Abstract: A production string pressure relief system comprising a hollow cylindrical housing with an outer wall, a first relief valve assembly that is mounted on a first support base that is welded to the outer wall of the housing, and a second relief valve assembly that is mounted on a second support base that is welded to the outer wall of the housing directly opposite the first support base. Each of the first and second relief valve assemblies comprises a valve element that is in the shape of a spherical segment with a spherical sealing face, a cylindrical valve seat with a circular sealing face, and a leaf spring. The leaf spring provides a biasing force that pushes the spherical sealing face of the valve element against the circular sealing face of the valve seat to form a fluid-tight seal when the valve is in a normally closed position.

Abstract: A polish rod seal comprising: a post with a bottom end, top part, and circumferential flange situated between the bottom end and top part; a collar that fits over the top part of the post, the collar having one or more internal channels into which O-rings are inserted and positioned between the collar and top part of the post; and a barrel with a bottom end and two internal bushings, each of which has one or more internal channels into which O-rings are inserted. The bottom end of the barrel screws into the top part of the post. A bracket is attached to the circumferential flange and secures the collar on the top part of the post while still allowing it to flex on the post. A polish rod extends through the post, collar and barrel and is in contact with the O-rings in the internal bushings.

Abstract: A production string pressure relief system comprising a hollow cylindrical housing with an outer wall, a first relief valve assembly that is mounted on a first support base that is welded to the outer wall of the housing, and a second relief valve assembly that is mounted on a second support base that is welded to the outer wall of the housing directly opposite the first support base. Each of the first and second relief valve assemblies comprises a valve element that is in the shape of a spherical segment with a spherical sealing face, a cylindrical valve seat with a circular sealing face, and a leaf spring. The leaf spring provides a biasing force that pushes the spherical sealing face of the valve element against the circular sealing face of the valve seat to form a fluid-tight seal when the valve is in a normally closed position.

Abstract: A polish rod seal comprising: a post with a bottom end, top part, and circumferential flange situated between the bottom end and top part; a collar that fits over the top part of the post, the collar having one or more internal channels into which O-rings are inserted and positioned between the collar and top part of the post; and a barrel with a bottom end and two internal bushings, each of which has one or more internal channels into which O-rings are inserted. The bottom end of the barrel screws into the top part of the post. A bracket is attached to the circumferential flange and secures the collar on the top part of the post while still allowing it to flex on the post. A polish rod extends through the post, collar and barrel and is in contact with the O-rings in the internal bushings.