Self draining valve member for use in underground water lines

A self draining valve member for use with a water line of an underground water distribution system, said valve member comprising

• a first conduit having first and second ends and a cylindrical outer surface
• screw threads formed on at least a portion of said outer surface which is adjacent to the first end of said conduit, wherein said screw threads are adapted to engage a threaded fitting on the water line such that said first end of said conduit is in fluid flow communication with said water line;
• a first bore extending axially inward from the first end of said conduit;
• a second bore extending axially inward from the second end of said conduit;
• a transverse wall positioned across an intermediate section of the conduit to separate the first and second bores, with opposite first and second sides of said transverse wall being substantially flat and forming the innermost ends of the first and second bores, respectively;
• a drain bore extending through the transverse wall to establish flow communication between said first and second bores, with said drain bore having a reduced passage relative to either of the first and second bores;
• a first valve seat formed by the substantially flat first side of said transverse wall circumscribing said drain bore at the inner end of said first bore;
• a second valve seat formed by the substantially flat, second side of said transverse wall circumscribing said drain bore at the inner end of said second bore;
• a first, resilient valve head in said first bore, said valve head having a face which seats on said first valve seat;
• a second resilient valve head in said second bore to seat on said second valve seat;
• a valve stem extending through said drain bore and connecting said first and second valve heads, wherein said valve stem has a length somewhat greater than the distance along the drain bore between said first and second sides of said transverse wall,
• whereby said first valve head responds to a minimum water pressure in said water line to seat against said first valve seat to inhibit flow of water from said conduit through said drain bore and allows water in said water line to drain through said drain bore when there is less than the minimum water pressure in the water line, with said second valve head being capable of seating against said second valve seat in response to pressure of ground water to inhibit backflow of ground water into the water line,
• with said valve member further comprising
• a flange projecting circumferentially from said second end of said conduit;
• a hollow cylindrical hood extending from said flange away from said conduit;
• internal screw threads formed on at least a portion of the internal surface of said hood which is adjacent to said flange;
• a threaded plug which engages said internal threads from the open end of said hood such that one end of said threaded plug can be screwed tightly against said second end of said conduit, with the other end of said threaded plug facing away from said conduit;
• an opening through said threaded plug which establishes flow communication between said second end of said conduit and said hollow, cylindrical hood;
• and
• a porous filter element sealed between said second end of said conduit and said threaded plug when said threaded plug is screwed against said second end of said conduit,
• whereby said threaded plug and said porous filter element form a closed end of said second bore in said conduit to prevent foreign, solid objects such as dirt and pebbles from infiltrating into said second bore.