Abstract: A gas flow arrestor is provided that is configured to be coupled at one end to an oxygen concentrator, a VIPR type device associated with a compressed gas cylinder, or other gas delivery component such as a regulator or flowmeter and at the opposing end to a length of flexible tubing or hose that delivers the medical gas to the patient or patient breathing apparatus, such as a nasal cannula or breathing mask. The gas flow arrestor device includes a firebreak together with a visual flow indicator that is actuated by the flow of gas through the gas flow arrestor device. The visual flow indicator allows a user or patient to visually confirm from a distance whether or not gas is flowing to the patient or breathing apparatus.

Abstract: An inflator including in combination an inflator body having at one end an input for receiving the neck of a gas cartridge, a manifold assembly intended to be fluidly connected to an inflatable, a combination automatic and manual actuator assembly including a spring-loaded actuator including a pierce pin for fracturing a frangible seal of the gas cartridge, a bobbin with a dissolvable pill that retains the spring-loaded actuator in a cocked position and a hood connected onto the end of the inflator body, said hood including an inwardly-extending tab that engages the actuator to securely retain the hood onto the end of the inflator body by means of the inwardly-extending tab being grasped by the forked end of the actuator.

Abstract: A Liquid Flow Indicator Device comprising: a sight glass having one or more cages positioned around the sight glass for containing one or more indicator objects, so a user can see the indicator objects, which are visible to the user looking through the sight glass, thereby providing visual notification to the user. When the liquid is flowing through the cages and also the sight glass, the indicator objects will float around inside the cage, thereby providing visual notification to the user that the liquid is flowing through the cage and the sight glass. The indicator objects can also make a sound when the liquid flows through the sight glass and through the cage by banging around inside the cage, thereby providing audio notification to the user that the liquid is flowing through the sight glass. As such, this invention provides Audio notifications and/or Visual notifications regarding the flow of liquid. A fluid transport system and a method of using the device.

Abstract: A gas flowmeter and associated method of forming a glass flowmeter includes a body having a passage that communicates with an inlet and an outlet for receiving gas flow therethrough. A selectively variable valve controls a flow of gas to the outlet, and plural calibrated scales are operatively associated with the passage to represent a flow rate of gas through the passage. First and second floats having different material properties are received in the passage and are viewable in operative association with the calibrated scales.

Abstract: A gas flow indicator apparatus (10) comprising: a gas flow chamber including at least one transparent portion (30) and at least one opaque portion (36); at least one inlet port (34); at least one outlet port (32); and, at least one gas flow signal means (18) movably disposed within the gas flow chamber. The gas flow indicator apparatus (10) being configured such that when no gas flow is present and/or when a predetermined gas flow rate has not been achieved, the signal means (18) is disposed substantially within one of the transparent portion (30) or the opaque portion (36), and wherein when gas flow is present and/or the predetermined gas flow rate has been achieved, the signal means (18) is moved to be disposed substantially within the other of the transparent portion (30) or the opaque portion (36). Gas delivery devices (12), systems (12) and/or conduits (16) incorporating the gas flow indicator apparatus (10) are also provided in accordance with the invention.

Abstract: A stage light fixture is provided with a light source and with a cooling assembly configured to cool the light source; the cooling assembly comprises at least one cooling device configured to generate a flow of cooling air through an outlet opening having an elongated shape along a main axis.

Abstract: Systems and indicators of cleaning effectiveness are provided for deployment in an environment where samples of different vacuum cleaners are displayed for consideration by potential purchasers or renters of such vacuum cleaners to facilitate comparisons of cleaning effectiveness between or among the different vacuum cleaners.

Abstract: An air flow sensor includes a case, a to-be-detected object, and a detector. The case includes an intake port and an exit port through which air is to flow. The to-be-detected object is located at a first position in the case when the air flowing from the intake port to the exit port has lower than a predetermined level of pressure, and is movable from the first position receiving the air when the air has equal to or higher than the predetermined level of pressure. The detector is disposed outside the case and is configured to detect a movement of the to-be-detected object and output an electrical signal.

