MSS SP 154
Low Pressure Knife Gate Valves for Double Block and Bleed
|Publication Date:||1 January 2018|
SCOPE AND FIELD OF APPLICATION
This Standard Practice covers stainless-steel-line
The valves identified in this Standard Practice are intended for use in applications where shock loadings are not encountered. Applications at conditions other than those specified in Section 3 require special design consideration.
The valves identified in this Standard Practice are intended for use in applications where a "Double Block and Bleed" type of isolation is required, and where two individual isolation valves with a removable or drain-containing spool piece between them is typically used.
NOTE: (1) For the purpose of this Standard Practice, "Double Block and Bleed" refers to a valve (or valve application) with two seating surfaces that, in the closed position, provide a seal against pressure from both ends of the valve with a means of venting/bleeding the cavity between the seating surfaces.