Hydraulically operated valve and systems for use therewith

A diaphragm actuated by hydraulic pressure, for use with a weir type valve having a valve body including an inlet extending into an upstream chamber, an outlet extending from a downstream chamber defining together with the inlet a main flow path for liquid to flow in through the weir type valve, and a weir disposed therebetween, said diaphragm comprising:

• a circumferential portion configured to be fixedly held by said valve body;
• a reinforced central portion having a top face configured to face away from said weir, and an opposite bottom face divided into an upstream face configured to face said upstream chamber, and a downstream face configured to face said downstream chamber, said reinforced central portion being movable with respect to said circumferential portion, by hydraulic pressure applied by said liquid, between a lower position at which said reinforced central portion is configured to be compressed against said weir, thereby sealing said main flow path, to an upper position at which said reinforced central portion is configured to be spaced from said weir, thereby enabling said main flow path;
• said reinforced central portion having a lower region with a first bendability, allowing said upper region to maintain its shape at least during movement of the reinforced central portion at least in between said lower and upper positions, and an upper region with a second bendability greater than said first bendability allowing said upper region to facilitate said movement;
• wherein said lower region has a concave face, constituting a lowermost portion of said bottom face, and said upper region has a circular face constituting an uppermost portion of said bottom face, and wherein said reinforced central portion has an axis extending tangent to an apex of the convex face, in a direction from the upstream face to the downstream face, and wherein at a cross section of the diaphragm taken along said axis, a contour of said convex face is greater than a contour of said circular face,
• wherein said reinforced central portion comprises an upstream portion associated with said upstream face, and having a first volume, and an opposite downstream portion associated with said downstream face, having a second volume greater than said first volume.