Importance

Loading Importance Indicators...

Abstract

A ball valve (10) has a stem (36) and a packing (82) about the stem (36). A spring (85) comprises a plurality of Belleville washers (86) biased between the upper cover plate (72) and the packing (82) for exerting a compressive loading against follower (84) and packing (82) for sealing against the stem (36). The upper plate (72) has an enlarged diameter bore portion (76) adjacent the valve body portion (12) and Belleville washers (86) including a load transmitting ring (88) over the Belleville washers (86) are received within the enlarged diameter bore portion (76). Manual threaded adjusting screws (94) extend through the upper plate (72) and have inner ends in abutting contact with the load transmitting ring (88) to restore a compressive loading thereon if the Belleville washers (86) lose their capability to apply a sufficient compressive loading against the packing (82). The outer ends of the adjusting screws (94) receive a suitable manual adjusting tool such as an allen head wrench for adjustment of the screws (94). A thrust ring (98) is compressed between shoulder (52) on the stem (36) and the upper plate (74) by adjusting nut (100) on the stem (36).

Loading the Abstract Image...

First Claim