The TARL procedure is as follows:

1. Launch a pig train into an isolated prepped distribution mains from an assembly fixed to an upstream fire hydrant or hot tap.
2. The train contains a “compartment” of special viscous curing substances lodged between the pigs.
3. The substances operating under pressure, penetrate leaky joints, fittings & service connections and plug the leaks.
4. Pig train is extracted through a downstream fire hydrant.
5. Substance hardens and leaks are permanently cured