Abstract: A liquid supply system in which liquid is only supposed to flow from a high-pressure upstream portion to a low-pressure downstream portion is provided with a backflow preventer and upstream thereof with an isolating valve assembly. The backflow preventer opens completely whenever the pressure upstream of itself drops below a predetermined minimum, thereby draining the conduit downstream of itself to prevent reverse flow in the line. The isolating valve assembly continuously monitors the pressure in the upstream and downstream conduit portions and shuts a cutoff valve between these portions whenever the pressure differential between the two portions falls below a predetermined minimum, while simultaneously depressurizing or draining the downstream portion.

Abstract: An exhalation valve assembly for use in a volume ventilator circuit is disclosed. The valve assembly comprises a valve body defining a chamber with a gas inlet conduit and a gas outlet conduit, both in flow communication with the chamber. A diaphragm extends across the chamber and selectively closes off the gas inlet conduit. Upwardly extending strut members are disposed on an inside surface of the valve body and are used to position a removable ring member adjacent the diaphragm. The ring member is configured so as to support a portion of the diaphragm over the chamber.

Abstract: Methods and apparatus for controlling fluid flow wherein, according to the methods, a pressure-actuated main valve is conditioned to operate by fluid pressure actuation of a pilot valve, which closes a fluid flow passage through the main valve so that the main valve may then be actuated by fluid pressure. The apparatus is a self-piloting check valve apparatus, disclosed in three embodiments, wherein dual valves are provided. One of the valves serves as a pilot valve and is shown in the form of a spring-biased check valve, closing of which permits closing of a main ball valve adapted to withstand highly elevated pressures. The sealing elements of the valve are fully protected during flow periods whereby fluid erosion is prevented. Full opening flow passages are provided through the valves in each embodiment of the apparatus.

Abstract: A pressure-responsive valve unit is received in the cavity of a valve assembly housing, the inner end of the cavity being connected with a fluid container. The valve unit includes a main body having a chamber containing a check valve body that is movable toward and away from engagement with a valve seat on the main body, the valve seat facing the check valve body and the inlet end of the cavity, and the main body having passage means communicating fluid from the container to the front end portion of the check valve body. The check valve body is biased into engagement with the valve seat by a spring, the force of which is adjustable with a plug threaded into the inner end of the main body chamber. An outlet bore extends from the outer end of the main body to the valve seat, and the check valve body is engageable by a push rod inserted through said outlet bore.

Abstract: A reflux valve comprising a body having a passage communicating between an inlet and an outlet, a movable valve seat and closure member therefor within the body wherein the said valve seat is movable in a substantially axial direction.

Abstract: A check valve used in a fluid flow line is disclosed and includes a body having a first portion defining an inlet passageway, an outlet passageway and a shoulder which directs fluid flow upwardly through an opening into the outlet passageway and a second portion with a tubular section threadably engaged in the opening which receives the flowing fluid in one end for flowing up the tubular section and out outlet ports. A flange extends outwardly from the tubular portion at a location below the outlet ports to define an upwardly facing sealing surface. A plunger member is mounted within the body and includes a plug slideably mounted within the longitudinal passage and a tubular sleeve mounted to circumscribe the tubular section with the sleeve having a shoulder forming a downwardly facing sealing surface which is engageable with the upwardly facing sealing surface on the flange, the sleeve being moved upwardly by the pressure exerted by the fluid on the plug.

Abstract: An improved pressure regulator for an inflatable cuff on an endotracheal tube or the like includes a housing which contains a valve assembly and a pressure regulating chamber. The housing is adapted to be connected to an inflatable cuff so that the pressure regulating chamber communicates with the cuff through the valve assembly. The valve assembly (1) permits slow increases in air pressure in the cuff to be transferred into the pressure regulating chamber, thereby preventing over-inflation of the cuff, and (2) closes in response to relatively rapid pressure changes in the cuff to prevent collapsing of the cuff when the pressure of the air or other gas delivered through the endotracheal tube (e.g., by a respirator) is relatively high. A spring-biased piston is disposed in the pressure regulating chamber for regulating the pressure in an inflatable cuff to which the regulator housing is connected, and a rolling diaphragm covers the piston.

Abstract: An improved check valve is disclosed for use in a system for sequentially delivering primary and secondary solutions through a common conduit. The check valve comprises a hollow housing with an inlet and an outlet connected to an enlarged intermediate portion. Sealed at its periphery in the enlarged portion is a flexible diaphragm characterized by having foraminous means in at least its outer portion and imperforate means in its central portion. The imperforate means is spaced from a valve seat surrounding the passage at the inner end of the inlet so that when the primary solution flows from the inlet to the outlet, it will pass freely around the imperforate means and through the foraminous means. When an increase in pressure, even though slight, is exerted against the diaphragm caused by flow of the secondary solution in the direction of the outlet to the inlet, the diaphragm moves towards the inlet causing the imperforate means to seal against the valve seat and stop the flow of the primary solution.

Abstract: A check valve, especially for vacuum-operated installations in motor vehicles, which includes a two-partite housing and a roller diaphragm secured between the housing parts provided with inlet and outlet channels; the roller diaphragm which is pressed against its sealing seat by a prestressed spring, cooperates by means of its ring-shaped, curved diaphragm portion as movable sealing part with the bottom of one housing part constructed as sealing seat in such a manner that a central bore provided in the section of the roller diaphragm located on the side of the spring, connects the inlet channel terminating outside of the curved diaphragm portion with the outlet channel of the housing part, when the curved diaphragm portion lifts off from the sealing seat upon exceeding a predetermined differential pressure.

