Check valve for meter run

A fluid check valve for preventing back flow of fluid through a fluid conveying conduit, comprising:

• said check valve having a main body;
• an annular passageway through which flow can occur through said main body;
• said annular passageway lays along a central longitudinal axis and includes a throat, a working chamber, and an outlet;
• mount means including opposed upstream and downstream faces by which said check valve can be mounted with respect to a fluid conduit to enable flow to occur therethrough;
• said throat forms an entrance into the annular passageway at a location adjacent said upstream face, said throat is of a relatively small diameter that enlarges into said working chamber, and forms a lip at an upstream end thereof;
• said lip having opposed walls with an outer wall thereof coinciding with said upstream face and the opposed wall thereof enlarges into said working chamber;
• said working chamber terminates at a circumferentially extending locking groove having a diameter greater than the diameter of said working chamber;
• a valve element having an upstream and a downstream face, an annular seal means on said upstream face of said valve element;
• an annular seat formed within said working chamber adjacent the downstream side of said throat for receiving said seal means of said valve element in seated relationship therewith and thereby prevent backflow of fluid through said check valve;
• the upstream face of said valve element includes a curved face having a circumferientially extending edge and an apex intersected by the central longitudinal axis of the main body passageway;
• said seal means being formed on a marginal edge portion of said curved face for sealingly engaging said seat;
• a valve cage by which said valve element is captured within said working chamber for axial movement toward and away from said seat for engagement and retraction of said seal means with respect to said seat;
• said cage has a central body part affixed to a plurality of legs that radially extend therefrom and terminate in an outer rim;
• said outer rim is received within said locking groove, and thereby removably mounts said cage within said locking groove;
• biasing means for urging said valve element against said seat;
• said biasing means is a spring, an annular spring receiving cavity located on the downstream face of said valve element and concentrically arranged respective to said axial passageway and said valve element;
• whereby pressure differential across said valve element urges said valve element against said cage central body part with said spring being compressed into said spring receiving cavity while fluid flow occurs through a space defined by the inside diameter of the throat and the periphery of the valve element;
• whereby said valve element can move from an open position that abuts the cage central body part and into a closed position that abuts said seat.