specialised rotating equipment. Excellent high-performance products are readily available, but as long as no recognised comparative performance standard exists, there is still the problem of how to identify readily the correct quality of product. Many internationally recognised standard test methods exist for mechanical seals, rotary shaft lip seals, flange gaskets and even compression packings when these are used to seal valve stems in reciprocating or slow, semi-rotary duties, but no such standard is available for their use in continuous rotary applications.
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