Abstract: An attitude sensing arrangement for triggering a shutoff mechanism on a fuel dispensing nozzle comprising a rolling element placed inside a non-cylindrical chamber that is sealed with a plug such that the rolling element may move freely inside the chamber. A vacuum sensing path passes from a sensing port in the nozzle spout, through a vacuum sensing tube, into the non-cylindrical chamber, and into a venturi-generated vacuum chamber. The attitude sensing arrangement is configured such that the rolling element blocks a shutoff port in the non-cylindrical chamber when the nozzle is raised past a certain shutoff angle. When the vacuum sensing path is blocked by the rolling element in this manner, the shutoff mechanism closes the main fuel valve.

Abstract: A fluid-pressure indicator includes a housing having a first region and a second region. A pressure-responsive member is disposed in the first region and is movable between an expanded state and a compressed state. An indicator disk is viewable through the pressure-responsive member when the pressure-responsive member is in the compressed state and is obscured from view through the pressure-responsive member when the pressure-responsive member is in the expanded state. A diaphragm is movable from a relaxed state to a deflected state in response to pressure within the second region exceeding a threshold pressure and prevents fluid communication between the first region and the second region. The diaphragm additionally causes the pressure-responsive member to move from the expanded state to the compressed state when the pressure exceeds the threshold pressure.

Abstract: A pipe direction and size indicator which may be attached to a pipe inspection camera for use in determining the flow direction and size of a pipe. The pipe direction and size indicator generally includes an adapter member, extension member and indicator member. The adapter member is adapted to be removably attached to a camera. The extension member is removably secured to the adapter member by a threaded connection. The outer end of the extension member includes an indicator member which is attached thereto and allows the indicator member to freely rotate, swivel and move about the extension member. By observing the positioning of the indicator member, which will be freely affected by gravity, an operator of the present invention may determine the directional flow of a pipe being inspected. Further, by accounting for the size of the indicator member, the size of the pipe may also be determined.

Abstract: A fluid flow indicator for observation of low flow rates in liquids includes a capillary tube (12) slidably mounted at each end in passageways (4) and (5) and biased into a no-flow indicating position by a castellated elastomeric membrane (14) providing a sealed barrier within a chamber (1) between a first zone (17) and a second zone (18). Fluid flow introduced through spigot (9) causes the capillary tube (12) to slide to the opposite end of the passageways (4) and (5) whereupon the deformed position of the elastomeric membrane (14) can readily be observed through transparent walls (3) in the chamber (1). Upon cessation of flow, the elastomeric membrane (14) causes the capillary tube (12) to revert to its original position.

Abstract: An indicator suitable for signaling restricted flow of a fluid through a filter mounted in a filter indicator includes a housing having an inner cavity. A diaphragm disposed within the housing separates the inner cavity into first and second chambers and deflects from a neutral position in response to applied pressures within the first and second chambers. A tab assembly opposite the diaphragm includes a spring-loaded flag moveable from a first position within the housing to a second position outside the housing. A pin operably coupled to the diaphragm holds the spring-loaded flag within the housing when the diaphragm is in the neutral position. In response to the diaphragm being deflected sufficiently from the neutral position to release the pin, the spring-loaded flag travels to the second position outside of the housing, thereby indicating a restrictive flow condition for the filter.

Abstract: The present disclosure relates to a restriction indicator for an air cleaner system of an internal combustion engine. The restriction indicator includes a housing divided into first and second chambers by a diaphragm. A signal member is connected to the diaphragm. The signal member is moveable along an axis between a reset position and a first indicator position, and defines an axial opening within which a first retaining shoulder is located. A guide member is provided for guiding the signal member as the signal member is moved between the reset position and the first axial position. A retaining member is provided for retaining the signal member in the first indicator position. The retaining member extends within the axial opening of the signal member and includes at least two fingers that project radially outward from the axis. The fingers are configured to engage the first retaining shoulder to retain the signal member in the first indicator position.

