This document is applicable to pressure-vacuum valves and to devices to prevent the passage of flame, both protecting cargo tanks, that can be subject to explosive gas/vapour and/or to gas/vapour pressure or vacuum beyond the design parameters of the system/tank. It specifies the minimum requirements for performance and testing. It also specifies design and in-service performance criteria, operational testing and maintenance requirements. Design or manufacturing in accordance with this document does not imply suitability for any given installation, it indicates that certain minimum requirements have been considered and that information necessary for determination of suitability is provided to the buyer of the equipment.The flame test procedures of ISO 16852:2016 are incorporated in this document.NOTE Minimum requirements for devices to prevent the passage of flame are found in the International Maritime Organization (IMO) "International Convention for the Safety of Life at Sea, as amended" (SOLAS), Chapter II-2, Regulation 4, and IMO Maritime Safety Committee (MSC) Circular No. 677 (MSC/Circ. 677), "Revised Standards for the Design, Testing and Locating of Devices to Prevent the Passage of Flame into Cargo Tanks in Tankers", as amended.