Abstract: A check valve having a semi-spherical valve member movable longitudinally in a generally tubular housing between a closed position engaging a conical valve seat and an open position spaced longitudinally therefrom, the valve member being slidably mounted for such movement on a longitudinally extending support element. The opening in the valve member which receives the support therein has a diameter significantly greater than the diameter of the support element whereby the valve member is pivotal thereon so as to seat properly on the valve seat. The center of the semi-spherical valve member is longitudinally spaced in one direction from the effective center of support thereof at the closed position of the valve member, and is longitudinally spaced in the opposite direction from the effective center of the valve member at the open position of the valve.

Abstract: A blow-down safety valve having means for directing the fluids exiting therefrom along a flow path which assists the valve member to open and seat quickly without excessive bleeding. The valve member includes a flat seating portion and an annular lip extending perpendicularly thereto to change the direction of the exiting fluid flow and direct it downwardly along the exterior wall of the valve inlet conduit, and a blow-down ring is provided to form an annular huddling chamber for receiving and collecting such downwardly directed fluid. The annular huddling chamber includes a bottom wall beneath the valve member annular lip and a side wall extending upwardly from the bottom wall toward and beyond the annular lip and in spaced relation thereto for directing fluid flow from the annular huddling chamber along a path substantially opposite to the direction of fluid flow into the huddling chamber.

Abstract: A safety valve for use in gaseous service at elevated temperatures, including a casing provided with an annular valve seat and a selectively moveable valve member having mounted thereon a plastic annular sealing ring for seating on the valve seat. The plastic annular sealing ring is preferably formed of Teflon P.F.A. fluorocarbon and is shrunk fit onto a projecting shoulder portion of a metal seal retainer detachably mounted on the valve member, and the valve seat includes a projecting ridge formed by intersecting flat surface portions disposed at an obtuse angle to one another, whereby the plastic annular sealing ring will be engaged by the valve seat ridge when the valve member is seated.