By: Mario Carbone, COO Progressive Pipeline Management
October, 2023
Steel gas mains come in a variety of specifics, from low to high pressure, bare to wrapped pipe, welded to coupled system; all requiring a slightly different approach when considering the reconditioning of these pipelines. With these differences, a heightened level of awareness, surrounding the readiness of the pipeline needs to be considered before the lining process can begin.
areas to be considered prior to beginning LINING process.
1. Weld lugs or anchorage must be installed, by either the utility or their contractor, before the lining process can begin.
Weld lugs are external steel fittings.
PPM is mindful that not every utility requires weld lugs or anchorage, so therefore each design will include an appendix which will mention the procedure if applicable to the utility’s needs.
Heat generated by welding can damage a lined steel pipe
Following this procedure is extremely important to the outcome of the lining process, and if overlooked by either the utility or PPM’s field supervisor at the time of the lining, the outcome of installing the weld lugs or anchorage may damage the liner which will ultimately require repair. The damaged liner is directly related to the heat generated by the welding “after” the liner was installed as seen in the photo.
2. Brazing or shooting the anode wires onto a steel main is the responsibility of the utility and performed by the utility or their contractor.
An anode wire brazed to a steel pipeline
Installing these wires is best done before lining or at least after the utility energizes the pipeline. It should not be installed after lining and before gassing the pipeline in.
PPM is mindful that not every steel pipeline requires anode wires, so therefore each design will include an appendix which will mention the procedure if applicable to meet the pipeline’s obligations.
Following this procedure is extremely important to the outcome of the lining process, and if overlooked by either the utility or PPM’s field supervisor at the time of the lining, the outcome of installing the anode wires may damage the liner which will ultimately require repair. The damaged liner is directly related to the heat generated by the brazing process. The photo is a depiction of an anode wire brazed to a steel pipeline.
3. When lining old unwrapped steel pipe that may have extensive corrosion or pitting, it is highly recommended to have a “Pup” piece of pipe (new steel pipe approximately 2-3 ft long) installed at each end of the segment of the pipe being lined.
The installation of these pup pieces will be installed by either the utility or their contractor and are to be installed as per the utility’s procedures.
The importance of the pup piece is twofold. First it makes for a much better final pressure test and tie-in for the utility. Equally as important, it allows the liner to be cut back into the pup piece, if the utility welds their final tie in. When lining a corroded or pitted steel main, installing a pup piece as shown in the sketch is advised.
In summary, Cured in-place-lining is a viable option for leaking and partially corroded steel pipelines. Our system follows ASTM standard F 2207 for the lining of partially deteriorated pipe. But as highlighted above, certain project and design parameters should be discussed in advance and put into place when the project begins in the field. PPM and our utility clients work together on the front end of this design to ensure this accessible outcome.
About PPM: Progressive Pipeline Management is a full service contractor and team of highly skilled infrastructure renewal specialists. For over twenty one years, PPM has been improving the safety and longevity of pipeline infrastructure. PPM holds the exclusive licensee in North America for the Starline® Cured-in-place-lining. The team has specialized expertise includes gas pipeline rehabilitation, restoration of damaged or leaking infrastructure, PIPES ACT 2020 compliance and trenchless technology, facilities pipe renewal and site services.
