Abstract: A connector, for example for connecting pipe sections, comprises a female member having threaded internal circumferential surfaces at each end, for engagement with a pair of male members each of which is provided with a threaded external circumferential surface. Each male member is provided with an annular nose having an axially directed primary sealing surface for sealing abutment with the primary sealing surface of the other male member, and a circumferential secondary sealing surface for sealing against a secondary sealing surface on the female member. The sealing surfaces being initially shaped so that when the noses are initially brought into contact there are progressively widening axial and radial gaps therebetween which are closed by deformation of the noses when the members are fully engaged together.

Abstract: A connector, for example for connecting a tubular member such as a pipe, comprises a male member which has an external frusto-conical surface provided with a thread and a female member having an internal frusto-conical surface provided with a thread for engagement will the thread of the male member. The members are provided with generally radially directed sealing surfaces which are brought into sealing abutment under an axially directed compressive force when the members are fully engaged together. To improve the loading of the threads of the members on engagement of the members and on application of a tensile load to the engaged members, the axial thickness of the thread of at least one of the members in one or both of the portions of the thread adjacent the ends thereof is reduced to increase the flexibility of the thread and therefore reduce the load sustaining ability of the thread.

Abstract: A connector, for example for connecting a tubular member such as a pipe, comprises a male member which has an external frusto-conical surface provided with a thread and a female member having an internal frusto-conical surface provided with a thread for engagement with the thread of the male member. The members are provided with sealing surfaces which are brought into sealing abutment under an axially directed compressive force when the members are fully engaged together, as a result of which one member, as shown in FIG. 3 the male member, is partly compressed and the other member, as shown in FIG. 3 the female member, is partly tensioned.

Abstract: A connector, for example for connecting a tubular member such as a pipe, comprises a male member which has an external frusto-conical surface provided with a thread and a female member having an internal frusto-conical surface provided with a thread for engagement with the thread of the male member. The members are provided with sealing surfaces which are brought into sealing abutment under an axially directed compressive force when the members are fully engaged together, as a result of which one member is partly compressed and the other tensioned. To improve the load distribution along the threads of the members, the pitch of the thread is varied along the axial length of the threaded surfaces. Specifically the surfaces are divided into three portions, an intermediate portion in which the pitches of the threads of the members are the same, and end portions at either end of the intermediate portion, in which the pitches of the threads differ.