Abstract: A filter cartridge end-of-life mechanism and a filter cartridge assembly for a water treatment device. The end-of-life mechanism comprises a float which is moved along an escapement path each time the device is filled. A counting mechanism connected to the float provides a continuous visual indication of the amount of useful life remaining in the filter cartridge. The cartridge assembly includes a tray detachably connected to a filter cartridge. The tray is positioned beneath the outlet end of the cartridge to remove water treatment particles from the treated water.

Abstract: A filter cartridge end-of-life mechanism and a filter cartridge assembly for a water treatment device. The end-of-life mechanism comprises a float which is moved along an escapement path each time the device is filled. A counting mechanism connected to the float provides a continuous visual indication of the amount of useful life remaining in the filter cartridge. The cartridge assembly includes a tray detachably connected to a filter cartridge. The tray is positioned beneath the outlet end of the cartridge to remove water treatment particles from the treated water.

Abstract: The present disclosure relates to a restriction indicator for an air cleaner system of an internal combustion engine. The restriction indicator includes a housing divided into first and second chambers by a diaphragm. A signal member is connected to the diaphragm. The signal member is moveable along an axis between a reset position and a first indicator position, and defines an axial opening within which a first retaining shoulder is located. A guide member is provided for guiding the signal member as the signal member is moved between the reset position and the first axial position. A retaining member is provided for retaining the signal member in the first indicator position. The retaining member extends within the axial opening of the signal member and includes at least two fingers that project radially outward from the axis. The fingers are configured to engage the first retaining shoulder to retain the signal member in the first indicator position.

Abstract: An oxygen delivery system which provides a visual and audible warning signal for system or oxygen flow failure. When pressure fitted tubing detaches, the audible whistle alarm indicates that the oxygen delivery system has become disconnected and the system has failed. An audible alarm signals that the oxygen delivery system has failed. A clear acrylic ball, located at the device's central area, contains a fan. The fan is mounted so that it turns in response to oxygen flow. The turning fan has blades which are color coded to visually indicate the delivery rate of oxygen to a patient. An anti-reflux mechanism, located at the proximal end of the device assures the elimination of back-flow pathogens into re-usable permanent equipment.

Abstract: A paddle type flow detector for an explosive environment is mountable onto a pipe. The detector includes a structure for mounting to a pipe, a substantially sealed switch housing containing an electrical switch, and a paddle located within the pipe. A lever mechanism connects to the paddle and extends up through the mounting structure and to the switch housing. A spring is contained between the switch housing and the mounting structure and is connected between the lever mechanism and a screw adjustable spring block. The spring is contained within a spring compartment formed between the switch conduit and the mounting structure. A slide rod is operatively connected to the lever mechanism and to the switch to change a state of the switch upon sliding movement of the slide rod. The slide rod is tightly fit within a bore of the switch housing and blocks a flame path between the switch housing and the spring compartment.

Abstract: A control apparatus for a liquid medium including a body portion provided with flow channels. The body portion includes an inlet for the medium, an outlet for the medium to an apparatus that the medium is conducted to, a return point for the medium returning from the apparatus, and a discharge point through which the medium is discharged from the control apparatus. A flow control valve and flow and pressure measuring devices are arranged after the medium inlet in the flow channels of the body portion. A pressure control valve for controlling the pressure in the flow channels between the flow control valve and the pressure control valve is arranged after the return point. For safety reasons, a pressure relief valve is arranged in the channel system of the body portion provided by the flow channels between the flow control valve and the pressure control valve, the relief valve being arranged to open as the pressure exceeds a certain allowed value.

Abstract: The height of the valve with a flow meter shall be as small as possible, enabling it to be mounted in restricted spaces. In order to achieve this, all adjusting and display movements are not executed axial but on the contrary polar. The rotating spindle of the valve is designed as rotary slide valve and the display marker or the graduation of the display unit of the flow rate meter is present on a rotating bush. The total height of the valve with a flow meter is accordingly low and unchangeable.

