Short description
Standard Practice (SP)-81 has been serving the industry for over 46 years; covering all stainless-steel or stainless-steel-lined, cast, or fabricated bonnetless, knife gate valves with flanged ends from size NPS 2 (DN 50) through NPS 36 (DN 900). The valves identified in this Standard Practice are intended for use in applications where shock loadings are not encountered.