Abstract: Disclosed herein is a plumbing spout that has back flow protection. The spout positions a check valve vacuum breaker underneath the pull up knob in a plug assembly. The spout provides back flow protection even though it has no fluid control valve for controlling flow through to the spout outlet.

Abstract: A faucet includes a valve body having inlet conduits and an outlet. There is a valve control element within the valve body to control flow from the inlet conduits to the outlet. A vacuum breaker hub is mounted on the valve body and forms a chamber with the exterior of the valve body. The valve body outlet opens into the chamber. There is a vacuum breaker system on the hub which includes a plurality of openings in the hub communicating with the chamber. There is a flexible valve element on the inside of the hub which normally closes the openings. There are ribs within the chamber, extending inwardly from the hub which ribs are on opposite sides of the vacuum breaker openings to preclude the flow of fluid from the valve body outlet to the area of the chamber about the flexible valve element.

Abstract: A cartridge valve 116 includes a fixed disk 80 and a movable disk 118 mounted in a housing 66. A lever 46 extends through a major opening 72 axially located at one end of the valve 116. The lever 46 is attached to a coupler 130 for facilitating movement of the movable disk 118 relative to the fixed disk 80 to control the flow and temperature of water passing through the valve 116. A flexible valve 144 is attached to the coupler 130 and, in normal use of the valve 116, prevents holes 136 formed therethrough from communicating with a passage formed through the movable disk 118. Air from the environment surrounding the valve 116 can enter the major opening 72, and upon the occurrence of a negative pressure in the water supply, will flex the valve 144 to allow air to enter the supply line to negate the undesirable effects thereof. In another cartridge valve 160, holes 166 are formed through the side wall of the housing 66 to provide further air communication through the holes 136 of the coupler 130.

Abstract: A device that produces toroidal bubbles of gaseous fluid when operated in immersed relation to a body of liquid fluid. A first embodiment is operated by a person who blows into a first end of the device with a short burst of air, and a second embodiment is operated by a pneumatic pump that delivers a short burst of air to the first end. A normally closed valve such as a poppet valve is positioned on a second end of the device. The valve opens and closes very rapidly in response to the burst of air. Air escaping around the peripheral border of the valve creates a toroidal bubble that expands in volume as it approaches the surface of the liquid fluid; the effect is visually pleasing. The valve of the device may also be held in the mouth, eliminating the conduit. In additional embodiments, the source of gaseous fluid is any pneumatically-charged device.

Abstract: A cartridge valve 116 includes a fixed disk 80 and a movable disk 118 mounted in a housing 66. A lever 46 extends through a major opening 72 axially located at one end of the valve 116. The lever 46 is attached to a coupler 130 for facilitating movement of the movable disk 118 relative to the fixed disk 80 to control the flow and temperature of water passing through the valve 116. A flexible valve 144 is attached to the coupler 130 and, in normal use of the valve 116, prevents holes 136 formed therethrough from communicating with a passage formed through the movable disk 118. Air from the environment surrounding the valve 116 can enter the major opening 72, and upon the occurrence of a negative pressure in the water supply, will flex the valve 144 to allow air to enter the supply line to negate the undesirable effects thereof. In another cartridge valve 160, holes 166 are formed through the side wall of the housing 66 to provide further air communication through the holes 136 of the coupler 130.

Abstract: A reflux valve means for a fluid conduit (30) having a fluid outflow end, wherein the valve means includes a vacuum valve (10) intended for connection to a conduit branch (18) preferably to a top part or rising gradient of the conduit upstream of its outlet end. The valve (10) includes a valve housing (15, 16) provided with a passageway (20, 17, 19) which establishes communication between the atmosphere surrounding the valve and the conduit branch (18). The passageway includes a valve seat (12) and a valve plate (11) which can be moved into and out of sealing contact with the seat (12) under the influence of conduit pressure that is higher than atmospheric pressure. The valve plate (11) of the vacuum valve is constructed to be deformable elastically into and out of a generally dish shape when the valve is closed, under the influence of those pressure variations that normally occur in the fluid in the conduit branch.

Abstract: A vacuum breaker valve configured for clean in place capability is provided which includes a body having an internal passageway including a chamber, a valve member shiftable within the chamber, and a motive member positioned adjacent an upper end of the chamber for selectively displacing the valve member. The valve member closes the upper end of the chamber under backpressure to inhibit undesired discharge of the fluid in the chamber, while the motive member, such as a selectively shiftable plunger, serves to periodically displace the valve member away from the valve seat at the upper end of the chamber whereby fluid, such as a cleaning solution, may pass through the valve body and internally clean the vacuum breaker valve without the need for disassembly.

