O-ring, quantity ( 1 ) used internally in Clack By Pass ( V3006 ). PN V3156, quantity ( 2 ) used.. ONE in each port.
* If repairing By Pass - ORDER ( 2 ) TWO.
Also other "brands" that use the Clack type of valve under their private label.
Item labeled 10 in our diagram.
Cross reference CUNO PN ORG-214, ORG214