Innovative Method to Double Block and Bleed

Double Block and Bleed (DBB) is the preferred approach used to maximize safety while performing piping maintenance. The aim of the paper is to outline an innovative method of achieving DBB on pressurized piping or pipelines. DBB is traditionally achieved by several methods, for example, through using Two Valves, a Valve & a STOPPLE® plugging head, a STOPPLE plugging head & an Isolation Plug or Tandem STOPPLE plugging heads. There are also several DBB methods which utilize inflatable bags or bladders. The STOPPLE Train is a patent pending tool that uses 2 STOPPLE® plugging heads. Only one hot tap is required in the piping for which the STOPPLE Train is inserted. The first STOPPLE plugging head is the trailing plugging head and forms a primary seal. The second STOPPLE plugging head is the leading plugging head and forms a secondary seal. Once sealed, the bleed is accomplished through a relief port allowing downstream maintenance to commence.