Abstract: A pipe joint comprises a pin having a male screw-threaded portion and a box having a complementary screw-threaded portion. The threaded portions of the pin and box inter-engage along the greater part of the axial length of the threaded portions, the male thread extending to a male stop shoulder adjacent a complementary stop shoulder on the other portion. The pin further comprises a radial surface adjacent a corresponding radial surface on the complementary stop shoulder of the box, a curved sealing surface of the radial surface on the pin sealingly engaging a corresponding curved sealing surface on the corresponding radial surface on the complementary stop shoulder. Each of the curved sealing surfaces is so shaped to lie on an arc of a separate ellipse. The parameters of the ellipses are carefully chosen to maximize the strength and robustness of the seal.

Abstract: A screw-threaded pipe joint comprising a pin having at one end a male screw-threaded portion and a box having at one end a female portion having a complementary screw-thread. The pin and box inter-engage along the threaded portions with the male thread extending to a male stop shoulder adjacent a complementary stop shoulder on the other portion. The complementary stop shoulder comprises a recess in the form of a cone receiver having a radial surface adjacent a corresponding radial surface on the complementary stop shoulder. A curved sealing surface on the pin sealingly engages a corresponding curved sealing surface on the complementary stop shoulder of the box, each curved sealing surface lying on the arc of the circumference of a separate circle, and wherein the curvature of the box sealing surface is greater than on the sealing surface on the pin.

Abstract: The invention relates to a screw-threaded pipe joint comprising a pin (20) having at one end a male screw-threaded portion and a box (10) having at one end a female portion having a complementary screw-thread. The pin and box inter-engage along the threaded portions with the male thread extending to a male stop shoulder adjacent a complementary stop shoulder on the other portion. The complementary stop shoulder comprises a recess in the form of a cone receiver having a radial surface (23) adjacent a corresponding radial surface (15) on the complementary stop shoulder. A curved sealing surface (24) on the pin (20) sealingly engages a corresponding curved sealing surface (16) on the complementary stop shoulder of the box (10), each curved sealing surface (16,24) lying on the arc of the circumference of a separate circle, and wherein the curvature of the box sealing surface (16) is greater than on the sealing surface (24) on the pin (20).

Abstract: A pipe joint comprises a pin having a male screw-threaded portion and a box having a complementary screw-threaded portion. The threaded portions of the pin and box inter-engage along the greater part of the axial length of the threaded portions, the male thread extending to a male stop shoulder adjacent a complementary stop shoulder on the other portion. The pin further comprises a radial surface adjacent a corresponding radial surface on the complementary stop shoulder of the box, a curved sealing surface of the radial surface on the pin sealingly engaging a corresponding curved sealing surface on the corresponding radial surface on the complementary stop shoulder. Each of the curved sealing surfaces is so shaped to lie on an arc of a separate ellipse. The parameters of the ellipses are carefully chosen to maximize the strength and robustness of the seal.

Abstract: A pipe connector comprises an internally threaded female member and an externally threaded male member for threaded engagement in the female member. When the members are fully engaged together, an axially and radially directed surface at the free end of one of the members, e.g. the male member, is abutted against a corresponding surface on the other member, e.g. the female member. The surface comprises radially inwardly and outwardly curved surface portions which are relatively dimensioned to be a radial force fit such as to cause deflection of the end portion of the free end of the male member away from the female member as the members are brought into full engagement to bring the surfaces into full engagement.

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 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 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 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.