A contoured check valve disc features a pivot portion and a check valve portion. The check valve portion is attached to the pivot portion, and has two sides, a first side to respond to the fluid flow in a first direction and move the check valve portion away from a fluid opening to the one or more open positions depending on the fluid flow to allow the fluid to flow through the fluid opening, and a second and opposing side to respond to fluid flow in an opposite direction through the fluid opening and move the check valve portion towards the fluid opening to the closed position to seal the fluid opening and stop fluid flow. The check valve portion a near-sloped portion formed nearest to the pivot portion, having a near-sloped contoured surface curving away from the pivot point to a first point of inflection with a first curvature, and a far-sloped portion formed farthest from the pivot portion, having a far-sloped contoured surface curving away from the point of inflection towards a farthest point away from the pivot portion with a second curvature that is less curved or bent than the first curvature, the near-sloped portion and the far-sloped portion combining to form a combined surface having a contoured pressure/force distribution on the first side to respond to the fluid flow and move the check valve portion away from the fluid opening.

An insert is provided for insertion through an opening in the surface of a conduit, the insert comprising an insert body having first and second open ends defining an axis of flow therebetween. The insert further comprises a valve flap connected to the insert body. The valve flap is moveable between a closed position in which it creates a closure, thereby preventing flow along said axis, and an open position in which the valve flap allows flow along the axis. The valve flap is arranged so that, when in the open position, it is substantially U-shaped in side cross-section and is oriented with respect to the insert body so that said U-shape arches over the axis of flow.

A passive isolation valve equipped with one or more nozzles configured to deliver a flow of gas to an area adjacent the valve seat so as to remove accumulated particulate material from the area of the valve adjacent the valve seat that otherwise may adversely affect closure of the valve in response to an energetic event.

An air admittance valve preventing mephitis overflow, having a main body with an air entry guide base defining an air entry guide; a pivot support; and a valve seat. A sealing valve group having a sealing valve body that defines a recess; a flexible member; a pivot housing; and a pivot. The valve seat is located about the air entry guide. The pivot is located in the pivot housing and the pivot support, and the pivot is located along, or adjacent to, the center of gravity of the sealing valve body. The flexible member is at least partially located in the recess and abuts the main body; and when the air admittance valve is closed, the sealing valve body abuts the valve seat.

An air admittance valve preventing mephitis overflow, having a main body with an air entry guide base defining an air entry guide; a pivot support; and a valve seat. A sealing valve group having a sealing valve body that defines a recess; a flexible member; a pivot housing; and a pivot. The valve seat is located about the air entry guide. The pivot is located in the pivot housing and the pivot support, and the pivot is located along, or adjacent to, the center of gravity of the sealing valve body. The flexible member is at least partially located in the recess and abuts the main body; and when the air admittance valve is closed, the sealing valve body abuts the valve seat.

The present disclosure is directed to a backwater valve assembly comprising a main valve body, a flapper sub-assembly, and a cap. The main valve body has an inner wall that can define a recess into which the flapper sub-assembly can be removably secured. The flapper sub-assembly includes at least one flapper element that can pivot between an open position, in which the flapper element allows fluid to flow through the backwater valve assembly, and a closed position, in which the flapper element prevents fluid from flowing in the opposite direction. The flapper sub-assembly can be removably coupled to the cap to allow the flapper sub-assembly and cap to be installed in or removed from the main valve body together as a unitary assembly.

A yield monitoring system for a grain harvester includes a large strike plate mounted on parallel four bar linkages. The strike plate intercepts a larger portion of the clean grain flow and is supported near the four corners to provide even translation and force transmission even if not struck in the center of the plate. The four bar linkages provide translational movement relative to a center load cell. An engagement bracket at the center of the strike plate includes a surface that is aligned perpendicularly to the sensing element of the load cell.

In a device for discharging tire sealing agent from a container which can be connected to a pressure source and to a tire valve, a check valve is provided in the connection to the pressure source and/or in the connection to the tire valve.

There is provided a powerless back-flow prevention apparatus comprising: a body having a sewage inlet at a front thereof, a sewage outlet at a rear thereof, and a length-wise sewage channel there between; a door pivotally coupled to the body at the rear thereof to open or close the outlet, wherein the door comprises: a number of floating members arranged spacedly with each other; and a guide disposed on the floating members to pivot upwards via the floating force to close the outlet, and to pivot downwards via a gravity in an absence of the sewage back-flow to open the outlet, and, then to guide the sewage from the outlet.

A clack valve assembly comprising: a valve seat comprising an opening; a bearing comprising a recess with a base, a mouth, and a pair of side walls between the base and the mouth; a lid comprising a lid plate and a shaft, the shaft being received in the recess of the bearing; and a shaft retaining member which closes the mouth of the recess in the bearing, thus retaining the shaft within the recess. The shaft and the lid plate are integrally formed elements of a single part. The shaft can rotate within the recess to enable the lid to rotate from a closed position in which the lid engages the valve seat and covers the opening, to an open position in which the lid lifts away from the valve seat enabling fluid to flow through the opening in the valve seat.