LP Encapsulation (PDF)
Parts List
Since natural gas was introduced into cast iron pipes, the jute packing has dried out and the lead has moved. The result is joint leakage. PLCS Encapsulation provides a permanent repair to leaking joints.
Used by more than 50 major gas utilities in the USA.
- The proven, permanent solution to bell joint leaks!
- Don’t replace cast iron pipes. Make them as good as new by encapsulating the joints with PLCS products.
- Over the last 40+ years, millions of joints have been permanently sealed by PLCS encapsulation.
- Tests by Cornell University (for the New York Gas Group) and British Gas prove 50 years minimum life expectancy.
- The joint is encapsulated in a tough, flexible layer of synthetic rubber that is permanently adhered to the pipe, yet allows the joint to move.
- A 6″ bell joint can be sealed in less than 15 minutes.
Low-Pressure Bell Joint Encapsulation
Steel Band Installation
PLCS ENCAPSULATION is a very simple process whereby a few inches of pipe either side of the leaking joint are cleaned down to bare metal using a small portable grit blaster working from the crew’s air compressor. Although there is a perception that this is difficult or hard work, it is very fast and easy, taking about 5 minutes for a 6” (150mm) bell joint. The operator wears a helmet fed with cool air so that even on a hot day he is one of the cooler men in the crew.
Primer is brushed onto the joint area and a fabric mold wrapped around the joint and secured with Velcro. The mold fastens to the pipe with plastic ties or steel bands using hand tools. A two-part polyurethane sealant is mixed for one minute and poured into the mold. Then the sealant is pressurized to above mains pressure by twisting down the mold neck. This action stops the leak, as gas cannot leak from low pressure to a higher pressure.
The whole process takes about 15 minutes for a small bell joint. Over the next hour, the sealant cures to a solid, flexible synthetic rubber, which permanently adheres to the pipe joint and completely encapsulates it. If care is taken not to damage the fabric mold, backfilling can begin immediately. The encapsulated joints seals for the lifetime of the pipe, no matter how the pipe joint subsequently flexes and moves, it will never leak again.
Once operators have obtained experience with encapsulating low-pressure bell joints, they can move on to other types of joints such as mechanical, coupling or split sleeves. Later they can move up to fabric molds for mains pressures up to 25 psi. Eventually, they can encapsulate almost any configuration of joint or fitting with a custom made special kit. Leaks at pressures up to 60 psi use a custom made, reusable metal mold to enclose the encapsulant. Training is available at every stage.