Abstract: A filter cartridge end-of-life mechanism and a filter cartridge assembly for a water treatment device. The end-of-life mechanism comprises a float which is moved along an escapement path each time the device is filled. A counting mechanism connected to the float provides a continuous visual indication of the amount of useful life remaining in the filter cartridge. The cartridge assembly includes a tray detachably connected to a filter cartridge. The tray is positioned beneath the outlet end of the cartridge to remove water treatment particles from the treated water.

Abstract: An efficiency indicator for a separation system, such as a water filter, wherein a first volume of fluid is exposed, under a first pressure, to a separation medium and a second volume of fluid is recovered therefrom, under a second, lesser pressure. The indicator comprises a housing including an aperture and a biased piston rod in a tube driven between a first position and a second spaced-apart position by the differential between said first and second pressures when said second pressure represents an undesired loss of medium separating efficiency. The piston rod has a first reflective colored coating at one location on said rod and a second reflective colored coating at a second location. A sphere of optical transparent material is mounted so as to project through the aperture of the housing.

Abstract: An apparatus for detecting the flow direction of a fluid from an apparatus or between two apparatuses such as a biohoods, fume cabinets, or filters. The device includes a conduit horizontal plane and adapted to receive the fluid. A detecting element is disposed within the conduit and is movable in the direction of fluid flow, the detecting element being in direct contact with the fluid. A sensing element may be coupled to the conduit for determining when the detecting element reaches a predetermined position within the conduit. The circuitry coupled to the sensing element enables selection of a desired flow direction and actuates an alarm when the detected flow direction is other than the one selected.

Abstract: An apparatus for detecting the flow direction of a fluid from an apparatus or between two apparatuses such as a biohoods, fume cabinets, or filters. The device includes a conduit horizontal plane and adapted to receive the fluid. A detecting element is disposed within the conduit and is movable in the direction of fluid flow, the detecting element being in direct contact with the fluid. A sensing element may be coupled to the conduit for determining when the detecting element reaches a predetermined position within the conduit. The circuitry coupled to the sensing element enables selection of a desired flow direction and actuates an alarm when the detected flow direction is other than the one selected.

Abstract: A fluid flow indicator is presented particularly for use within an existing gasoline pumping apparatus. The fluid flow indicator includes an outer cage member, a first hollow transparent cylindrical member contained within the outer cage member, and a second hollow transparent cylindrical member concentrically retained within the first hollow transparent cylindrical member. The fluid flow indicator may also include a filter member and fluid movement detection means contained within the second hollow transparent cylindrical member. The fluid flow indicator is especially designed to be retrofitted within any existing fluid flow line.

Abstract: A fuel dispensing nozzle is provided with a view glass/fuel flow indicator that are disposed between the main fuel valve and a downstream check valve. The view glass/flow indicator means comprise a pair of horizontally aligned view glasses. A plurality of embodiments illustrate the use of different sub-assemblies in providing the view glass/flow indicator functions, as well as different provisions for obtaining a seal that prevents leakage of fuel at the view glass units.

Abstract: An apparatus for use with a water treatment unit and in particular, those having a treatment cartridge, that indicates the end of life of the unit. The apparatus comprises a housing with at least one opening for the passage of liquid to a chamber, formed by the interior of the housing and the water treatment unit. The chamber includes a support member mounted to the housing. A float is rotationally mounted on the support member. The support member limits float movement to a predetermined distance upon each rotation of the float, resulting from each cycle (use) of the water treatment unit. Once the float has made a specific number of rotations and has travelled the complete distance of the support member (as water fills and drains from the chamber), the float rests in a position where it is visible through an opening in the housing, indicative of the end of life of the water treatment unit.

