Specifies performance and, where these are not appropriate, prescriptive requirements for seals, used in pipeline systems which convey aqueous liquids with temperatures of less than 50 degrees Celsius. The range of seal hardness is between 36 IRHD and 85 IRHD. The seals are manufactured from polychloroprene (CR), ethylene-propylene terpolymers (EPDM), polyisoprene rubber (IR), nitrile-butadiene rubber (NBR), natural rubber (NR), and styrene-butadiene rubber (SBR). Acceptance criteria are given for seals with defined imperfections. The appendices include alternative methods for the determination of the rate of compression stress relaxation and seal hardness.