Patent ID: 8167267

Claim:
A valve comprising: a body in which there is formed a channel with an axis and which is intended to be placed between an upstream pipe and a downstream pipe; a substantially spherical rotating plug mounted in the body such that it can pivot about an axis substantially perpendicular to the axis of the channel, between a closed position and an open position, the plug having a through orifice with an axis that is intended to allow passage of fluid from the upstream pipe to the downstream pipe in the open position; an upstream seat having a central passage and mounted in the channel of the body upstream of the plug such that it can move translationally along the axis of the channel of the body; elastic means designed to urge the upstream seat toward the plug; at least one projection formed on the upstream seat and projecting substantially parallel to the axis of the channel of the body in a direction of the plug, and at least one first recess formed in the plug and designed to cooperate with the projection when the plug is in the closed position; and means for equalizing fluid pressure between the upstream end and the downstream end of the upstream seat, prior to the valve being opened; wherein the plug comprises a second recess situated substantially at the same distance as the first recess from a plane which is orthogonal to the pivoting axis of the plug and which passes through the axis of the through orifice, said second recess being designed to cooperate with the projection when the plug is in the open position; and wherein the second recess is situated substantially in the plane formed by the pivoting axis of the plug and the axis of the through orifice of the plug, the first recess being angularly separated from the second recess by an angle of between 70° and 80°.