The use of threadless couplings shall be permitted where required by the AHJ and where listed for such use.

• A. Not permitted
• B. Permitted only if listed
• C. Permitted where required by AHJ and listed
• D. Permitted universally

Answer: (C)

Threadless couplings in foam-water systems are governed by two assurances: the Authority Having Jurisdiction (AHJ) and product listing. The AHJ may require their use for specific design reasons or installation conditions, and the device itself must be listed for that particular application by a recognized testing organization. Listing confirms the component has been evaluated for the intended service, including compatibility with foam concentrates, pressure ratings, and long-term performance. Because both conditions need to be met, the only acceptable scenario is that threadless couplings are permitted where the AHJ requires them and where the parts are listed for such use. Without either the AHJ requirement or the appropriate listing, they are not approved.