Positively Isolate Explosive Vapors From Hot Work Areas When Performing Modifications and Repairs

  • 3/4″ to 24″ Pipe Sizes
  • Schedule 40, 80 and STD

EST’s Double Block & Bleed (DBB) Plug revolutionizes isolation and testing of pipe connections. The DBB Plug allows an operator to positively isolate and monitor potentially explosive vapors during “hot work”, then effectively hydrotest the new weld connection with one easy to use tool. The Aluminum/Steel construction makes the tool highly portable, and easy to position. The volume of water required for a test is so small that testing can be accomplished using a hand pump. This greatly facilitates testing in remote areas of the facility.


After determining pipe and schedule size:

  • Install DBB upstream of “hot work” Area.
  • Expand Seals by tightening compression nut(s).
  • Inject inert gas or water between seals (Isolation Zone) and pressurize.
  • Monitor isolation zone and upstream pressure during “hot work”.
  • After Weld cools release pressure and seal, reposition isolation zone over weld area.
  • Pressurize isolation zone (up to 2,250 psi (155.1Bar).



  • Aluminum/Steel Construction: Plug is portable and easy to position.
  • 1.5:1 Safety Factor: Minimum.
  • Reduces NDE.
  • Low Water Requirements: Uses less than a gallon of water, reducing waste/treatment expense.
  • Quality Assurance System: Manufactured under a Quality Assurance Program certified to ISO 9001 and several U.S. nuclear undustry standards including ANSI N45.2, NQA-11, 10CFR 50 Appendix B, and 10CFR 21.