Self-flushing small volume prover apparatus, method and system

A method for removing foreign material, said method comprising:

• locating a piston configured with a valve arrangement located inside a cylindrical object in order to permit fluid to pass through an annular passage when said piston travels from a downstream position to an upstream position;
• mounting an outlet port and an inlet port at said bottom of said cylindrical object;
• and
• welding said outlet port at bottom of said bore cylinder in order to thereafter directly remove foreign material from said cylindrical object.

A small volume prover system, said system comprising:

• a piston maintained by and housed within a cylindrical object, said piston having with a flow-through valve arrangement that allows a fluid to pass through an annular passage when said piston travels from a downstream position to an upstream position;
• an outlet port and an inlet port located at a bottom of said cylindrical object, said outlet port located at said bottom of said cylindrical object to assist in directly removing foreign material from said precision cylinder and permit said apparatus to function as a self-flushing prover;
• and
• a sensor mounted to said piston, wherein said sensor continuously detects a velocity of said piston when said piston moves between said upstream position to said downstream position.