Abstract: A valve assembly which is suitable for backflow prevention in a stop cock having an inlet, a seat and an outlet. The valve assembly may be attachable to the stop cock and includes a valve body having at least one opening and also including a valve chamber and a valve seat. There is provided a balance tube in the valve body which communicates with the valve chamber which has one end engaged with the stop cock seat for sealing against the seat for prevention of flow of fluid from inlet to outlet, a piston located within the valve body and engageable with the valve seat, and biasing means operable to unseat the piston from the valve seat to enable the outlet to communicate with the valve body opening. In a further embodiment the valve assembly also includes a third seat in the handle and a valve member biased open by a spring against inlet pressure to allow atmosphere air to break a vacuum at the inlet.

Abstract: A valve for permitting fluid flow in a first desired direction and preventing fluid flow in a reverse direction. The valve includes a valve body having a rigid wall defining inlet and outlet openings at opposite ends thereof and a main flow passageway between the inlet and outlet openings. Secured to the rigid wall, so as to receive fluid entering the passageway through the inlet opening, is a tubular valve member of elastomeric material having upstream and downstream ends in fluid communication with one another. The tubular valve member is normally open to fluid flow but is yieldingly collapsible in response to downstream pressure increases to prevent fluid from passing therethrough. A ring is secured about the tubular valve member and is dimensioned to prevent the passage of the downstream end through the inlet opening in the event of a downstream pressure increase. The drain control valve may be employed in conjunction with a novel manifold for irrigation purposes.

Abstract: An anti-syphon valve comprises a base pipe having inlet and outlet legs and a valve seat, disposed at the top of the base pipe within a valve stem post, which can be rotated selectively to block the inlet leg (closed position) or open it (open position). A metering peg extends from the valve stem post into a receptacle in the valve seat. Inlet and outlet passages corresponding to the inlet and outlet legs are disposed above the seat, and a float located at the top of the inlet passage allows fluid flow from the inlet passage into the outlet passage in the open position while blocking fluid flow from the outlet passage to the inlet passage in the closed position. Vent passages are provided above the float to enable communication of the outlet passage to atmosphere in the closed position. A handle is provided on the valve stem post to selectively rotate the latter to place the valve in open or closed position.

Abstract: A valve with a backflow preventer has a valve housing with a fluid inlet, a main flow channel, and a fluid outlet formed therein. A valve element is provided in the valve housing to selectively actuate the valve. The valve element is rotatable between an open position in which a fluid flow path exists between the fluid inlet and the fluid outlet along the main flow channel and a closed position in which no fluid flow path exists between the fluid inlet and the fluid outlet. A chamber is formed in the valve housing in a position which is offset from the main flow channel. The chamber has an opening in fluid communication with the atmosphere, and a ball is provided in the interior of the chamber. The ball is movable between a first position in which the ball prevents fluid backflow from the fluid outlet to the fluid inlet and a second position in which the ball substantially blocks the opening in the chamber.

Abstract: A vacuum breaker is provided comprising a body member having an inlet and an outlet defined therein. A core insert member may be threadedly engaged within the body member having a chamber defined therein. A vent passage is defined within the body member to vent the outlet side of the device to atmosphere. A piston member is movably disposed within the chamber between an upper limit stop and a lower limit stop so as to variably restrict liquid passage through the device. At its lower limit stop, the piston essentially seals the inlet from the outlet while the vent passage vents the outlet to atmosphere. At its upper limit stop, the piston essentially seals the vent passage from the outlet. A drain passage is defined within the device generally between near the top portion of the chamber and the outlet so that liquid entrapped within the chamber above the piston member drains through this drain passage to the outlet side of the device during movement of the piston within the chamber.

Abstract: A fluid flow system (20) includes fluid inlet conduits for supplying fluid through a fluid flow path (86) as formed by a manifold (74) and a module (76). The fluid is directed through fluid flow path (86) to a flexible conduit (54) and to a fluid dispensing wand (36) whereat the fluid can be selectively dispensed in a stream or a spray. A linking passageway (102) is formed by manifold (74) and module (76) to couple selectively the pressure of a pressurized environment, such as atmospheric pressure, to fluid flow path (86). An umbrella valve (104) is located in linking passageway (102) and is responsive to the development of a negative pressure at the fluid supply and thereafter couples the pressure of the pressurized environment to fluid flow path (86). This action neutralizes the effects of the negative pressure and precludes the reverse flow of fluid within fluid flow system (20).

