Douglas A Gray

US Patent:

6681790, Jan 27, 2004

Filed:

May 28, 2002

Appl. No.:

10/156529

Inventors:

Bruce P. Knobbe - Tomball TX
Douglas S. Gray - Lancaster PA

Assignee:

ITT Manufacturing Enterprises, Inc. - Wilmington DE

International Classification:

F16K 300

US Classification:

137 1501, 251326

Abstract:

A ported slide gate valve having a gate for regulating the flow of a fluid through the valve, a seat located in the valve interior, and a means for causing the gate to move in such a manner that the gate fractures any scale built up in the lower portion of the valve interior, prior to the gates movement to a valve closed position. The scale is fractured in a direction away from the seat and deposited in the fluid. More particularly, the means for causing the gate to move includes a primary piston and a secondary piston, where the primary piston is coupled to the gate. In the valve closed position, the secondary piston holds the primary piston in the desired position. A movement of the secondary piston causes the gate to move to fracture the scale in the lower portion of the valve interior.