MSS SP 81:2013
MSS SP 81:2013 Stainless-Steel Or Stainless-Steel-Lined, Bonnetless, Knife Gate Valves With Flanged Ends Specifies all stainless steel or stainless steel lined, cast or fabricated bonnetless, flanged knife gate valves in NPS 2 (DN 50) through NPS 36 (DN 900).