Section 7.1.1/Gas Piping Installation
NFPA 54 Chapter 7 covers gas piping installation including materials, joining methods, concealed piping restrictions, and CSST bonding.
Gas piping must be installed with approved materials and joining methods. Black steel pipe with threaded or welded joints is the most common material. CSST (corrugated stainless steel tubing) must be listed and installed per the manufacturer's instructions, including the required bonding to the grounding electrode system. Concealed piping must not have unions, tubing fittings, or running threads (which can loosen over time and leak). Piping must be supported at intervals per Table 7.2.1 and protected from physical damage where exposed. Piping through foundation walls must be sleeved to allow movement and prevent damage from settlement.
Why this section exists
A gas piping leak inside a building can cause explosions and fires. The installation requirements ensure leak-tight joints, durable materials, and protection from physical damage over the life of the building. The prohibition on concealed unions prevents leak-prone joints from being hidden behind walls where leaks would go undetected. CSST bonding requirements protect against lightning-induced punctures that have caused house fires.
What plan reviewers look for
Plan reviewers check the gas piping material specification against approved materials. They verify that concealed piping uses only approved joining methods (threaded, welded, or listed press-connect for steel; listed fittings for CSST). They check for CSST bonding details on the electrical or plumbing drawings. They verify piping support at the specified intervals and protection from damage.