An inspection port of at least four inches [101.6 millimeters] in diameter must be provided to check for malfunctioning of all antisiphon devices. The inspection port can be combined with a mounting of vacuum relief. If an airgap is used, as required by subsection 4 of section 7-10-02-02, the system is exempt from the requirement of an inspection port.
N.D. Admin Code 7-10-02-03
General Authority: NDCC 4-35.1-03
Law Implemented: NDCC 4-35.1-02, 4-35.1-03