Abstract: A fluid supply system including a casing having at least one duct extending through it for the passage of fluid and a recess in the casing around the duct or ducts, a cover covering the recess and held against a bearing surface on the casing surrounding the recess, the cover carrying a continuation of the or each duct, and a vent in either the casing or the cover communicating the recess with the environment outside the casing, is provided with a leak tell-tale device for indicating passage of fluid along a path, such as the vent, which, in the event of a leakage of fluid from a duct into the recess, would be followed by the leaked fluid.

Abstract: An apparatus for detecting the flow direction of a fluid between two enclosed spaces, such as hospital rooms, includes a conduit extending along a horizontal plane and adapted to receive the fluid. A detecting element is disposed within the conduit and movable in the direction of fluid flow, the detecting element being in direct contact with the fluid. A sensing element may be coupled to the conduit for determining when the detecting element reaches a predetermined position within the conduit. The circuitry coupled to the sensing element enables selection of a desired flow direction and actuates an alarm when the detected flow direction is other than the one selected.

Abstract: In an apparatus for testing pneumatic flow resistance of a test component, such as an air filter useful in a system for admixing parenteral solutions, a pneumatic bridge has two branches connected, via a filter, a flow restrictor, and a flowmeter, to a source of gas under regulated pressure. Each branch comprises two arms with a centerpoint. The bridge has a pressure transducer connected between the centerpoints and arranged to detect pressure imbalances in the bridge. Each arm comprises a flow restrictor, namely a needle valve, which is calibrated via a vernier head. The valves are adjustable to balance the bridge. In one arm, in which the needle valve can be fully opened, the test component is connectible to constitute a flow restrictor. The transducer produces an output displayed via a digital voltmeter, which may be calibrated.

Abstract: A sight flow apparatus includes a body designed to be connected in-line to fluid pipes within a manufacturing plant or other facility. One or more window assemblies are removably mounted on the sides or ends of the body to allow visual inspection of fluid flow through the body cavity. A fluid indicator device i.e., a flapper assembly or a rotor assembly, is mounted within the body cavity and supported by an axle extending between the windows, between the body itself, or between a pair of alignment washers located within the body. The rotor assembly includes a plurality of planar blades which are interconnected to form generally radially extending vanes. An enlarged indicator cap is coupled to each end of the rotor assembly to improve visual examination of fluid flow effects, to lock the interconnected blades together and to prevent the blades from contacting the windows, alignment washer or body.

Abstract: An apparatus for detecting the flow direction of a fluid between two enclosed spaces, such as hospital rooms, includes a conduit extending along a horizontal plane and adapted to receive the fluid. A detecting element is disposed within the conduit and movable in the direction of fluid flow, the detecting element being in direct contact with the fluid. A sensing element is coupled to the conduit for determining when the detecting element reaches a predetermined position within the conduit. Circuitry coupled to the sensing element, enables selection of a desired flow direction and actuates an alarm when the detected flow direction is other than the one selected.

Abstract: A user friendly vapor recovery nozzle with special signaling devices to signal and assure the customer of proper delivery of fuel and return flow of hydrocarbon vapors. In the preferred embodiment, the signaling devices include both a fuel flow indicator and a vapor flow indicator. The flow indicators can comprise one or more fuel and vapor driven balls, paddle wheels, propellers, spinners, blades, or vanes. In the preferred form, the vapor recovery nozzle has an inner fuel spout to discharge gasoline into a customer's tank and has an outer spout which cooperates with the inner spout to provide a vapor return passageway to return vapors emitted during fueling to a vapor return hose. The nozzle has a liquid sensing tube in the vapor return passageway to sense when the customer's tank is filled. An automatic shutoff valve cooperates with the liquid sensing tube to shutoff the supply of gasoline when the customer's tank is filled.

Abstract: A vapor recovery process signals to customers the presence of flow of gasoline or other liquid fuel and the return flow of vapors. In the preferred process, a customer's tank is fueled with a vapor recovery nozzle. Vapors emitted during fueling are collected by the nozzle and passed to a vapor return hose and then into a storage tank. A vapor flow indicator on the nozzle signals flow of vapors passing through the nozzle. A separate fuel flow indicator in the nozzle signals fueling, i.e., passing a fuel through the nozzle into the customer's tank.

