What must be installed where a nonmetallic gas hose connector is attached to the building piping?

The requirement for a shutoff valve at the connection point of a nonmetallic gas hose to the building piping is primarily rooted in safety and convenience. A shutoff valve allows users to quickly and easily stop the flow of gas in the event of an emergency or for maintenance purposes. This is crucial in minimizing the risk of gas leaks and ensuring that any necessary service work can be done safely without disconnecting the entire system.

In practical terms, this valve serves as a critical control point in the gas supply line, thus, ensuring that at no time is there uncontrolled gas flow when the connector is not in use. This is especially important in scenarios where a nonmetallic hose might be used for mobile equipment or appliances, allowing for swift disengagement from the gas supply without exposing users to the hazards of a gas leak.

While other components like regulators, safety valves, and expansion joints serve essential functions within a gas system, they do not fulfill the specific role of providing immediate control over gas flow at the point of connection like a shutoff valve does. A regulator controls pressure, a safety valve prevents overpressure, and an expansion joint accommodates thermal expansion and contraction, none of which replace the need for a shutoff valve to manage gas flow directly at the connection