Abstract: A flow control valve assembly for controlling the flow of a working fluid which has a housing that defines a valve chamber therein, an inlet port to the valve chamber and an outlet port from the valve chamber, a valve body which is movably carried in the chamber between a closed position that blocks the outlet port from communication with the inlet port and an open position so that the inlet port is in communication with the outlet port to allow the working fluid to be forced through the valve chamber, and a valve control means responsive to the velocity of the working fluid flowing through the valve chamber or responsive to the pressure differential across the valve body to operate the valve assembly by moving the valve body between the open position and the closed position.

Abstract: A check valve assembly for use in a drill string to prevent reverse flow of drilling fluid through the string while permitting such fluid to be pumped downwardly through the well under normal conditions. The assembly includes: a valve body; a ball valve member, normally located out of the flow path in a side recess; a valve seat located above the valve member and means for controlling the rate of reverse flow of fluid required to move the valve member out of the side recess and against the valve seat.

Abstract: A well drilling tool including a tubular member having a bore therethrough and adapted for connection in a drilling string to form a flow passage for drilling fluid and a full opening rotatable ball type bore closure means pivotally mounted with the tubular member in the bore of the tubular member for enabling desired flow down the bore of the drill string and which automatically rotates closed when incipient well pressure conditions indicate the direction of flow in the bore may be reversed. The drilling tool includes a means for releasably locking the ball in the open position in response to a predetermined directional pressure in the bore to render inoperative the automatic operation of the ball. The drilling tool may be employed by stabbing the tool in a drilling string having an upwardly flow in the bore of the drilling string to connect the tool with the drilling string for subsequently blocking the upwardly flow.

Abstract: A valve apparatus adapted for connection in a drill stem comprises a sleeve member slidably guided in a body having a longitudinal fluid passage and lateral openings that communicate with an annular space surrounding the sleeve member. The sleeve member also comprises lateral holes of small diameter and bottom orifices or channels of large diameter. In a first position of the sleeve member, the fluid flows from the drill stem towards the annular space through the holes of small diameter. When the rate of flow reaches a sufficient value, the sleeve member is moved against a biasing spring to a second position, where the small holes are closed and the large channels permit the passage of the fluid through the valve, towards the lower part of the drill stem, without any noticeable pressure drop. The sleeve member is retained in the said second position through the pressures in the drill stem and in the annular space acting on different areas of the sleeve member.

Abstract: A check valve assembly for use in a drill string to limit reverse flow of drilling fluid through the string while permitting such fluid to be pumped freely into the well under normal conditions. The assembly may include: a valve body having a longitudinal flowbore therethrough; a valve seat at one end of the flowbore; a pair of inclined cylindrical recesses in the valve body communicating with the flowbore; and a ball member normally disposed in either one of the recesses and movable into the flowbore for sealing engagement with the seat in response to a predetermined rate of reverse flow through the flowbore.

Abstract: A fire valve having a cooperating valve seat and shiftable valve part. The valve part is carried by a floating valve stem. The first valve includes a piston and cylinder combination which is operatively associated with the valve stem and which causes the valve part to be selectively spaced from the valve seat in response to fluid pressure in the valve.

Abstract: A check valve assembly for use in a flow conductor. A tubular valve body with a central flow passage is mounted in the assembly. A spring urges the body toward closed position in which a rigid sleeve encircles and covers outlet ports in the downstream end of the body. A resilient skirt of rubber extending from the end of the sleeve engages the outer surface of the body to form a seal which prevents reverse fluid flow through the valve. The rigid sleeve isolates the ports from high reverse pressure differentials. Forward flow, or a sufficiently great forward pressure differential, overcomes the spring bias and pushes the downstream end of the tubular body through the bottom of the sleeve and skirt to a position in which the outlet ports are uncovered for normal flowing operation. The spring returns the valve body to closed position when the flow reverses or the forward pressure differential falls below a prescribed value.

Abstract: A drilling mud saver valve connected to the lower end of a kelly allows down flow of mud or other drilling fluid when pumps are actuated to circulate drilling fluid, but closes when the pumps are off, thereby retaining drilling fluid thereabove in the kelly to prevent loss of fluid when the kelly and valve are disconnected from the drill pipe.The valve includes a tubular body and a top sub screwed therein. A replaceable seat is carried by the lower end of the top sub. A poppet type valve closure is urged upwardly against the seat by a helical spring strong enough to close the valve against the weight of drilling mud in the kelly.The poppet valve closure has a central flow passage therethrough, communicating with the stem and controlled by an upwardly opening check valve, to communicate drill pipe pressure to the kelly when the pumps are off. The check valve closure is frangible for easy break out if wire line tools need to be run through the valve.

Abstract: A check valve has a body with a seat therein and a valve plug movable toward the seat to closed position and away from the seat to open position. The valve plug has a forward face facing toward the seat and body inlet and a rear face facing away from the seat and toward the body outlet. The plug, at its rear face, has a stem of smaller diameter than the rear face so that an annular area of the rear face of the plug is exposed rearwardly toward the body inlet. The stem has fins thereon of a shape to impede the return flow of fluid relative to the stem in a direction toward the seat and thereby assist in rapid closure of the valve. The rear face of the plug is concave rearwardly and slopes inwardly from its outer periphery toward its axis at a very slight angle to further assist in rapid closure, while reducing outward radial components of flow of return fluid.