Self-relieving ball valve seat

A system, comprising:

• a unitary annular ball valve seat disposed within an annular groove of a valve housing for use in a ball valve, wherein the unitary annular ball valve seat comprises a main body section and a lip section, the main body section defines opposite first and second axial surfaces and radially-inner and radially-outer circumferential surfaces, and the lip section is recessed below the radially-outer circumferential surface;
• and
• an annular spring disposed within a seat groove of the unitary annular ball valve seat, wherein the seat groove extends radially into the radially-outer circumferential surface of the unitary annular ball valve seat at a position axially between the first and second axial surfaces of the unitary annular ball valve seat, the annular spring biases the opposite first and second axial surfaces of the unitary annular ball valve seat axially into contact with a ball and the valve housing, and the annular spring comprises a first leg and a second leg that are configured to be parallel to one another such that respective radially-outer ends of the first leg and the second leg are separated by a first axial distance during certain pressure conditions within the ball valve and to be angled relative to one another such that the respective radially-outer ends of the first leg and the second leg are separated by a second axial distance that is less than the first axial distance during other pressure conditions within the ball valve.

A system, comprising:

• a valve housing comprising an annular groove;
• a ball disposed in the valve housing;
• a unitary annular ball valve seat disposed within the annular groove, the unitary annular ball valve seat comprising axially opposite first and second axial surfaces, the first surface comprises a first straight angled portion and a second straight angled portion, the first straight angled portion defines a first length and the second straight angled portion defines a second length, wherein the second length is greater than the first length, wherein the first and second straight angled portions are radially offset from each other and acutely angled relative to a central axis of the unitary annular ball valve seat, wherein the radial offset is configured to block contact between the first straight angled portion and the ball such that only the second straight angled portion, and not the first straight angled portion, contacts the ball while the ball is in a closed position within the valve housing with the unitary annular ball valve seat downstream such that a first pressure in a first bore on a first side of the ball adjacent to the first unitary annular seat is less than a second pressure in a second bore on a second side of the ball opposite from the first unitary annular seat, and wherein the unitary annular ball valve seat is configured to self-relieve;
• and
• an annular spring disposed within a seat groove of the unitary annular ball valve seat, wherein the seat groove extends radially into a radially-outer circumferential surface of the unitary annular ball valve seat at a position axially between the first and second axial surfaces of the unitary annular ball valve seat, and the annular spring biases the opposite first and second axial surfaces of the unitary annular ball valve seat axially into contact with the ball and the valve housing.