Device for carrying a replacement safety valve in a well tube

1. A device for carrying a replacement safety valve in a well tube with a straddle structure for placement inside a damaged “Down Hole Safety Valve” nipple seal area, comprising a pair of sealing assemblies ( 15 , 16 ) to be activated upon setting of the device to seal said nipple seal area, and a locking dog assembly ( 17 ) for locking the device in the well tube, said sealing assemblies and locking dog assembly being carried by a tubular mandrel ( 12 ), wherein at least one of the sealing assemblies ( 15 , 16 ) comprises an expandable element ( 22 ; 34 ) being activated by a pair of annular press elements ( 19 , 20 ), wherein each locking dog ( 61 ) is provided with a pair of axially extending torsion rods ( 69 , 70 ) to press the locking dogs ( 61 ) radially inward and each of the pair of torsion rods ( 69 , 70 ) has an outer end and an inner end, the outer ends ( 75 , 81 ) extending into and being axially movable in a circumferential groove ( 76 ), while the inner ends ( 82 , 83 ) are each engaged with a side of the locking dog ( 61 ).

2. The device of claim 1 , comprising a backup assembly ( 30 , 31 ) arranged on each side of the annular press element ( 19 ).

3. The device of claim 1 , wherein the backup assembly ( 30 , 31 ) comprises a series of arcuated backup elements ( 30 A) adjoining an outer side of the annular element ( 19 , 20 ), the arcuated elements having wings ( 44 ) and mating slots ( 45 ) to overlap.

4. The device of claim 3 , wherein the backup elements ( 30 A) are carried by a surrounding sleeve ( 29 , 21 B) by radial bolts ( 32 ), and a dish spring packet ( 33 ) is disposed on each bolt for ensuring that the backup elements are retracted.

5. The device of claim 1 , wherein the annular press elements ( 19 , 20 ) have a radially inward converging cross section.