Abstract: A system is provided for determining the presence, or absence of a component on the end of a vacuum pickup device. A monitor having a transparent body portion and plural air flow passageways is provided. An indicator is provided for each vacuum pickup device and contained within the air flow passageway intermediate a vacuum source and the vacuum pickup device. The position of the indicators within the flow passage is dependent upon the presence, or absence of a component on the end of the vacuum pickup device. With a component present on the pickup device, air flow through the passageway, due to the application of the vacuum source, is minimal and the indicator will be biased in a first direction. However, when a component is absent the pickup device, substantial air flow occurs through the passageway, thereby biasing the indicator in a second direction.

Abstract: A simple and compact fluid pressure indicator comprising a housing having a passage communicating with the pressure to be monitored leading to an interior chamber, a flexible diaphragm sealing and dividing the chamber into two parts, a colored indicator area on one side of the diaphragm, a light transmitting viewing window axially aligned with and parallel to the indicator area, and a sealed flexible envelope of light-absorbing fluid interposed between the indicator area and viewing window. A change in the monitored pressure causes the diaphragm to flex and the indicator area to be displaced, altering the thickness of the absorbing fluid envelope, and therefore the amount of light reflected from the indicator area. Thus a very small change in pressure will result in a dramatic color change displayed in the viewing window, providing a sensitive pressure indication.

Abstract: A wind gauge includes silica particles dispensed from their container as a floating cloud which is carried along by ambient wind and thus illustrates wind speed and direction. The particulate media may also include a mixture of silica particles and thermoplastic color-pigmented particles, so that the floating cloud is colored and thus more easily visible. The particles may also embody a scent and be used to form a scent trail as they are carried along by the wind and as they gradually settle out of the air.

Abstract: A backflow valve for use in a post-mix carbonator system for preventing the backflow of carbonated fluid, thereby preventing the contamination of the fresh water supply, and indicating when such a backflow condition has occurred. In a first embodiment the valve comprises a check seat body which houses an elastomeric valve member, and a sight glass body for viewing the position of the elastomeric valve member. The elastomeric valve member allows normal the flow of fluid from the supply to the outlet and prevents the reverse flow of fluid when the pressure at the outlet exceeds the pressure at the supply. As the pressure downstream increases, the elastomeric valve member is forced in the upstream direction over a plurality of steps in the check seat body. The position of the elastomeric valve member may be observed through a sight glass body which has a line marking the normal position of the elastomeric valve member.

Abstract: A gas testing apparatus of the type that directs a stream of gas to be tested through a tube containing reagent chemicals. The apparatus has a connector fitting to enable it to be connected to a closed system containing the gas to be tested, a base member having an orifice that reduces the pressure of the gas delivered to the testing tube to near atmospheric, a sliding cover that encloses the testing tube when it is positioned in the holder, and a rising stem indicator that indicates that gas flow has commenced through the tube. The apparatus also has tube seat seals for insuring that all gas entering the apparatus must flow through and not bypass the testing tube.

Abstract: A fractional flow indicator system by which flow in a fluid dispensing conduit is visually indicated using an improved fractional flow diverting element which utilizes a venturi effect rather than a check valve to create a fractional flow pressure differential to induce a fractional fluid flow through a flow indicator. The flow diverting element of the present invention has no moving parts, is easy and relatively inexpensive to manufacture, and does not restrict or reduce the pressure of the main fluid stream flowing therethrough. In accordance with the preferred embodiment, the flow diverting element is constructed from standard elbow components and a short length of copper tubing. The flow indicator system further includes an improved flow indicator having a compact construction with few working parts, which is easy to manufacture, less expensive to produce, and which provides a longer service life than conventional indicators.

Abstract: A fuel dispensing nozzle incorporating sight glass in the vicinity of its poppet valve, which a sight glass is sealingly engaged within the body cap, comprising a lens of either the magnifying or nonmagnifying type, to provide a ready viewing of any activation device within the poppet cavity, either in the form of spinner, or spheres, that are rotated or agitated, as when fuel under pressure is being delivered through the nozzle and to the fuel tank of a vehicle.

