Abstract: A control valve for dissipating the energy of a high pressure flowing media, the apparatus comprising a valve body having an internal cavity, an inlet and at least one outlet, the inlet, outlet and cavity being in communication to form a flow path through the body of the valve, a plurality of helical springs being arranged one within the other and disposed in the cavity with the convolutions of the innermost of the springs defining an axial fluid media pathway in open communication with the inlet, there being an actuator operable externally of the body for selectively effecting axial, reciprocal movement of the convolutions of the springs whereby the axial spacing between the convolutions of the springs is altered to control the fluid media flow from the pathway through the spaces between the convolutions to the outlet.

Abstract: A double disc gate valve of the type wherein discs are provided with wedge means which force the discs against substantially parallel opposed valve seats having at least one spherical surface between a wedge and a valve disc to allow the discs to have more freedom of movement to accommodate misalignment of the seats due to variation in manufacturing tolerances or pipe line distortion.

Abstract: A check valve of the type having a counterweight is provided wherein the counterweight is mounted on a shaft directly above the shaft carrying the valve disc, the counterweight being connected to the shaft carrying the valve disc by gearing. By mounting the counterweight above the valve disc, the valve does not require any additional width for installation and is thus adapted for installation in tight quarters.

Abstract: A feed water check valve of the swing type is provided with a soft seal backup to the main element to ensure sealing of the valve plug so that no leakage occurs during testing or when full closure is required as in an emergency.

Abstract: A combination reheater isolation device and chemical connector is provided which is particularly adapted for use on lines leading to and from the reheater in a boiler-turbine plant system wherein the device can be used under normal system working conditions as a normal T-type fitting, wherein it can be modified to accept a chemical connector attachment for use in chemical cleaning and flushing and wherein the device also serves as an isolation device for hydrotest purposes. The device of the present invention employs relatively few parts and these are rugged and easy to assemble and disassemble.

Abstract: A check valve construction is provided which is free of friction imparting elements such as a labyrinth seal or a stuffing box with internal packing having an external mounted counterweight. One embodiment is of the power assist type constructed with convenient means for local daily testing the free swing portion of the check valve while another embodiment includes a manual test device. The valves may include friction free disc position indicators.

Abstract: A valve structure is provided which can be opened and closed under operating conditions without any adjustment in conditions existing in the system in which the valve is an element. The valve element can be turned with respect to the seat to provide for proper relation between the valve element and the valve seat to grind one with respect to the other during the operating cycle. The valve also includes a clutch having a radial acting trip overload that prevents the valve seat from being damaged during grinding which is effected by turning the valve through the clutch while moving the valve toward the seat during the closing cycle and produces a controlled grinding operation independent of pressure within the valve.When the valve is operated in the opposite direction, the clutch disengages and the actuator mechanism encounters only the thrust forces during the opening cycle. This allows the valve to be easily opened without overloading the system.

Abstract: An in service exercisable tilt disc check valve is provided having an externally controlled power actuator connected to the valve shaft for moving the valve disc relative to the valve seat. The valve shaft has a radially extending tooth which is received in an elongated sector socket in the valve disc. As the shaft is rotated, the tooth engages the end shoulders of the socket and provides a connection between the shaft and valve disc. With the tooth positioned intermediate the socket ends, the valve disc is free to swing on the shaft.By selectively positioning the valve shaft, the valve disc may be forced to close against the valve seat to inspect the sealing integrity of the valve or the disc may be displaced from the valve seat to "exercise" the valve. The valve shaft may also be positioned to allow the valve disc to pivot normally as a check valve.

Abstract: Main steam isolation valves are required for both PWR and BWR nuclear steam supply systems. In the event of a main steam line rupture, these valves must prevent gross loss of steam. The pressure drop across the valves is a direct factor in the efficiency of the generating plant. The rate of steam flow through the valves is high. These conditions require large port diameter valves that are reliable, can close rapidly, have low pressure drops, and are suitable for operation at specified design pressure and temperature. The valve of the present invention includes a parallel seat, fully revolving, double disc gate valve and fully satisfies the above requirements. The valve of the present invention embodies a valve operating mechanism which is fully enclosed within the primary pressure containment of the valve. This precludes any part of the operator being damaged by missiles resulting from other system failures.