Anti-contamination valve for powder delivery system

A system for delivering powder coating material, comprising:

• a source of virgin powder coating material;
• a sieve having an inlet communicating with said source, and an outlet;
• a powder transfer device having an inlet for receiving powder coating material, and an outlet adapted to communicate with at least one powder spray gun;
• a valve connected between said outlet of said sieve and said inlet of said powder transfer device, said valve comprising:
• (i) a valve body having an interior including an inlet adapted to communicate with a source of powder coating material, and an outlet adapted to communicate with at least one powder spray gun;
• (ii) a closure member carried within said interior of said valve body between said inlet and said outlet, said closure member being movable between an open position and a closed position;
• (iii) a sealing member mounted to one of said valve body and said closure member, said sealing member being effective to create a seal between said closure member and said valve body in said closed position of said closure member to substantially isolate said inlet of said valve body from said outlet thereof;
• and
• said valve, with said closure member in said closed position, being effective to isolate said sieve from powder coating material within said powder transfer device and downstream therefrom to avoid contamination of such powder coating material during cleaning of said sieve.