Abstract: A backflow preventing device located downstream of a water control member of a sanitary fitting comprises a casing defining a cavity which communicates with a water feeding pipe and with an air inlet. Two shutting members are serially mounted and displaceable under the effect of a depression in the water feeding pipe, thereby connecting the water feeding pipe with the open air through the cavity. The two shutting members are composed of deformable membranes having different characteristics. One membrane is thin, supple and is umbrella-shaped, the other is thick and has the shape of a disc.

Abstract: An improved vaginal cleansing device comprising a T-shaped coupling, a first valve, a venturi, a second valve, concentrate reservoir, a solution delivery tube, and an applicator nozzle. The T-shaped coupling is interposed between a water source line and a shower head and diverts water to the first valve. The first valve controls the flow of water through the cleansing device and, when open, delivers water to the venturi. The venturi drafts concentrate from the concentrate reservoir under the control of the second valve and delivers either water or a mixture of water and concentrate to the solution delivery tube, and the solution delivery tube delivers the water or mixture to the applicator nozzle.

Abstract: Apparatus for diverting backflow includes a housing having first and second pressure openings for receiving fluid signals representative of first and second pressures. The housing has a gas inlet and a gas outlet and is formed with a gas transmission passage for carrying gas from the gas inlet to the gas outlet. The housing has a vent passage communicating with the gas passage and the region outside the vent passage for carrying fluid from the gas passage to the region outside said housing. Valve structure movable in the housing is responsive to the difference in pressures at the first and second pressure openings for blocking fluid flow between the gas passage and the vent passage when the pressure difference is greater than a predetermined value and allowing fluid flow from the gas passage to the vent passage when the pressure difference is below a predetermined value.

Abstract: A backflow preventer used in combination with a valve that normally supplies water under pressure to a feed conduit and with an outlet device having a supply hose to which water is normally supplied under pressure has a housing forming a generally closed chamber and formed with an inlet port connected with the feed conduit and opening into the chamber, an outlet port connected to the hose and opening into the chamber directly underneath the inlet port, and a vent port having an outside exposed to ambient air and forming substantially the only direct passage between the chamber and an ambient atmosphere around the housing. A check valve in the vent port only permits flow through the port into the chamber so that air can be drawn into the chamber through the vent port when pressure in the chamber is below ambient pressure. A nozzle fitted to the inlet port directed downward along a vertical axis into the outlet port forms therewith a jet pump for transferring water from the inlet port to the outlet port.

Abstract: An anti-siphon drain conduit. First and second cylindrical tubular portions with a U-shaped tubular portion interposed therebetween, and communicating with, the first and second cylindrical tubular portions. A drain passage extends through the conjoined tubular portions. A siphon break passage communicates with the drain passage at approximately the intersection of one of the cylindrical tubular portion and the U-shaped portion. A flap valve is formed integrally with at least one of the tubular portions for closing the siphon break passage upon the presence of liquid flowing through the drain passage. A bleeder cap is fitted to the siphon break passage. The bleeder cap has a dome portion penetrated by an aperture and an accordion portion. The bleeder cap serves freely to admit atmospheric pressure therethrough while tending to restrict any liquid that inadvertently enters the siphon break from exiting the siphon passage into atmosphere.

Abstract: A faucet with a pull-out spray head includes a mixing valve for combining water from hot and cold supply lines. Water from the mixing valve flows through a check valve assembly having a chamber with an inlet, connected to the mixing valve, and an outlet, that is connected to the spray head. Separate check valves are located in the inlet and the outlet to restrict water flow through the check valve assembly to only the direction from the inlet to the outlet. A hose connects the intermediate chamber of the check valve mechanism to a vacuum breaker adapted to mount next to the faucet. The vacuum breaker includes a housing with an internal cavity into which the conduit communicates. An aperture in the vacuum breaker housing provides a passage between the cavity and the ambient environment of the faucet.

Abstract: A ball cock for a flush tank having a valve chamber connected with a discharge chamber. A float operated piston valve is mounted in the valve chamber to control water flow to the discharge chamber. A hush tube connected to the discharge chamber feeds the water to the bottom of the flush tank. A combined volume control and anti-siphon valve is mounted in the discharge chamber between the inlet and hush tube to regulate the rate of flow and to act as a vacuum break under conditions of negative pressure in the water supply line.

