To help a customer isolate a section of a gas pipeline being upgraded and replaced, TDW employed three new applications of its technology, along with the first use of ZEVAC® cross-compression equipment.
Isolating the Lines
TDW ProStopp® DS Isolation Tool
An East Coast gas company needed to replace a section of bare steel pipe as part of their infrastructure upgrade program. They were also installing a new gas regulator station on the same project. The 3,200 foot section of 16” and 10” pipeline, needed to be replaced without shutting off service to any customers.
TDW recommended the use of Spherical 3-WAY Tees at both locations. With Stops set thru the Spherical Tees, the line could be isolated while gas was still allowed to travel thru the system thru the new permanent bypass that was welded between the outlet of the two spherical tees.
To isolate the section of pipe, TDW technicians deployed a 16” STOPPLE® Train, a patented system designed to isolate sections of pipeline for maintenance or repairs while the line remains in service. The STOPPLE® Train Isolation Machine uses double block and bleed technology, featuring two Sealing Cups with a bleed port between to ensure secure isolation.
For isolating the 10-inch line, TDW deployed the 10-inch ProStopp® DS Isolation Tool, which also uses double block and bleed technology with two hydraulically activated plugging heads.
Redirecting Gas Instead of Venting
Once the isolations were set on the 16-inch and 10-inch lines, the trapped gas between the isolated sections needed to be removed so that the line could be cut and capped. Rather than venting the gas into the atmosphere the traditional method, TDW technicians utilized a ZEVAC® (Zero Emission Vacuum and Compressor) Quad to extract the gas from the isolated section and redirect it back into the existing 16-inch line.
Gas utilities implement cross-compression technology like ZEVAC for methane emissions reduction during live gas operations.
ZEVAC® extracts gas from the isolated section and redirects it into the 16-inch line.
After depressurizing the line, the team secured the area overnight. Upon returning, they verified that the isolation seals were intact, providing a 100% shut-off. With no gas remaining, the utility safely cut out the old section and welded end caps. This permanently rerouted gas thru the spherical tees and into the new section of pipe.
Conditioning the Line
TDW TOR 3-WAY Tee Bypass
Another TDW first on this project, TDW’s new 2-inch THREAD-O-RING™ (TOR) 3-WAY™ Tee was used to build a bypass line between the new and old pipelines. The utility did this two weeks before the isolation, when they were conditioning (pickling) the line. Once the STOPPLE and the ProStopp were set, the TOR 3-WAY Tee Bypass was employed as the suction and discharge point for the ZEVAC® machine during line conditioning.
When the bypass was no longer needed, the TOR 3-Way™ Tee was isolated using TDW’s new Temporary Isolation Plug (TIP). Used for the first time on site, the TIP allowed the utility to safely decommission the outlet on the TOR 3-Way Tee. After both lines were capped off, the TOR Plugs were set in the TOR fittings, enabling the utility to complete the fittings.
Results
This complex isolation project was completed on schedule, allowing the utility to safely install the sections of pipeline without shutting off service to any customers. The new TDW technologies utilized in this project included:
TDW 10-inch ProStopp® DS Isolation Tool
TDW 2-inch THREAD-O-RING™ (TOR) 3-WAY™ Tee
TDW Temporary Isolation Plug (TIP)
Additionally, TDW technicians effectively operated a ZEVAC® Quad cross-compression unit to redirect about 25,000 scf of gas back into the 16-inch line, effectively reducing the utility’s methane emissions. The collaboration between TDW’s isolation tools and ZEVAC® marked a successful first use of these combined technologies.
Our application specialists at Kerr Engineered Sales Company are available for demonstrations, team presentations, lunch and learns and site visits. We are here to help you optimize your gas utility operations and ensure the safety and efficiency of your equipment.
Kerr Engineered Sales Company has been representing leading pipeline repair and performance companies in Eastern US since the company was founded in 1952. Seventy three years later, KERR remains a family business delivering the highest quality service and expertise.
