Where gas piping is to be installed in more than one portion of an expandable or multiple commercial coach, the design and construction must be as follows:

(1) There must be only one point of cross over, readily accessible from the exterior of the commercial coach.

(2) The connector between units must be a listed flexible gas connector approved for exterior use.

(3) A shut-off valve must be located on the supply side of the connection. Both a flexible gas connector that is approved for exterior use and a quick disconnect type of connector must be tested and approved to IAPMO TSC-9 standard or equal; and both must have a shut-off valve installed that is tested and approved to ANSI Z21.15 standard or equal.

(4) Protective caps or plugs must be permanently attached to the coach and used to seal the system when not in use.