Section 35.35-4 - Insulating flange joint or nonconductive hose-TB/ALL(a) A vessel's cargo hose string or vapor recovery hose must use an insulating flange or one continuous length of nonconductive hose between the vessel and the shore transfer facility. For each vapor recovery hose or cargo hose string, only one insulating flange or non-conductive hose must be provided. See 33 CFR 154.2101(g) .(b) The insulating flange must be inserted at the jetty end and take all reasonable measures to ensure the connection will not be disturbed. The hose must be suspended to ensure the hose-to-hose connection flanges do not rest on the jetty deck or other structure that may render the insulating flange ineffective or short circuited by contact with external metal or through the hose handling equipment.(c) The insulating flange must be inspected and tested at least annually, or more frequently if necessary due to deterioration caused by environmental exposure, usage, and damage from handling. After installation, the insulation reading between the metal pipe on the shore side of the flange and the end of the hose or metal arm when freely suspended must not be less than 1,000 ohms. A suitable DC insulation tester must be used.USCG-1999-5150, 78 FR 42641 , July 16, 2013