Abstract: A food pasteurization system includes a vacuum breaker valve having a valve element in an axial passageway normally maintained in a closed, raised position by a coil spring on the top side of the valve. Multi-purpose drain and air openings are provided in the valve body and are positioned below the upper end of the valve passageway such that material moving upwardly through the valve is automatically drained out of the valve rather than back into the food conduit.

Abstract: An automatic air valve for a conduit, through which passes fluids and/or solids, which valve prevents the discharge of contaminated air therefrom into the environment and which further permits the introduction of fresh air from the environment into the conduit when a negative pressure develops therein. The valves may be disposed at either the terminus of or interposed within the conduit flow line of a duct system. The valves include an interior filter that restrains foreign objects, such as insects and snakes, in the duct systems from operatively interfering with the proper operation of the valve.

Abstract: A hydraulic faucet intended to house a cartridge containing flux control members shaped as plane plates of hard material, and comprising a valve body and a removable cover, wherein some inlet passages for ambient air are provided for in register with the faucet cover, and a one-way valve with elastic lip is housed within the cover, between an outer region of the faucet, communicating through the inlet passages with the outside ambient, and an inner region of the faucet, communicating with the delivery outlet of the faucet. This one way valve with elastic lip is inserted in such sense that it remains sealingly closed when the pressure in the inner region of the faucet is not lower than the ambient air pressure which is present in the outer region of the faucet, and it automatically opens when the pressure in the inner region of the faucet decreases, even of a slight amount, under the ambient air pressure, so that no siphon back flow may arise.

Abstract: A seal for a fitting adapter for fluid couplings wherein a coupling probe is received within a recess within the other coupling half and the seal prevents the creation of subatmospheric pressures during withdrawal of the probe. The seal includes a lip or flapper valve component which establishes sealing during coupling pressurization, and permits atmospheric pressure to flow around the lip during coupling disconnection.

Abstract: In a submerged pump system for pumping liquid from a well or vessel the vertical pipe through which the liquid is pumped by a submerged impeller pump is typically fitted at its upper end with an air valve. The air valve vents air from the pipe to atmosphere upon pump start up, then closes so that only water passes through a check valve to a pipe system and subsequently allows air to re-enter the pipe when the pump stops. A special throttling valve associated with the air valve restricts the outward rate of flow of air to atmosphere to thereby reduce the rate of the rising liquid and thus the shock of this liquid on the air valve and on the check valve but allows essentially unrestricted re-entry of atmospheric air to thereby allow the vertical pipe to fill with air rapidly. One form of throttling valve includes a valve plug mounted for axial movement into and out of a vent opening and spring-biased into the opening.

Abstract: A drain vent apparatus for recreational vehicles may be coupled to the drain vent of a drain line of a vehicle and includes a coupling for a drain hose for the output of the drain vent. The drain vent has an outer housing and an inner pipe located in said outer housing and connected to the coupling for the drain vent for coupling to a drain line of a vehicle. The outer housing forms an annular passageway around the inner pipe for the passage of air and a check valve is located in the outer housing passageway to allow the passage of air in one direction while blocking the passage of water in the opposite direction so that the outside vent air may pass into the drain vent to vent the drain line. The outer housing has an opening to atmosphere covered by a cap. The check valve may be mounted adjacent to the opening in the passageway adjacent the cap so that removal of the cap allows access to the check valve.

Abstract: A faucet valve 10 includes a ball valve 28 seated in a valve chamber 18. The ball valve 28 has a plurality of apertures 46 circumferentially spaced about the control stem 32 which extends through an opening 60 in the cap assembly 48 of the valve housing 16. A check valve 66 is formed within the hollow interior 62 of the ball valve and includes a disc section 70 that mounts a flap valve 78. A shield formed by a cylindrical wall 80 downwardly depending from the disc section 70 and a snap ring 84 fitted on the lower end of the cylindrical wall protects the flap valve from undue water turbulence. Negative pressure in the supply inlet opens the flap valve 78 to draw air through passageway 64 formed by the apertures 46 and auxiliary opening 60 and hollow interior 62 of the ball valve seated in the valve chamber 18.

Abstract: For use in pressurized fluid lines, an anti-siphon and back-flow prevention valve. A conduit is tapped into the line upstream of an outlet terminating in a ball-shaped housing. The housing receives check valve means arranged for insuring that fluid does not escape during normal operation of the line, but for admitting vacuum-breaking air in the event of line pressure loss.

