Abstract: A conduit-break valve for a double conduit (10, 11) has a pressure relief device (28) with a pilot controlled check valve (41, 42) with a control piston (37) which is actuated by the pressure in the space (26) between the double conduits (10, 11) and opens the check valve (41, 42) when a limit value determined by the spring (43) thereof is exceeded. The check valve (41, 42) thereby relieves the pressure in a fluid lock which is formed by a piston and cylinder mechanism (17, 18) the cylinder (18) of which is normally kept closed by the check valve (41, 42) and the piston (17) of which is connected to the main valve member (16) of the main valve, whereby said valve member will be moved to closed position by the action of a pressure spring (19) when the check valve (41, 42) is opened.

Abstract: A safety connection located between a vessel containing a gas under pressure and a gas discharge system comprises a pilot controlled valve which is provided with a separate control system for opening the valve, the valve having a ball-and-socket system between the actuating rod and the valve-closing flap which it carries, so that the valve can also function as a sluice so as to avoid the need to provide a second pipe connected to the vessel and provided with a sluice as is conventional.The actuating rod of the valve carries a piston, one face of which is normally subject to the pressure of fluid in the vessel via the pilot valve but is connected to a vent as soon as an overpressure occurs, to open the valve. The other face of the piston is normally connected to a vent but is subject to the pressure of a fluid from an independent source of control fluid when the separate control system is operated to open the valve.

Abstract: An actuator head is provided for a pressure relief valve (1) having a valve element (11) spring biased to a closed position and arranged to be movable under the action of a fluid pressure medium in order to allow the escape of the fluid pressure medium through the valve for pressure relief purposes. The actuator head comprises an actuator (3) which is coupled with the valve element (11) and has a member (21) displaceable in response to fluid pressure applied thereto. A linkage (22, 19, 12) couples together the valve element (11) and the actuator (3) and has a lost-motion connection (72) which allows the valve element (11) to move against its spring biasing (13) for pressure relief purposes without imparting movement to the displaceable member (21) of the actuator (3). Biasing means (27) is arranged to oppose displacement of the displaceable member (21) of the actuator (3), and control means (4, 5) is provided to control the supply of fluid pressure to said displaceable member (21).

Abstract: An improved safety pressure relief valve which is particularly applicable to valves utilizing pressure taps for sensing the pressure within the inlet nozzle, such as pilot operated valves. The valve includes a valve body having an inlet opening into which a full nozzle is inserted. An annular port surrounds the periphery of the nozzle. An opening in the nozzle leading to the annular port provides for the insertion of a pilot or dipper tube therein. The valve body includes a channel leading between the annular port and an external tap for the pressure sensing line connected to the pilot control means. The design permits the nozzle to be rotated to any angular position with respect to the valve body, thus permitting ready assembly and disassembly of the valve. In a second embodiment, an annular port is used to permit direct injection of purging fluid into the nozzle to prevent its clogging.

Abstract: This device comprises a directional stage including a slide (30,32) of a directional valve, which slide carries a drain valve (34) and a valve of communication (36) with a vessel to be protected.The slide is controlled by the pressure in an intermediate cavity (42). A piloting stage comprises communication valves (48,50) for putting the cavity (42) of the directional valve in communication with the vessel and the drain (24) respectively under the differential action of an adjustable and calibrated system and of the pressure in the vessel. The system comprises a plurality of independently adjustable elements (62,70,72) which in particular modify the travels of the communication and drain valves (48 and 50).

Abstract: A self-pressurizing pinch valve is disclosed which is suitable for controlling the flow of liquid in a filling machine for dispensing predetermined quantities of liquid. The pinch valve comprises a flexible hose for conveying the liquid, a chamber defined about at least a portion of the flexible hose, the flexible hose being adapted to be pinched in the chamber for valving the flow of liquid therethrough, and a valve arrangement responsive to movement of the flexible hose for controlling the pressure in the chamber so that it substantially balances the internal pressure in the hose.

