Enclosures

(a)If enclosed, individual pressure regulating or relieving devices in series and in the same system, shall be in at least two separate physical enclosures, such that damage to one enclosure does not render any device in the other enclosure inoperable. This subsection does not apply to support or pilot devices required to allow the operation of a pressure regulating or relieving device.#

(b)Equipment located in below-ground enclosures, where a malfunction could directly impact the safe operation and reliability of a Pipeline, shall be designed to continue operating normally if submerged.#

(c)Each Operator shall ensure that snow or ice accumulation that would significantly delay access to a Vault is removed as soon as practicable after the accumulation. 28#