STATS Group were recently retained by a major operator in Australia to provide isolation of a pressurised 10” LPG pipeline at a natural gas plant in Victoria. The isolation was required to allow a launcher valve to be safely replaced while the system remained live and at an operating pressure of 41 bar.
It was the first time STATS Group has deployed their hot tap installed BISEP® on an Australian project. The BISEP provides a fail-safe, fully proven double block and bleed (DBB) isolation and was deployed through a welded split tee fitting, without the need for additional hot taps to bleed or vent.
The BISEP isolation is provided by a spherical dual seal plug, deployed from a pressure competent launcher through a slab valve and rotated towards the pressure threat. After performing validation tests on the BISEP, STATS technicians confirmed successful double block isolation and an isolation certificate was issued to the client. Nitrogen was then flushed through the BISEP launcher to purge the system and create safe worksite conditions to allow removal of the launcher valve. Once the new valve had been fitted nitrogen was again used to perform a joint re-instatement leak test of the newly installed valve against the back of the set BISEP.
After a successful leak test of the reinstated valve the pipeline pressure was equalised, the BISEP was then unset and recovered into its launcher. The slab valve was then closed, allowing the BISEP launcher to be depressurised and removed. STATS supplied personnel and equipment which included split tee fittings, hot tapping machine, DBB slab valve, BISEP and completion plugs. All hot tapping and line isolation work was carried out by STATS technicians.
Gareth Campbell, STATS Regional Sales Manager for South East Asia, said: “This project marks a significant milestone for STATS. This is the first time that our BISEP has been deployed in Australia and we are encouraged by the level of interest shown in the region to adopt this game-changing technology. The BISEP® offers significant safety advantages over traditional line stop technology. The hydraulically activated dual seals provide leak-tight isolation of live, pressurised pipelines.
“By using the BISEP operators can make significant savings by performing maintenance or repair work without the need for a shutdown. The single-entry point of the BISEP reduces costs and operational timescales by providing a verified double block and bleed isolation through a single intervention point, without the need for additional hot tapped bleed ports.”