摘要 |
A packing containment assembly for sealing an operating member such as a shaft or stem in a fluid control valve, particularly where PTFE packing is used. A pair of zero clearance anti-extrusion rings of PEEK material are mounted in the shaft with the PTFE packing therebetween. Each ring has an inner diameter slightly less than the shaft outer diameter to form an interference fit. The rings are split with a scarf cut to provide an overlapping joint and enable mounting of the rings on the operating member. A male adapter PEEK ring matches a V-type female packing ring which significantly reduces the amount of PTFE packing needed for a reliable seal. A step cut PEEK zero clearance anti-extrusion ring could be used as well as a fractured carbon ring.
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