What rule applies to solder joints on underground gas lines?

In the context of underground gas lines, the prohibition of solder joints is based on safety standards and regulatory requirements that aim to minimize the risk of leaks and hazardous situations. Solder can weaken when subjected to environmental conditions such as soil movement or moisture, which can lead to joints failing over time.

Moreover, many gas codes and safety regulations, including those established by organizations like the National Fire Protection Association (NFPA) and various plumbing codes, specifically dictate that gas line connections must be made with fittings that maintain integrity and reliability under varying soil conditions. This is to prevent any possible gas leaks, which could pose serious safety hazards.

Using approved mechanical fittings or welding instead of solder joints ensures a stronger, more dependable connection that stands up to the rigors of underground installation. Therefore, the rule that prohibits solder joints on underground gas lines is a crucial safety guideline in plumbing practices.