Abstract: An apparatus (16) for preventing stagnation in a fluid reservoir (2) comprised of: an inlet/outlet conduit (6); a manifold (8), which communicates the inlet/outlet conduit (6) to inlet check valves (10) and outlet check valves (12); the inlet check valves (10) being positioned on the manifold (8) and being oriented such that a fluid (14) will flow from the manifold (8) through the inlet check valves (10) to the reservoir (2) during reservoir filling and fluid flow is prevented through the inlet check valves (10) during reservoir draining; and the outlet check valves (12) being positioned on the manifold (8) and spaced from the inlet check valves (10) to provide fluid flow within the reservoir (2) in the general direction from the inlet check valves (10) to the outlet check valves (12), the outlet check valves (12) being oriented such that fluid flows from the reservoir (2) through the outlet check valves (12) into the manifold (8) during reservoir draining and fluid flow through the outlet check valves (12) i

Abstract: A half-sleeve pinch valve includes a first body member and a second body member. The first body member and the second body member are connected to define a passage. A semi-circular sleeve is positioned within the passage such that a middle portion of the sleeve is adjacent either the first body member or the second body member, defining a fully open state. A port is located in either the first body member or the second body member adjacent the sleeve and is in fluid communication with the passage. A closing fluid is introduced through the port into the passage, thereby displacing the middle portion of the sleeve into the passage to move the sleeve from the fully open state through a partially open or partially closed state to a fully closed state. A method for controlling the flow in a passage is also disclosed.

Abstract: A support mechanism for a tide gate valve having an internal cavity, wherein the support mechanism includes a support body receivable in the tide gate valve cavity to help prevent the tide gate valve from collapsing in on itself when subjected to backflow pressure. The support mechanism is positioned adjacent to a pipe end and can take the shape of a ring having legs or flanges, a cage, a partial or more than partial cone, or other suitable shape. Moreover, arms can extend from the ring to provide further support and orifices can be added to the support mechanism to increase or decrease flow characteristics.

Abstract: A passive flow control valve including a barrier member positioned in a fluid conduit between an upstream conduit portion and a downstream conduit portion. The barrier member substantially prevents fluid flow around a barrier member perimeter. The passive flow control valve also includes barrier member orifices extending through the barrier member, which allow controlled fluid flow through the barrier member orifices. When the fluid flows through the upstream conduit portion and encounters the barrier member, the fluid is prevented from passing around the barrier member perimeter and is forced to flow through the barrier member orifices.

Abstract: A diffused aeration method carried out in an aeration tank which contains a plurality of coarse bubble jet diffusers and a plurality of fine bubble jet diffusers strategically located to provide aeration in an inductive downward flow stream induced by the coarse bubble jet diffusers. The method increases oxygen transfer efficiency and mixing with little or no increase in operating power costs.

Abstract: A check valve having an upstream inlet part mountable on a discharge end of a conduit, a downstream outlet part adapted to prevent backflow of fluid through the check valve, and a transition part located between the upstream inlet part and the downstream outlet part. A longitudinal dimension of the downstream outlet part extending in a direction transverse to a direction of flow is at least approximately 1.57 times the diameter of the upstream inlet part.

Abstract: A diffused aeration system has an aeration tank which contains a plurality or peripheral coarse bubble jet diffusers and a plurality of fine bubble jet diffusers strategically located therebetween to provide maximum oxygen transfer efficiency and mixing with little or no increase in operating power costs.

Abstract: An air diffuser system contains a manifold and a plurality of elastomeric "duckbilled" check valves. The manifold is constructed from a conduit material and can be arranged in many different configurations. The valves are made from an elastomeric material, such as rubber, preventing the valves from being clogged with sludge, sediment, or other debris commonly found in waste treatment water. Additionally, the valves can be bored with predetermined orifice sizes, allowing the volume and pressure of escaping air to be determined prior to installation. To make installation of the valves easier, various types of coupling devices may be used to attach the valves to the manifold. Examples of coupling devices include restrictive orifices, "Y"-shaped conduits, and nipple conduits. Multiple valves can also be fabricated on a common cuff prior to installation.

Abstract: An asymmetrical check valve has an inlet end, a transition part and an outlet end, with a pair of vertical lips facing one another. The lips may be flat or they may be curvilinear. The check valve is asymmetric about a horizontal longitudinal plane through the check valve. The bottoms of the transition part and outlet end may be aligned, with a major portion of the lips extending above the horizontal plane. It is thus possible to install conventional or wide bill check valves in installations with little or no clearance between the outlet end and ground level.

Abstract: A tubular metal sleeve having two annular welding end collars and a flexible intermediate sleeve portion between the collars is mounted in a bore of a housing. The sleeve permits passage of high temperature pressurized fluids impervious to the sleeve. The sleeve forms part of a gauge for detecting the pressure of the fluid. A spacer may be mounted in a space formed between the sleeve and the housing to reduce the quantity of pressure-transmitting liquid required to fill the space.

Abstract: A tide gate valve has staggered pads embedded therein to provide sufficient strength to resist sagging and inversion, and to provide sufficient flexibility to promote an easy opening of the valve.

Abstract: An inversion-resistant tide gate valve includes a multiple-ply sleeve, and a rigid support member embedded therein to prevent the sleeve from sagging and to impart strength to the sleeve to prevent inversion.

Abstract: A deformable sleeve for a pinch valve includes an inner tubular body of elastically deformable material which is provided with flanges at its axial ends, and a mesh element having a tubular portion which surrounds the tubular body between the flanges and prevents the same from bulging out under the influence of internal pressure. The mesh element further has anchoring portions which are anchored to the flanges. The anchoring portions can either be connected to the faces of the flanges which face one another, or embedded in the material of the flanges, either directly, or by being connected, such as clamped between or welded to, anchoring rings which are embedded in the material of the flanges. The anchoring rings may be polygonal, especially rectangular or L-shaped in radial section, or circular or similarly curved in radial section. The mesh element may advantageously be of stainless steel mesh.

Abstract: A pinch valve sleeve for reducing the pressure of fluid flowing therethrough with or without actuation of the valve's pinching mechanism. The valve sleeve features an elongated hollow flexible resilient elastomeric sleeve body having an inner surface circumferentially bounding a flow-through passage and peripheral flanges at both ends suitable for attachment to a section of a pipeline or conduit system. The sleeve body has an ingress section adjacent to the inlet opening of the valve sleeve, an egress section at the outlet opening which permits fluid egress, and a pinchable intermediate section situated between the ingress and egress sections. The inner surface of the sleeve body has thereon a plurality of radially-extending, inwardly-directed protrusions operative for impeding fluid flow through the flow-through passage of the sleeve, thus reducing the pressure so that the pressure of the fluid which exits through the outlet opening is lower than the pressure of the fluid entering the inlet opening.