Abstract: A pilot operated relief valve for use on medium and high pressure vessels, conduits, and the like.A two-stage, non-flowing valve (5) operates a main relief valve (7) of substantially greater capacity. Flow control elements provided by (35), (36), (38), and (39) associated with the first stage poppet are utilized to provide positive valve operation. In a preferred embodiment the main valve is mounted directly onto the pressure vessel which is to be vented at a predetermined pressure. The pilot is preferably mounted closely adjacent to and in fluid communication with the main valve. A flow adapter (100) having a self-cleaning orifice is disposed intermediate said main valve head volume (68) and pilot vent port (1) to provide improved operation of the combination. A ball (16) selector, (24, 15, 76) provides means for conveniently connecting to a field testing either the pilot or the entire valve, providing improved setpoint and reset or blowdown adjustments for the overall combination.

Abstract: A pilot operated relief valve for use on medium and high pressure vessels, conduits, and the like. A unique two-stage, non-flowing pilot valve operates a main relief valve of substantially greater capacity. In a preferred embodiment main valve is mounted directly onto the pressure vessel which is to be vented at a predetermined pressure. The pilot is preferably mounted closely adjacent to the main valve for operating communication therewith. A particularly unique ball selector provides means for testing both first and second stages without operating the main valve, providing improved setpoint and reset or blowdown adjustments for the overall combination.

Abstract: A control system for regulating exhaust gas pressure in a furnace smokestack by means of three power cylinder actuated butterfly valves in the smokestack opening. An electronic control circuit provides digital output signals, which operate spool valve devices via which a hydraulic fluid circuit is established to control the power cylinders. In a trim mode control circuit, a first comparator senses a difference between the actual stack pressure and a desired pressure. The comparator output is converted by an analog to digital section to provide the digital output signals for control of a single butterfly valve. A rangefinder mode control circuit includes a second comparator that senses an output from the first comparator in excess of a predetermined value.

Abstract: A self-regulating tide gate is installed on a conduit connecting an open body of water with a protected body of water. The tide gate comprises a mounting plate secured to the conduit at its end in the open body of water, the mounting plate defining an opening into the conduit. A door has its upper edge pivotally mounted at the top of the conduit, a door float is mounted to the door on its edge opposite the hinged edge and counterfloats are mounted to counterfloat arms extending from the door across the pivot axis thereof. When the water is below a critical level at which it is desired that the door close, the door float maintains the lower edge of the door on the surface of the water, thereby maintaining the door open and blocking debris from jamming the mouth of the conduit. As the water level rises, it acts on the counterfloat to pivot the door towards its closed position, whereafter the door is caught in the flow of water entering the conduit and rapidly pivoted to its closed position.

Abstract: A hydraulically operated control arrangement for a transmission includes a spring-loaded pressure regulating valve which slides into a position to cut off an exit chamber for hydraulic fluid from an input chamber for pressurized hydraulic fluid so as to route the incoming hydraulic fluid exclusively to the transmission for various control and lubricating functions when hydraulic fluid pressure in the input chamber falls below a first threshold value. Hydraulic fluid applied to the input chamber continues to feed a first plurality of functions within the transmission via the input chamber and a second plurality of functions in the transmission via an intermediate chamber disposed between the input and exit chambers and in communication with the pressure regulating valve until such time as the hydraulic fluid pressure at the input chamber drops below a second threshold value so as to permit the pressure regulating valve to cut off the intermediate chamber from the input chamber.

Abstract: A pilot-operated back pressure regulator of simplified design and construction having a balanced valve plug attached to a diaphragm actuator and secured to the regulator body by bolts for ready simultaneous removal of the plug and actuator. The diaphragm divides the actuator into two cavities; a spring cavity acting to close the valve plug and pressure balancing cavity. A pilot valve is in communication with the inlet pressure to the regulator body, the spring cavity and an exhaust to regulate the inlet pressure to flex the diaphragm. In a preferred embodiment O-ring seals are located between (a) the valve plug and the valve seat, (b) the valve plug and its guide, and (c) the valve plug guide and the regulator body.

