ISA75.04, Control Valve Stability

Scope

Describe the forces at work tending to create instability in control valves, including inherent and installed stability. Define design improvements to improve inherent stability. Include general guidelines for improved system design for better stability. Establish degree of stability expected of a specific control valve in a particular application of a given flow control system. Provide terminology and definitions required with the above-stated scope.

Purpose

To describe the nature of instability in control valves. To provide general guidelines through design improvements that improve inherent valve stability. Described differences between inherent and installed valve stability. To combine all these factors into a standard or recommended practice for the user to select the stability level for the application and be able to communicate this to the control valve manufacturer.

A Word from the Chairman

The Recommended Practice ISA-75.18 was withdrawn and replaced by Technical Report ISA-TR75.04.01-1998 (R2006), Control Valve Position Stability. 

For information about upcoming ISA75.04 meetings and other ISA75 and ISA96 meetings, please visit the ISA75 page.

-- Jim Reed

Wael Ahmed Information Member Khalda Petroleum	George Baenteli Voting Member
Gayle Barb Information Member	Eliana Beattie Staff Contact ISA Phone: (919) 990-9228 Fax: (919) 549-8288
Joseph Borge Voting Member Neles Automation Inc Fax: (508) 852-3140	Wayne Caudill Voting Member Arco Products Co Phone: (310) 816-3543 Fax: (310) 816-3501
Anthony Kehoe Information Member Brooks Instruments Phone: (215) 326-3514 Fax: (215) 362-3745	John McCaskill Information Member Expro Group Phone: (713) 983-4953 Fax: (713) 983-4900
James Reed Voting Member Chair Consultant Phone: (281) 379-1610	Paul Schafbuch Voting Member Emerson Process Management - Valve Automation Div Phone: (281) 727-5338 Fax: (281) 727-5389
Ian Verhappen Information Member Industrial Automation Networks Inc Phone: (780) 842-4722 Fax: (780) 628-7352	Warren Weidman Voting Member Managing Director WorleyParsons Phone: (610) 855-3208 Fax: (610) 855-2385
James Young Voting Member The Dow Chemical Company Phone: (979) 238-9703 Fax: (979) 238-0741