Pipe coupling

A dry-break pipe coupling comprising a spigot member and a complementary socket member to be attached to respective ends of two pipes to be coupled, said spigot member having a mouth formed with forwardly-facing and rearwardly-facing annular valve faces and said socket member having inner and outer forwardly-facing annular valve seats, a flat sealing ring at said outer valve seat, a valve member carried by said spigot member and spring-loaded towards the rearward valve face of said mouth to close said mouth, a valve member carried by said socket member, fastening means to urge the forward valve face of the mouth of the spigot member into and secure said face in sealing engagement with the flat sealing ring at said outer valve seat of the socket member, the radially inward edge of the outer valve seat and flat sealing ring being coextensive with the inward edge of the forward valve face, operating means operable separately from said fastening means to urge the socket valve member into sealing engagement with the inner valve seat of the socket member and alternatively to move the socket valve member forwardly to engage and move the spigot valve member out of engagement with the rearward valve face of the mouth and so open the valves, first interlocking means to permit actuation of said fastening means only when the spigot member is substantially fully inserted into the socket member, and second interlocking means to permit actuation of said operating means only when said spigot and socket members are secured together in sealing engagement by said fastening means.