Subsea blind stab device
A subsea blind stab ( 100 ), comprises a stabbing part ( 110 ) for insertion into a hot stab receptacle, the stabbing part ( 110 ) including a housing, a central rod ( 150 ) slidably arranged within the housing and at least one fluid communication line from the external side of the stabbing part ( 110 ) to an internal fluid communication line ( 180 ) within the rod ( 150 ). The at least one fluid communication line is open in a first position of the rod ( 150 ) relative the housing and closed in a second position of the rod ( 150 ) relative the housing. The stab ( 100 ) further comprises a hollow body ( 120 ) attached to one end of the stabbing part ( 110 ); a piston ( 130 ) slidably arranged in the hollow body ( 120 ), with a spring element ( 160 ) arranged between the piston ( 130 ) and a spring attachment element ( 170 ) connected to the body. A first side of the piston ( 130 ) forms a fluid chamber ( 140 ) in the hollow body. The fluid chamber ( 140 ) is in fluid communication with the internal fluid communication line in the rod, and a second side of the piston ( 130 ) is exposed to a pressure of the surrounding environment.
1. A subsea blind stab comprising:
a stabbing part for insertion into a hot stab receptacle, the stabbing part including:
a housing;
a central rod slidably arranged within the housing; and
at least one fluid communication line extending from an external side of the stabbing part to an internal fluid communication line within the rod;
the at least one fluid communication line being open in a first position of the rod relative the housing and closed in a second position of the rod relative the housing,
wherein the subsea blind stab further comprises:
a hollow body attached to one end of the stabbing part;
a piston slidably arranged in the hollow body; and
a spring element arranged between the piston and a spring attachment element connected to the body;
wherein a first side of the piston forms a fluid chamber in the hollow body which is in fluid communication with the internal fluid communication line in the rod, and wherein a second side of the piston is exposed to a pressure of a surrounding environment.
2. The subsea blind stab according to claim 1 , wherein the rod is arranged to slidably extend through a bore in the piston.
3. The subsea blind stab according to claim 1 , wherein the spring element is arranged around the rod on the second side of the piston.
4. The subsea blind stab according to claim 1 , further comprising a check valve arranged between the fluid chamber and the surrounding environment.
5. The subsea blind stab according to claim 4 , wherein the check valve is arranged in the piston.
6. The subsea blind stab according to claim 1 , wherein an end of the rod is provided with a ROV handle.
7. The subsea blind stab according to claim 6 , wherein the end of the rod is also provided with a position indicator which indicates if the rod is in the first or second position.
8. The subsea blind stab according to claim 1 , wherein the second side of the piston is exposed to the surrounding environment by means of at least one aperture through the body.
9. The subsea blind stab according to claim 8 , wherein the body is formed by two end sections and a side wall.
10. The subsea blind stab according to claim 1 , wherein the stabbing part and the body are substantially cylindrical and coaxial.
11. The subsea blind stab according to claim 10 , further comprising:
an ROV handle connected to an end of the rod; and
a rotary-to-linear conversion mechanism for converting a rotational operation of the ROV handle to an axial movement of the rod.
12. The subsea blind stab according to claim 1 , wherein the fluid chamber is filled with hydraulic fluid at a predetermined pressure.
13. A method for protecting a subsea equipment comprising:
inserting a subsea blind stab into a hot stab receptacle of the subsea equipment; or
removing the subsea blind stab from the hot stab receptacle of the subsea equipment;
wherein the subsea blind stab comprises:
a stabbing part configured for insertion into the hot stab receptacle and including a housing, a central rod slidably arranged within the housing, and at least one fluid communication line extending from an external side of the stabbing part to an internal fluid communication line within the rod, the at least one fluid communication line being open in a first position of the rod relative the housing and closed in a second position of the rod relative the housing;
a hollow body attached to one end of the stabbing part;
a piston slidably arranged in the hollow body; and
a spring element arranged between the piston and a spring attachment element connected to the body;
wherein a first side of the piston forms a fluid chamber in the hollow body which is in fluid communication with the internal fluid communication line in the rod, and wherein a second side of the piston is exposed to a pressure of a surrounding environment.
14. The method for protecting a subsea equipment according to claim 13 , wherein the subsea blind stab comprises an ROV handle connected to an end of the rod, and wherein the step of inserting the subsea blind stab into the hot stab receptacle or removing the subsea blind stab from the hot stab receptacle is performed at a subsea location by a Remotely Operated Vehicle (ROV).