Restricted-Area Sealing Means Or Restricted-Area Pack-Off
Pack-off or other device used to isolate an area at higher pressure from one at lower pressure. NOTE This device serves to limit pressure-induced loads on connectors or areas of a lower pressure rating. It may also be a seal that encloses a pressure-containment area smaller than the adjacent ring gasket or connector seal.
Source: API SPEC 6A, Specification for Wellhead and Christmas Tree Equipment, Twentieth Edition, October 2010 (Addendum November 2012). Global Standards