Patent ID: 8672036

Claim:
A circulation valve comprising: a tubular mandrel including an inboard end, an opposite end formed for connection into a tubular string and an inner bore extending from the inboard end to the opposite end; an outer tubular sleeve including a first end, a second end, an outer surface and an inner facing surface defining an inner bore extending from the first end to the second end, the outer tubular sleeve being telescopically mounted at its second end over the inboard end of the tubular mandrel with an inner facing surface of the second end encircling an outer facing surface of the inboard end and the inner bore of the outer tubular sleeve in communication with the inner bore of the tubular mandrel such that a fluid flow path is open from the first end to the opposite end, the outer tubular sleeve being axially moveable relative to the inboard end of the tubular mandrel between a fully compressed position and a fully in tension position; a fluid passage between the inner facing surface of the second end and the outer facing surface of the inboard end, the fluid passage providing fluid communication between the fluid flow path and the outer surface of the outer tubular sleeve; a dual knife seal assembly to control flow out of the fluid flow path through the fluid passage, the dual knife seal assembly including a first annular knife seal edge, a first annular knife seal land positioned to seal with the first annular knife seal edge when the outer tubular sleeve and the tubular mandrel are in the fully compressed position, an opposite annular knife seal edge and an opposite annular knife seal land positioned to seal with the opposite annular knife seal edge when the outer tubular sleeve and the tubular mandrel are in the fully in tension position; and, a J-slot position indexing mechanism including a slot and a key to guide movement of the outer tubular sleeve and the tubular mandrel between the fully in tension position and the fully compressed position.