Subsurface well safety valve with hydraulic strainer

In combination with a subsurface safety valve for controlling fluid flow through a well conduit and including a housing having a bore and a valve closure member moving between open and closed positions for controlling fluid flow through the bore, a flow tube telescopically moving in the housing for controlling the movement of the valve closure member, biasing means for moving the tubular member in a direction to close the valve and a hydraulic piston and cylinder assembly for actuating the valve closure member, of a hydraulic strainer comprising,

• means defining a closed chamber positioned above the hydraulic piston and cylinder assembly,
• means defining an inlet fluid passageway having first and second ends, said first end adapted to receive hydraulic control fluid through a control line from the well surface, said second end extending into the chamber,
• means defining an outlet fluid passageway having first and second ends, said first end of said outlet fluid passageway extending into the chamber, and the second end of said outlet fluid passageway connected in fluid communication to the top of the hydraulic piston and cylinder assembly,
• the second end of the inlet fluid passageway being positioned away from the first end of the outlet fluid passageway for allowing debris to accumulate in the chamber and protect the piston and cylinder assembly.