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BULLETIN 142APRIL 2002

Soft Seated HUSH Trim - 34699 SOFT SEATED HUSH

®

TRIM

General

The long-standing and high cost problem of leaking control valves in severe duty power and process applications has been solved through the development of a unique soft seat trim design. It is not unusual for generating plants to lose up to 10% of capacity through leakage, often costing from USD The trim is designed for new as well as existing valve installations. Known as the Soft Seated HUSH Trim, the design is unique in that it uses a dual plug, with a primary plug engaging the soft seat and an inner plug engaging the secondary metal seat, thereby preventing throttling at the soft seat. The soft seated trim, when used in conjunction with Copes-Vulcan‘s HUSH Trim, reduces all likelihood of damaging cavitation.
$ 500,000 to
$ 1,000,000 per year. Trimleakage often occurs in severe duty applica- tions such as boiler feed pump recirculation valves. These valves typically are required to remain closed approximately 95% of the time, against shutoff pressures of up to 5000 psig (34450 kPa). Copes-Vulcan‘s Soft Seated HUSH

Field Documentation

Soft Seated HUSH Trims have been operating in boiler feed pump recirculation valves at numerous generating stations since May of 1985. Test apparatus designed at Copes-Vulcan‘s Engineering Center verifies seat tightness, and hence zero leakage.
® Trim cansave money by preventing lost capacity, plus a substantial reduction in maintenance costs. Copes-Vulcan‘s Engineering Center hasdeveloped and tested a patented
1 soft seatedtrim which maintains zero (bubble tight)
2 ® HUSH is a registered trademarkof DeZURIK/Copes-Vulcan 1 leakage throughout the service life of the trim.
Patent Numbers 598859 & 599252 2 Leakage rate equals 0 cc/minute at maximum service differential pressure with water at 60°F (16°C). Inner PlugBalancing CylinderOuter PlugHush Cylinder Strainer Basket(Easy Lift-Out Design) Soft Seat Flow