Subsea BISEP Line Plugging

The BISEP® provides the highest level of hot tap installed pipeline isolation in the industry. Complying with all relevant subsea isolation guidelines, the BISEP ensures safe worksite conditions for divers and the environment from breaking of containment to reinstatement.

8in Subsea BISEP deployment

The BISEP is the only hot tap installed double block isolation tool that satisfies the design criteria for DNV Type Approval for Pipeline Isolation Plugs. The design criteria satisfies the requirements for Pipeline Isolation Plugs to provide dual seal and isolation in accordance with Offshore Standards: DNV-OS-F101 (Submarine Pipeline Systems) and recommended Practices: DNV-RP-F113 (Subsea Pipeline Repair) and is code compliant with: ASME BPVC Section VIII, Division 2.

The use of the BISEP provides a high integrity, temporary subsea isolation that offers operators significant benefits by avoiding the need to decommission and then recommission the entire subsea infrastructure.

BISEP Hot Tapping & Plugging
BISEP Subsea Line Stopping Tool
Subsea BISEP and Bypass
14in Subsea BISEP



3”– 56”


up to 153 bar / 2220 psi


DNV Type Approval


-20°C to 100°C


  • Subsea Isolation Valve installation, replacement / repair
  • Pipeline tie-in / re-routing
  • Sectional pipeline replacement / repair
  • Riser replacement / repair
  • Pressure testing, leak detection of risers or repaired pipelines
  • Isolation of subsea manifolds or skids for repair or replacement
  • Dead leg removal
  • Platform / pipeline abandonment, bypass, or decommissioning

Key Features

  • Double block and bleed isolation compliant with subsea industry isolation best practice. (DNV-RP-F113 Pipeline Subsea Repair – recommended practice)
  • Monitored dual seal annulus void proves seal integrity before and during intervention work
  • Isolation integrity continuously monitored through annulus void, hydraulic set circuit and body vents
  • Seal annulus void provides a Zero-Energy Zone (minimal volume x pressure)
  • In bad weather, enhanced actuation system allows long-term disconnection from support vessel
  • Isolation remains stable and leak-tight even with significantly fluctuating pipeline pressures
  • The BISEP design ensures diver safety in the event of negative and positive pipeline differential pressures
  • Plugging head designed to take pressure in the reverse direction. This allows pressure higher than the isolated pipeline pressure to be applied to the reinstated pipework (as a pressure test or purge) prior to removing the BISEP.

Related Resources


Temporary Line Plugging
14in Subsea Pipeline Isolation and Repair, East China Sea

14in Subsea Pipeline Isolation and Repair, East China Sea

Play Video
Subsea Repair Scenarios of Damaged Pipelines

Subsea Repair Scenarios of Damaged Pipelines

Pressurised pipeline repair facilitated by non-piggable and piggable type approved isolation tools
Access Webinar

28" Subsea Pipeline Isolation & Repair, Yacheng Pipeline, China

STATS Group were contracted by COOEC Subsea Technology Co Ltd to provide temporary subsea isolation of the Yacheng pipeline, situated in the South China Sea. The 780 ...
Read the Case Study

8" Subsea Pipeline Isolation And Repair

Play Video
Emergency Pipeline Repair Isolation Systems

Emergency Pipeline Repair Isolation Systems

An assessment of temporary pipeline isolation devices used to facilitate safe maintenance of pressurised pipework or systems
Access Paper

10" Subsea Hot Tapping and Plugging, Gulf of Mexico

STATS Group was contracted to assist with the isolation and abandonment of a 10” oil pipeline in the Gulf of Mexico, at a water depth of approximately 25 meters. The ...
Read the Case Study

Contact Us

We offer expertise and cutting-edge technologies to solve your integrity challenges.

Terms & Conditions

Click on the links below to download a copy of our Terms and Conditions

Purchase Order Terms and Conditions

Terms and Conditions for Sale, Rental, and Services

For further information, please email: