A fluid flow valve, the fluid flow valve having a body comprising a body inlet, a body outlet, and a housing; a movable member positioned within the housing and having a lower face, the movable member being movable between a position spaced from a position in said body when said valve is in an open position and movable to a sealing position when said valve is in a closed position; an elongated channel between the body inlet and the body outlet, wherein the channel has at least an essentially uniform internal diameter, with the exception of a raised seat therein, from the body inlet to the body outlet, and a raised seat positioned within the channel, wherein the lower face of the movable member is in the sealing position when positioned against the raised seat and a lip formed in the body.