Abstract: A vacuum operated sewage system includes a static pressure sensor establishing a trigger signal at a selected first level in a standpipe. The sensor is connected upstream of a discharge control valve and actuates a trigger and timer controller at the selected sensed pressure to establish low for a predetermined period. A suitable time delay capacitor in the controller prevents transient signal actuation. A system pressure interlock senses the vacuum level of the system to disable the timer controller if system pressure is below a selected level. The interlock may include a pressure level control valve connected to bleed the capacitor and disable the timer controller. A system pressure sensing valve in parallel with the level control valve decouples the latter as long as the system level is above the selected minimum and thereby permits normal controller operation.

Abstract: A valve assembly comprises a valve body having a hollow and a valve element longitudinally movable between first and second positions therein. The valve assembly has at least one inlet and at least one outlet in pressure communicating relation to the hollow. The valve element in its first position blocks pressure communication between the inlet and the outlet. In its second position, the valve element permits pressure communication between the inlet and the outlet. A pressure sensitive indicator is operatively associated with the valve element. The assembly provides pressure communication between the inlet and the indicator when the valve element is in one of its positions and blocks such pressure communication in the other position. The assembly may also include other inlets and outlets, and the high pressure inlets are preferably longer than the respective controlling seals. Thus the seals need not cross the inlets to control flow therethrough.

Abstract: A pilot mechanism for a pressure regulating valve having a relatively high pressure inlet, a relatively low pressure outlet and main valve pressure responsive means for operating the main valve to control the pressure of the fluid downstream of the main valve. The pilot mechanism comprises pilot valve means for supplying a loading fluid to one side of the main valve pressure responsive means. A normally closed bleed leakage path is provided in communication with the loading fluid supplied to the main valve pressure responsive means for directing loading fluid away from the main valve pressure responsive means when the bleed path is opened. Second pressure responsive means are provided responsive to the pressure of the fluid to be controlled for controlling the position of the pilot valve means to in turn control the flow of loading fluid supplied to the main valve pressure responsive means.

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: A pressure relief valve of the diaphragm type having a condensate recovery device. The condensate recovery device is connected to the disc of the relief valve and provides means for moving condensate from an upper control chamber to either an inlet chamber or to a discharge chamber depending upon the relative pressures of the inlet and discharge chambers. Condensate from the control chamber enters a passageway in the recovery device through an inlet check valve and flows from the passageway through one of two inlet check valves into another chamber having a pressure higher than the pressure in the passageway. Each of the check valves includes a valve seat connected to one of the chambers and a ball which sits on the seat during the absence of any condensate in the passageway. Any condensate in the control chamber causes the ball at the inlet valve to float off the inlet seat and allows the condensate to enter the passageway.

Abstract: A safety valve actuator and pilot system for emergency closure of a flow line for fluids such as oil and gas including a hydraulic valve actuator connected on a valve in a flow line for opening and closing the valve, a pressure sensing pilot valve communicating with the flow line for directing operating fluid into the hydraulic actuator in response to a predetermined pressure change in the flow line, a closed fluid storage system connected with the hydraulic actuator for containing exhausted operating fluid and redirecting the fluid back into the flow line, and flow connections for operating the actuator to reopen the safety valve. One form of the system operates directly from flow line pressure for response to the predetermined high pressure. Another form of the system includes an operating fluid storage tank and functions in response to either a high or high and low pressure in the flow line.

Abstract: This invention relates to methods and apparatus for monitoring fluid pressure in a subsea petroleum installation or other similarly inaccessible system while isolating the well fluid from the production control system. In one particular form of the invention, a body of secondary fluid is pressure-responsively coupled to but isolated from the oil or other primary fluid of interest by a piston, which subjects the secondary fluid to the pressure existing on the primary fluid. In addition, a measuring device is connected to the secondary fluid to derive an electrical signal representation of the pressure on the secondary fluid as a correlative indication of the wellhead or other pressure actually sought to be measured.

