Hydraulic tensioning flange connector

1. A flange connector for connecting first and second flange components, the first flange component having first and second sides and having a connector hole with first and second open ends on the first and second sides and having a hydraulic port communicating with the connector hole, the second flange component having third and fourth sides, the third side of the second flange component positioned adjacent the second side of the first flange component, the connector comprising:

a piston disposed in the connector hole and movable therein in at least one direction by hydraulic pressure applied through the hydraulic port;

a first stud connected to the piston and having a first end extending beyond the first open end of the connector hole for connection to a first nut on the first side of the first flange component; and

a second stud connected to the piston and having a second end extending beyond the second open end of the connector hole to the second flange component for connection to a second nut on the fourth side of the second flange component,

wherein the movement of the piston in the at least one direction by the hydraulic pressure pulls at least one of the first and second studs in tension in the at least one direction against the corresponding nut connected thereto.

2. The connector of claim 1 , wherein the first or second stud is integrally formed to the piston.

3. The connector of claim 1 , wherein the first or second stud threads into a threaded end of the piston.

4. The connector of claim 1 , further comprising a retainer disposed in the second open end of the connector hole, the retainer retaining the piston therein and having the second stud pass therethrough.

5. The connector of claim 4 , wherein the retainer comprises an external seal sealably engaging the connector hole and comprises an internal seal sealably engaging the second stud.

6. The connector of claim 4 , wherein the retainer threads into the second open end of the connector hole.

7. The connector of claim 4 , wherein the retainer comprises:

a washer having internal and external seals for sealing between the connector hole and the second stud; and

a third nut threading into the second open end of the connector hole and holding the washer therein.

8. The connector of claim 1 , wherein the second end of the second stud extends through a stud hole defined through the third and fourth sides of the second flange component and receives the second nut threaded thereon.

9. The connector of claim 1 , wherein the first end of the first stud extends through a stud hole in a third flange component positioned adjacent the first side of the first flange component and receives the first nut threaded thereon.

10. The connector of claim 1 , further comprising a pump coupling to the hydraulic port for applying the hydraulic pressure to the piston in the connector hole.

11. The connector of claim 10 , wherein a fitting and check valve couples the pump to the hydraulic port.

12. The connector of claim 1 , wherein a spring biases the piston in a direction opposite to the at least one direction.

13. A flange connection, comprising:

a first flange component having first and second sides and having at least one connector hole defined therein, the at least one connector hole having first and second open ends on the first and second sides and having a hydraulic port communicating with the at least one connector hole;

a connector for connecting the first flange component to a second flange component having a third side positioned adjacent the second side of the first flange component and having a fourth side, the connector at least including—

a piston disposed in the at least one connector hole and movable therein in at least one direction by hydraulic pressure applied through the hydraulic port;

a first stud connected to the piston and having a first end extending beyond the first open end,

a first nut connected to the first end of the first stud on the first side of the first flange component,

a second stud connected to the piston and having a second end extending beyond the second open end to the second flange component,

a second nut connected to the second end of the second stud on the fourth side of the second flange component,

wherein the movement of the piston in the at least one direction by the hydraulic pressure pulls at least one of the first and second studs in tension in the at least one direction against the corresponding nut connected thereto.

14. The flange connection of claim 13 , wherein the at least one connector hole defines an outlet port.

15. The flange connection of claim 13 , wherein the first flange component is an element of a blowout preventer installing on a casing head as the second flange component.

16. The flange connection of claim 13 , wherein the first flange component defines a plurality of the connector holes, and wherein the flange connection comprises a plurality of the connectors disposed in the connector holes.

17. The flange connection of claim 13 , wherein the first flange component connects to a third flange component positioned at another end of the first flanged component.

18. The flange connection of claim 17 , further comprising a double-ended stud and two third nuts connecting the first flange component to the third flange component.

19. The flange connection of claim 17 , wherein the first end of the first stud extends through a stud hole in the third flange component and receives the first nut threaded thereon.

20. The flange connection of claim 13 , wherein the first open end of the at least one connector hole defines a first diameter comparable to the first stud, and wherein the second open end defines a second diameter greater than the first diameter and forms a chamber for the piston therein.