Abstract: An adjustable weir for use in a liquid distribution system utilizes a weir plate having a weir opening whose height can be adjusted vertically. The weir plate is mounted to the end of a fluid distribution outlet in a manner which will maintain its proper orientation while allowing its vertical position with respect to the outlet opening to be varied.

Abstract: A weir construction for regulating liquid flows in conduits or containers having a liquid-gas interface under the influence of gravity or acceleration. Uniform flow distribution between weirs or exact division of flow in other ratios is obtained over a wide range of flow rates by using a weir so shaped that the percent flow error beween two weirs having different heads shall be constant over the range of flow rates. This results in weirs having a modified cusp appearance.

Abstract: A composite weir construction for evenly dividing liquid flows in conduits or containers having a liquid-gas interface under the influence of gravity or accelleration is presented. In particular, this device is for flows wherein clogging of narrow weirs is a problem, and where weir elevation differences are also a problem. When these weirs are placed in the flow, new weirs are gradually formed which is are composites made from the clogging agent and the original weirs. These new composite weirs are very accurate in flow division over a wide range of flows in spite of substantial vertical misalignment of the original weirs.