Abstract: An improved check valve is disclosed, which prevents the valve disk from slamming against the valve seat when the fluid flow in the line is suddenly reversed. The valve includes a disk and a seat, the disk being movable towards and away from the seat in response to pressure changes in the line. The disk, together with a central member, defines a chamber which becomes filled with fluid when the disk moves away from the seat. When the direction of flow in the line is suddenly reversed, causing the disk to move back towards the seat, the disk is cushioned by the fluid in the chamber, and does not slam against the seat. In one embodiment, an orifice is provided, spaced apart from the central bore of the valve, through which the fluid in the chamber can slowly and steadily leak out. In another embodiment, the orifice is provided in the disk of a pilot valve, which is a small check valve mounted at the inlet end of the main valve.

Abstract: An improved check valve is disclosed, which prevents the valve disk from slamming against the valve seat when the fluid flow in the line is suddenly reversed. The valve includes a disk and a seat, the disk being movable towards and away from the seat in response to pressure changes in the line. The disk, together with a central member, defines a chamber which becomes filled with fluid when the disk moves away from the seat. When the direction of flow in the line is suddenly reversed, causing the disk to move back towards the seat, the disk is cushioned by the fluid in the chamber, and does not slam against the seat. In one embodiment, an orifice is provided, spaced apart from the central bore of the valve, through which the fluid in the chamber can slowly and steadily leak out. In another embodiment, the orifice is provided in the disk of a pilot valve, which is a small check valve mounted at the inlet end of the main valve.

Abstract: A tensioning device for prestressing the rod members and transverse members connected thereto and operatively associated therewith has a jack assembly connected between at least two rod members and disposed to engage the transverse member, the jack assembly includes an expansion member such as a piston which can exert tensile forces incrementally on the rod members and the transverse member to evenly stress the same to a predetermined level. The tensioning device may have a pressure plate between the jack assembly and the transverse member to exert a more uniform pressure along the entire transverse member.

Abstract: A reciprocating plunger pump particularly adapted for the pumping of liquids has at least one pumping chamber and a plunger disposed for reciprocating movement therein, a common substantially integral inlet manifold for fluid to be pumped, a common integral outlet manifold for pumped fluid, and a valve assembly operatively associated and aligned with the pumping chamber and connected to the inlet manifold to receive the fluid to be pumped and to deliver the fluid to the pumping chamber, and operatively connected to the outlet manifold to pass the pumped fluid thereto. The valve assembly has cylindrical pressure containing parts including, a lower section, an intermediate section, and an upper section with a discharge passage extending end to end therethrough in the longitudinal axis of and in communication with the pumping chamber in the assembled position of the valve assembly.