Abstract: A fluid flow detection device includes a fluid conduit, at least one magnet translatable by action of the flow of fluid (gas or liquid) in said conduit and a switch which is caused to change state between "on" and "off" relative to the position of the magnet in the conduit. The switch includes several embodiments as does the support for the at least one magnet. In one embodiment the conduit must be positioned in a vertical position in other embodiments the conduit can take any attitude position. A shut off valve can be employed in combination with the flow detection device.

Abstract: A flow sensor for regulating the air flow rate to a cooling system can be formed as a housing for channeling the flow through a retangular cavity and a one piece vane of bent metal strip which deflects and closes an electrical contact at a predetermined air flow rate and opens when the air flow rate falls below a preset threshold level.

Abstract: A method of flow visualization comprises the steps of coating the surface of a component in a pigmented oil-based paint of non-gelling characteristics, applying dry dye particles, which are soluble in the oil based paint to the surface of the coating and passing a fluid flow over the component.The fluid flow causes the dye particles to translate across the coating so that regions of the particles that are in contact with the coating dissolve to leave trails on the surface of the coating which are indicative of the relative strengths of the fluid flows acting on the surfaces of the component.

Abstract: An inexpensive fluid flow indicator capable of use in low flow conditions in a variety of environments, including but not limited to laboratory, industry, and medical applications. Flows are visually indicated by the rotation of balls loosely retained in a longitudinal passageway of the indicator's transparent housing by a flow guide and an outlet port. The flow guide imparts a circumferential or transverse direction to the axial flow of the fluid which causes the balls to revolve about the center line of the indicator.

Abstract: Apparatus for sensing smoke in a duct includes a housing with inlet and outlet ports and a flow chamber which directs gas flow on a path between the ports and to and from a smoke detector. A vaned rotor on the path is visible through a window in the housing gives a visual indication of the existence or nonexistence and direction of gas flow and thus whether or not normally flowing duct gas is being sensed.

Abstract: A rotary sight flow indicator which provides a visual indication of fluid flow and of the flow direction by the rotation of a shrouded cross-flow rotor. The sight flow indicator consists of a housing with a cavity containing the rotor and its shroud, and at least one view window by means of which the fluid inside the housing and the motion of the rotor can be observed. The rotor comprises a number of radial blades attached to a rotatable shaft placed substantially normal to the flow direction. A stationary shroud is positioned around a section of the circumference of the blades which shields the rotor blades from flow impingement during a portion of rotation. The asymmetric flow impingement on the rotor blades so created causes an unbalanced torque and consequently causes the rotor to turn.

Abstract: IA purge block is disclosed in which inlet, process, purge and vent ports are series connected in a ring or bridge. The channel or passageway connecting the inlet and purge ports comprises a flow sensor. The impedance to gas flow of each channel is different from the others. The impedances are chosen such that improper operating conditions cause an imbalance in the flow which is detected by the flow sensor. During normal operation of the system in which the purge block is used, the flow sensor acts as an excess flow detector by comparing the flow through itself with the flow through a parallel, but more restrictive, path within the purge block.

Abstract: A flow indicator and a method for monitoring the operation of a chemical feed pump are provided. This indicator includes a housing defining a flow chamber and having an inlet through one end and an outlet through the other end. The inlet and the outlet of the housing are in communication with the fluid conduit of the pump, and the flow chamber is a vertical component of the flow path of the fluid flowing through the conduit. The housing contains two freely movable balls in the flow chamber, one ball having a specific gravity greater than that of the fluid and the other having a lower specific gravity. It is at least partially transparent to enable the operator of the indicator to observe the movement of the balls. The method for monitoring the pump involves placing the two balls in the flow chamber, connecting the indicator to the fluid conduit, operating the pump, and observing the action of the balls.