Full Description

This Standard Practice covers dimensions, design, testing, and marking requirements for butterfly
valves. Further reference should be made to the MSS SP-68.

This Standard Practice covers two types of butterfly valves:
Type I - Valves for tight shut-off
(Tested per Section 10.2.1)
Type II - Valves permitting seat leakage
(See Section 10.2.2)
This Standard Practice covers flanged-end, single-flange (lug-type), and flangeless (wafer-type) valves in size NPS 1¿ through NPS 72, along with grooved-end valves, and shouldered-end valves, with pressure ratings in accordance with the requirements of Sections 3 and 4.