Free flow fitting
 A high pressure lubricant fitting or check valve comprises an internal retainer generally in the form of a parallelipiped to prevent spring deformation and undesired plugging off during use. An inlet connects to a high pressure grease source for introduction of grease through an inlet passageway axially aligned with a larger diameter outlet passageway. The passageways are separated by a valve seat. A rigid retainer threadably mounts within the outlet passageway and defines dual flow paths of similar dimension and configuration. A ball valve which selectively blocks the valve seat to control fluid flow is biased by a spring coaxially mounted upon a rigid stem emanating from the retainer. Fluid flow is established about the outer periphery of the valve ball and around the spring and through the dual flow paths. In response to inputted lubricants, the ball and spring are forcibly deflected downwardly and limited by the rigid stem. Even when the ball valve is compressed against the stem by several thousand pounds of pressure, a blocking seal cannot be formed by the spring or ball. The retainer is locked within the outlet passageway to prevent blowout. 
F F Y
F16K F16N Y10T
inventional inventional additional
James H.
Hill