Abstract: A vacuum operated sewerage system includes a static pressure sensor establishing a trigger signal at selected first level in a standpipe. The sensor is connected upstream of a discharge control valve and actuates a timer at the selected sensed pressure. The timer is connected to actuate the discharge control valve after a suitable time delay to prevent transient signal actuation, and establish flow for a predetermined period. An air admission valve is connected in series with the sensor to the timer to actuate the timer if the system vacuum drops below a selected level in the same manner as an increased hydrostatic pressure. The sensor can be eliminated for separate air admission control directly in response to the vacuum condition of the line.

Abstract: A valve actuator and a pilot assembly which may be utilized either alone or with the actuator is responsive to control fluid pressure for moving an operative means of a valve between open and closed positions. The actuator has a housing defining a cylindrical bore therethrough and a shaft is carried in the housing which is engageable with the operative means. A piston is carried by one of the shaft and the housing and is sealingly slidable along the other of the shaft and the housing and is longitudinally movable within the cylindrical bore.The pilot assembly comprises a cylindrical housing having pilot means within the housing, the pilot means having valve seat means thereon. Normally free traveling spherical members are provided immediate the pilot means and define valve head means selectively sealingly engageable on the pilot means to open and close the pilot means to control fluid flow therethrough.

Abstract: A relay pilot regulator for use in combination with a main regulator in a gas distribution system, the gas distribution system including an inlet conduit supplying gas at an inlet pressure and an outlet conduit for delivering gas at a reduced outlet pressure, the main regulator including a main valve controlling gas flow from the inlet conduit to the outlet conduit and thereby also controlling the outlet pressure, a main regulator diaphragm mechanically linked to the main valve and a loading chamber the loading pressure in which acts on the main regulator diaphragm wherein the loading pressure positions the main regulator diaphragm and the main valve, the relay pilot regulator providing and controlling the loading pressure in the loading chamber.

Abstract: There is disclosed a self-actuated pilot-controlled pressure-responsive valve for fluid pressure systems wherein the main valve is arranged to be seated by the fluid pressure in the system and a normally balanced piston and cylinder assembly pulls the main valve from its seat in response to elevated system pressure in a spring-loaded, tandem pilot and stabilizing valve assembly which in turn establishes a driving pressure differential across the piston, with the initial unseating of the pilot valve occurring substantially independently of the stabilizing valve which thereafter closes to hold the pilot valve open until reduced system pressure is achieved. At this time, the tandem valves operate as one with the pilot valve closing and the stabilizing valve opening against a force derived from system pressure through a conduit having a metering orifice which effects a pressure drop in the tandem valve assembly which insures full and chatter-free operation until the main valve is again closed.

Abstract: A valve actuator and a pilot assembly responsive to control fluid pressure for moving an operative means of a valve. The actuator has a housing defining a cylindrical bore therethrough and a shaft is carried in the housing which is engagable with the operative means. A piston is carried by one of the shaft and the housing and is sealingly slidable along the other of the shaft and the housing and is longitudinally movable within the cylindrical bore. A plurality of piston chambers are companionly associated with the piston and is responsive to control of source fluid pressure within a pilot assembly to manipulate the piston.The pilot assembly comprises pilot means within the housing, having valve seat means thereon. Normally free traveling spherical members define valve head means selectively sealingly engagable on the pilot means to open and close the pilot means. A pilot spool permits selective movement of the spherical members to the immediate vicinity of the valve seat means of the pilot means.

Abstract: The scram valve has a closing piston which can be controlled by a pilot valve in a pressure medium supply line to the closing piston. The pilot valve has a control piston which is spring biased on one side and connected on the other side with the flow of medium in the outlet spigot of the scram valve. Thus, should the pressure in the outlet spigot drop, the control piston moves to open the pressure medium supply line to the closing piston. In addition, this supply line is connected at the upstream end to the scram valve casing upstream of the valve seat so that the pressure of the medium flowing through the scram valve aids in the closing of this valve.

Abstract: A pipe line has a check valve therein, operable by an actuator. The actuator is connected to be operated by fluid pressure from the pipe line, and is connected with the pipe line by a control circuit including valve means. A differential pressure valve is connected in the control circuit, and is constructed to sense a drop in pressure within the pipe line downstream of the control valve. Upon sensing such a pressure drop, the differential pressure valve is effective to cause connection of the actuator to pipe line pressure upstream of the check valve, whereby the latter is automatically closed.

