Ball valve with a strainer and integrated means for flushing the strainer

A ball valve (10) comprising a valve body (12) having a valve chamber (28), inlet (22) and outlet (24) ports communicating with said valve chamber (28), a rotatable ball valve element (26) disposed within the valve chamber (28) and movable between a valve open position and a valve closed position, said ball valve element (26) including means (30,32,34) defining a passage therethrough, said passage (30) defining inlet and outlet portions (32,34) therein that are in fluid alignment with said inlet and outlet ports (22,24) when said valve is in said open position, a basket strainer (38) removably mounted in the ball valve element (26) between said inlet and said outlet portions (32,34) of said passage (30) said ball valve element (26) having a rotatable shaft (44) for rotating the ball valve element (26) between said valve open position and said valve closed position, a control lever (58) connected to the ball valve element (26) rotatable shaft (44), said control lever (58) having a downwardly depending lip (70) at the end thereof for engaging stop protrusions (72,74) integrally formed on the valve body (12) when the ball valve element (26) in said open and closed positions, respectively, characterized by:

• (a) an internal pilot fluid flush passage means (116,118) is located in a portion of the valve body (12) at said inlet port (22) and connects the inlet port (22) with the ball valve element chamber (28);
• (b) a fluid flow control plug valve (122) is movably mounted in the pilot fluid flush passage means (116,118) between said inlet port (22) and said valve chamber (28), and is movable between selective open and closed positions to allow and prevent fluid flow through the pilot fluid flush passage means (116,118);
• (c) a pilot fluid flush discharge port (88) is formed in said ball valve body (12) and communicates with the ball valve element chamber (28);
• and,
• (d) a pilot fluid flush discharge valve (90) is connected to said pilot fluid discharge port (88), whereby when the ball valve element (26) is rotated to a closed position, and the fluid flow control plug valve (122) and the pilot fluid flush discharge valve (90) are moved to open positions, the upstream fluid entering the inlet port (22) will flow through the internal pilot fluid flush passage means (116,118) into the ball valve element chamber (28) through said outlet portion (34) of said passage (30) and flow through the basket strainer (38) and out the pilot fluid flush discharge valve (90), to reverse flush out debris captured by the basket strainer.