Construction projects near natural gas and hazardous liquids pipelines call for extra safety measures to prevent damage that could interrupt service. When an Italian warehouse development company prepared to build a massive logistic centre near Warsaw, Poland, the worksite survey found a 16 in. high pressure gas pipeline running through their construction site. Shutdown wasn’t an option as the pipeline — owned by Polish natural gas transmission system operator Gaz System SA — was connected to nearby housing, providing essential fuel for cooking and heating.
The development company needed to move part of the pipeline before construction, which meant they needed to obtain a permit for working in a hazardous zone and come up with a plan to keep gas flowing throughout construction. To achieve greater efficiency, the development company decided to use just one contractor, choosing T.D. Williamson (TDW) to come up with a turnkey solution to keep the pipeline running at a safe distance from the worksite.
Using one hot tap decreases work time; increases safety
“The most immediate benefit of taking a turnkey approach to the project, with only one provider, is the amount of time we saved in finding a solution,” explains the operation’s project manager. “The other option was to identify several different contractors and try to organise everyone toward this goal.”
TDW began gathering and preparing the documentation for relocating and rebuilding 340 m (1115 ft) of the 16 in. pipeline. Document preparation included obtaining the permits for operating in hazardous conditions, which can be a cumbersome procedure. Then, TDW delivered all materials needed, which included pipe, elbows and fittings.
The pipeline route was close to the edge of the construction site and bordered neighbouring land not owned by the development company. Because of this space constraint, TDW chose to isolate the pipeline using STOPPLE® Train technology. Traditional double block and bleed isolation requires two hot taps, two fittings, and two plugging heads (i.e. more space), while the STOPPLE Train isolation system allows insertion of two isolation seals through just a single opening in the pipeline. This method is ideal for a confined space, faster, and reduces the number of hot taps and fittings required. Plus, it offers an extra layer of safety: if any product escapes past the first seal, it enters a bleed port and is removed from the line.
Isolating the pipeline using the STOPPLE Train system was the most cost-effective method, as it allowed the technicians onsite to work in a limited area without building temporary road crossings or incurring the cost of accessing the land adjacent to the customer’s property. With the pipeline segment safely isolated, TDW added a tie-in line to facilitate rerouting the pipeline product to the end user during construction. The tie-in was 360 m (1181 ft) of high pressure 6 in. temporary pipeline, built onsite.
After the high-pressure pipeline was relocated, the isolation system was removed and the STOPPLE Plus fitting and tapped opening were fitted with a LOCK-O-RING® PLUS completion plug, creating a pressure-tight seal. The pipeline relocation was completed, including the disassembly of 460 m (1509 ft) of the 16 in. pipeline that was no longer needed.
The warehouse development company had successfully managed a potential safety issue on their construction site without interrupting gas service to nearby housing. Plus, they saved time and cost by using a turnkey solution.
Edited from source by Stephanie Roker
Read the article online at: https://www.worldpipelines.com/equipment-and-safety/08092016/tdw-turnkey-solution-used-on-gas-pipeline-project/