Abstract: A faucet valve 10 includes a ball valve 28 seated in a valve chamber 18. The ball valve 28 has a plurality of apertures 46 circumferentially spaced about the control stem 32 which extends through an opening 60 in the cap assembly 48 of the valve housing 16. A check valve 66 is formed within the hollow interior 62 of the ball valve and includes a disc section 70 that mounts a flap valve 78. A shield formed by a cylindrical wall 80 downwardly depending from the disc section 70 and a snap ring 84 fitted on the lower end of the cylindrical wall protects the flap valve from undue water turbulence. Negative pressure in the supply inlet opens the flap valve 78 to draw air through passageway 64 formed by the apertures 46 and auxiliary opening 60 and hollow interior 62 of the ball valve seated in the valve chamber 18.

Abstract: A vacuum breaker for connection in the discharge line from a source of liquid. The preferred embodiment comprises an elongated body for connection in the discharge line and opening to atmosphere through a lateral passageway selectively closed by a cylindrical sleeve coaxially carried by said body. In the open position of the sleeve the vacuum breaker is particularly adapted for in-line installation in the drain line of appliances. Various applications for the vacuum breaker are disclosed.

Abstract: Disclosed is an air volume control for use with a flowing water line to control the quantity of air sucked by venturi action into the water line. The air volume control comprises a tubular valve body with a common member defining co-axial oppositely directed valve seats, one seat of which is automatically closed by a float valve in the event of reverse flow of water or back pressure of air into the valve body and the other seat of which is closed by a control valve when a regulator knob is rotated clockwise to the "off" position. In rotating the regulator knob counterclockwise to its "on" position, a cross pin follower of the regulator knob engaged with cam surfaces of the control valve unseats the control valve from its valve seat. Air is sucked into the water line through air entry ports in the valve body that are upstream of the control valve and float valve. Closing of either the control valve or float valve close off such air being sucked downstream past the valve seats into the flowing water line.

Abstract: A flushometer valve integrable with a structure to which it is mounted.

Abstract: A venting device for sanitary conduits comprising a first edge 12 and a second edge 10 bounding an air passage 7. One side of a valve 8 of flexible material is retained on the upper side of first edge 12, the other side provided with a downwardly extending ledge 13 moveably engages the top 15 of second edge 10. The valve 8 is provided with a thinned portion 9 near the first edge 12.

Abstract: A liquid flow control valve having a valve seat and a valve plug for engaging said valve seat, said plug being connected to a pressure responsive device, such as a diaphragm, for movement therewith, said control valve being opened and closed by forces acting on opposite sides of said diaphragm, an anti-syphon valve located below said diaphragm for directing air into said flow control valve when a suction occurs at the inlet to said valve seat; said anti-syphon valve comprising an annular array of flaps which control the flow of air through openings in the body of said liquid flow control valve. Said flaps can be arranged to also provide a barrier to reverse flow from the liquid flow control valve exit through said valve seat to its inlet. Said liquid flow control valve can be of the pilot valve operated type or manually operated.

Abstract: A drainage control valve apparatus utilizes a pressure relief valve for opening upon a predetermined fluid pressure being applied thereto and a liquid column is used for holding the pressure relief valve open by the weight of the liquid column escaping past the pressure relief valve to apply a negative pressure to the back of a pressure relief valve element. A small opening or a check valve releases the suction column when drainage is complete to allow the pressure relief valve to close. The pressure relief valve may be a spring biased valve and may be adjusted by varying the compression on the spring. The unit may be attached to a patient's leg with a strap. A method of draining a bladder is provided having the steps of opening a pressure relief valve under bladder pressure in a catheter, holding the pressure relief valve open with the suction of a column of liquid formed by the liquid passing the opened pressure relief valve and releasing the pressure relief valve when drainage is substantially complete.

Abstract: An anti-siphon selector valve for directing fluid into one of a plurality of lines. The valve includes a valve body having an input port and a plurality of output ports and a U-shaped conduit assembly mounted on the valve body and selectively connectable between the input port and one of the output ports. A movable piston is located in the conduit assembly for sealing the conduit to the valve body. The valve further includes an anti-siphon valve assembly mounted in the U-shaped conduit assembly for venting the output port and the lines to which it is connected to the atmosphere.

