(a) Except as provided in subdivision (b) of this section, buried high-pressure service line valves or exposed exterior high-pressure service line valves shall be inspected in conjunction with the service regulator inspection required under section 255.744 of this Part.
(b) Buried service line valves used for compliance with section 255.365(b)(2) of this Part, shall be inspected at intervals not exceeding 15 months, but at least once each calendar year, for accessibility, key alignment and external leakage.
(c) Each buried service line valve inspection shall determine accessibility, key alignment and tests for external leakage. Each exposed exterior service line valve shall be inspected for accessibility and external leakage.