Final answer:
When dismantling PVC and CPVC piping systems, cutting of the joints is the recommended method. Cutting provides a controlled and safe way to disassemble the system without damaging the material, unlike heating or welding.
Step-by-step explanation:
When dismantling PVC (Polyvinyl Chloride) and CPVC (Chlorinated Polyvinyl Chloride) piping systems, cutting of the joints is recommended. This is because both PVC and CPVC are thermoplastics, which means that when they are heated to a certain temperature, they become soft and malleable. Therefore, attempting to dismantle the pipes by heating could damage both the pipes and the fittings, making it difficult to reuse them. Welding is not a feasible option since it would similarly damage the material. Freezing does not aid in dismantling; it is used more for temporary repair work to stop the flow of liquid and enable work on the system. Cutting the pipes, usually with a handsaw, ratchet cutter, or a pipe cutter, is the safest and most effective way to dismantle these systems, allowing controlled removal with minimal damage to the remaining pipe segments.