Abstract: A pipeline shutoff control actuated by movement of a pressure responsive element connected to the pipeline and having a predetermined restraining force applied thereto, said restraining force adapted to release said element in response to a predetermined rate of pressure drop in said pipeline whereby to actuate said control.

Abstract: A high-low shutoff valve of the reciprocating ball type which does not vent fluid to atmosphere upon the closing of the valve in response to operation of either the high or low pressure pilot.

Abstract: A fluid pressure operated control apparatus comprising a casing having an inlet and outlet for the flow of fluid under pressure, a diaphragm mounted in the casing having opposite sides thereof responsive respectively to outlet fluid pressure and a regulating pressure and valve means actuated by the diaphragm in response to pressure variations on its opposite sides for regulating outlet fluid pressure. The diaphragm is comprised of a main layer incompatible with high temperature pure steam and a protective layer. The layers are separable to provide for a contaminant fluid therebetween. The valve trim, including the valve head and stem, a valve stem guide and valve guide bushing having a snap-on valve seat, are insertable into and removable from the casing as an assembly, thereby providing for quick change of the valve trim.

Abstract: A fluid pressure operated control apparatus comprising a casing having an inlet and outlet for the flow of fluid under pressure, a diaphragm mounted in the casing having opposite sides thereof responsive respectively to outlet fluid pressure and a regulating pressure and valve means actuated by the diaphragm in response to pressure variations on its opposite sides for regulating outlet fluid pressure. The diaphragm is comprised of a main layer incompatible with high temperature pure steam and a protective layer. The layers are separable to provide for a contaminant fluid therebetween. The valve trim, including the valve head and stem, a valve stem guide and valve guide bushing having a snap-on valve seat, are insertable into and removable from the casing as an assembly, thereby providing for quick change of the valve trim.

Abstract: An apparatus and method for controlling a fluid pressure actuated valve are provided whereby the valve inlet pressure and valve outlet pressure are applied to control and limit the valve outlet pressure and to substantially reduce the fluid pressure applied to the valve actuating means when the valve inlet pressure is below a preselected safe value.

Abstract: A pump check valve control apparatus includes a pump for delivering a fluid to a system. A valve between the pump and the system controls the delivery of the fluid to the system. A valve actuator, signalled by an actuator control, begins to open the valve when the pressure on the pump side of the valve substantially equals the system pressure. During the opening cycle of the valve, a substantially constant pressure is maintained in the system. The actuator control closes the valve so that flow through the valve ceases when the pressure differential across the valve is substantially zero.

Abstract: A vent and relief valve for a tank containing pressurized fluid such as oxygen or hydrogen characterized in that coaxial vent and relief valve members have interengaged seats to close the vent outlet of the valve, the vent valve member having actuating means associated therewith to disengage said seats to open communication between the interior of the tank and the vent outlet of the valve as during filling of the tank, and the relief valve member being actuated by fluid pressure in the tank exceeding a predetermined value to move said relief valve member to disengage said seats and thereby again establish communication between the interior of the tank and the vent outlet of the valve thus to vent excess fluid pressure.

Abstract: A large vacuum pump is connected through a vacuum line to the cow milking apparatus, and a vacuum regulator is employed to admit into the line the amount of ambient air necessary to maintain the line pressure (and thus the pressure at the milking apparatus) constant within very narrow limits. The vacuum regulator comprises an air valve to control the admission of ambient air, and which is itself controlled by a light bias spring (having a low spring rate) and an opposed diaphragm. One side of the diaphragm is subjected to pressure generally equal to line pressure, whereas the other side of the diaphragm is subjected to pressure of air within a stabilizing and regulating dome. Adjustable means responsive to the pressure differential between the dome and ambient are provided to admit into the dome sufficient air to maintain the dome pressure constant. Furthermore, means are provided to bleed air through the diaphragm, thus maintaining substantially constant the pressure drop thereacross.