Abstract: An anti-siphon, selector valve for directing fluid into one of a plurality of lines. The valve includes a valve body having an input port and a plurality of output ports and a U-shaped conduit mounted on the valve body and selectively connectable between the input port and one of the output ports. The valve further includes an anti-siphon valve assembly mounted in the U-shaped conduit for venting the output port and the lines to which it is connected to the atmosphere.

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: Steam cleaning equipment comprising a water reservoir incorporating steam and water inlet ports and steam and water outlet ports arranged to supply steam at a controlled pressure and water in predetermined quantities to a hand piece where they are mixed in a venturi nozzle.A steam pressure reducing valve in the reservoir is immersed in the water and operated by steam pressure on a piston which has no sealing rings but which condenses steam leaking past the piston and passes the condensate into the reservoir.Detergent metering means and anti-siphon provisions are also described.

Abstract: A sequencing valve for distributing fluid from an inlet selectively to one or more of a plurality of outlets. The sequencing valve includes an inlet section, an intermediate section, and an outlet section; a piston valve arrangement controls flow from said inlet section to said intermediate section and a valving member directs flow from said intermediate section into a selected outlet or outlets of said outlet section; said outlet section including a biasing means for biasing said piston arrangement to a closed position; movement of said piston valve arrangement providing for sequencing of said valving member. Said biasing means (a) can provide a fixed biasing force on said piston arrangement; (b) can provide a positive closing force on said piston arrangement to prevent flow therethrough; or (c) can provide a negative force to reduce any closing force on said piston arrangement to zero. Said sequencing valve has a quick connect-disconnect type mechanism for providing easy access for inspection or repair.

Abstract: A distilling unit for distilling a sample wherein the distillate is passed in a closed system into a receiver, comprises a heatable distilling vessel, a spray or splash protection means, a condenser and a distillate discharge pipe which dips into liquid in the receiver. In order to ensure that, when the distilling operation is interrupted after a predetermined period of time, the liquid is not sucked back into the apparatus by the vacuum which is formed, the distillate discharge pipe has a non-return valve which vents the apparatus when there is the slightest reduced pressure. In this way, the conventional support plate no longer has to be lowered by expensive lifting means, as hitherto.

Abstract: A sequencing valve for distributing fluid from an inlet selectively to one or more of a plurality of outlets in response to pressure variation in the source fluid or fluid at other stations within the valve. The valve may be sequenced at the valve or remotely, is compact in construction, is configured to provide anti-siphoning protection, may be easily modified to accomplish several different modes of operation and various sequencing patterns, and is configured for easy maintenance of the various valving components.

Abstract: An automatic closure valve for water sprinkler which enables water from a water tap to be used without even necessity for stopping the tap and removing the sprinkler and water hose and enables water remaining in the hose and the closure valve to be automatically drained off after the water sprinkling, the closure valve being constructed with a valve casing, in which there are provided two valve chambers defined in mutual contiguity and communicated each other by means of a passage; a closure valve mechanism for closing the passage in response to increased pressure of water in the valve chambers; an opening which communicates the valve chambers and the external atmosphere; and a valve means which usually closes the opening by the water pressure, and opens the same when the pressure in the valve chambers becomes negative.

Abstract: A valved cap is provided for the top of a riser pipe connected to a flow line under pressure such as may be found in irrigation systems and is normally closed when the system is in operation. The valve automatically opens when the system is stopped to admit air for preventing a vacuum build up and closes under pressure when the system is started up during which time air in the riser pipe is permitted to escape to avoid a pressure build up while the valve is closing. An apertured fitting connected to the valve stem within the riser pipe connects to a flexible air vent hose extending down the riser pipe and into the main flow line in the direction of the flow and air trapped in the riser pipe after the valve is closed is siphoned through the hose into the main flow line to be expelled into the atmosphere at an outlet in the main line.

Abstract: An anti-siphon and back-flow prevention valve having a main valve chamber including air ports, an inlet at its lower end and an outlet at its upper end. Contained within the main valve chamber is a check valve including a check valve seat, through which the flow of liquid in the valve must pass. The check valve seat has a flexible diaphragm which mates with the check valve seat and functions to block any back flow of liquid from the main valve chamber into the inlet. A flexible ring is also contained in the main valve chamber and mates with the air ports to function as an air valve, allowing air to enter the main valve chamber during low pressure conditions down stream from the valve. The check valve and air valve operate independently of each other, responding to the various air and liquid pressures in and around the main valve chamber. Both valves are normally held closed by the force of gravity and static water pressure within the main valve chamber during no-flow conditions.