API STD 609-1991
Lug- and Wafer-Type Butterfly Valves (Fourth Edition)

Standard No.

API STD 609-1991

Release Date

1991

Published By

API - American Petroleum Institute

Status

Be replaced 2004-06

Replace By

API STD 609-1997

Latest

API STD 609-2021

API STD 609-1991 history

• 1970 API STD 609-2021
• 2016 API STD 609-2016 Butterfly Valves: Double-flanged@ Lug-and Wafer-type (Eighth Edition)
• 2009 API STD 609-2009 Butterfly Valves: Double-flanged@ Lug- and Wafer-type (Seventh Edition)
• 2004 API STD 609-2004 Butterfly Valves: Double Flanged@ Lug- and Wafer-Type (Sixth Edition)
• 1997 API STD 609-1997 Butterfly Valves: Double Flanged@ Lug- and Wafer-Type (Fifth Edition)
• 1991 API STD 609-1991 Lug- and Wafer-Type Butterfly Valves (Fourth Edition)