Abstract: An aircraft engine includes an air inlet duct and at least one strut having a leading edge and a trailing edge. The at least one strut extends across at least part of the air inlet duct and has a strut passage. The trailing edge has one or more edge contours, each defining a contour edge wall recessed from a baseline surface of the trailing edge. The one or more edge contours have a recessed tap in fluid communication with the strut passage.

Abstract: A wellbore system includes a wellbore tubular with local inner diameter variation. The system includes a wellbore tubular that is positionable in a wellbore for producing hydrocarbon fluid. The wellbore tubular includes at least one portion of an inner wall with a greater inner diameter than other portions of the inner wall of the wellbore tubular. The system includes a fiber optic cable of a fiber optic sensing system that is positionable in the wellbore for measuring flow disturbance of production fluid at the at least one portion of the inner wall to monitor hydrocarbon production flow.

Abstract: An aircraft engine, has: a pressure probe having: a static member having a front face and a back face, an inlet and an outlet fluidly connected to the inlet, the front face defining a curved surface; a movable member movably engaged to the static member and movable relative to the static member about a center of rotation, the movable member having a central axis, the movable member having an engagement section matingly engaged to the front face to slide against the curved surface, the engagement section having an opening, and an orientation section protruding from the engagement section and located rearward of the center of rotation, the orientation section defining an external surface exposed to the flow, wherein the movable member is movable relative to the static member as a result of a force imparted by the flow on the external surface.

Abstract: A method can include vapor depositing a corrosion resistant coating to internal and external surfaces of a metallic air data probe. For example, vapor depositing can include using atomic layer deposition (ALD). The method can include placing the metallic air data probe in a vacuum chamber and evacuating the vacuum chamber before using vapor deposition. The corrosion resistant coating can be or include a ceramic coating. In certain embodiments, vapor depositing can include applying a first precursor, then applying a second precursor to the first precursor to form the ceramic coating.

Abstract: An air date probe includes a strut assembly extending from a base, and a tube assembly coupled to the strut assembly. One or both of the strut assembly and the tube assembly comprises a self-regulating thin film heating arrangement. The self-regulating thin film heating arrangement includes at least one circuit including a positive temperature coefficient (PTC) heating element connected in series with a negative temperature coefficient (NTC) heating element.

Abstract: There is provided a device and a method of operating the device for determining whether the device is immersed in a fluid. An acceleration signal for the device is acquired (302) and a pressure within the device is detected (304). It is determined whether the device is immersed in a fluid based on a comparison of the acquired acceleration signal with the detected pressure (306).

Abstract: A measuring device for measuring at least one parameter of an aerodynamic flow of a turbine engine. The device operates to collect parameters of the flow. A body extends along a radial axis (L). A connecting part is fastened to a first end of the body and designed to secure the measuring device to a radially outer wall of the turbine engine. A stud is inserted and mounted on a second end of the body radially opposite the first end. The stud includes at least a portion of a rubberlike material designed to come into contract with a radially inner wall of the turbine engine.

Abstract: A product for pressure measurements is provided. The product being integral to a component comprising a conduit encasing a flow path of a medium. The product includes static pressure holes, located on the conduit, that access the flow path and the medium. The product includes a static port, which provides a volume that includes an average static pressure across the static pressure holes. The product includes channels, each which directly corresponds to and fluidly couples each static pressure hole to the static port.

Abstract: A pitot-static array system for a tail-sitting aircraft has a disk with a plurality of edge ports arrayed about an edge of the disk. Each of a plurality of pressure transducers is configured to measure air pressure at one of the edge ports. The edge ports are arrayed about an axis parallel to a pitch axis of the aircraft.

Abstract: An air data probe includes a probe head, a port within the probe head in fluid communication with external airflow, and a pneumatic pressure sensor mounted within the port.

Abstract: A device that measures turbomachine aerodynamic flow parameters is presented. The device includes the information collection elements relating to the flow parameters, and a body that includes the information collection elements. The body features a portion that is elongated in the longitudinal direction and configured to form the leading edge of a turbomachine vane, and a first side portion that laterally extends portion in an axial direction, wherein the information collection elements protrude from the leading edge of the portion and the portion includes internal channels that route the information and individually communicate with at least one information collection elements, wherein the first side portion features a first surface configured to fit, at least partially, onto a second surface of an intrados or extrados wall of a turbomachine vane.

Abstract: An air speed probe with a cylindrical probe body having a length, and a frusto-conical tip at an end of the cylindrical probe body. A center bore with a first diameter and first depth is formed in a center of the tip and coaxially disposed along a portion of the length of the cylindrical probe body. Radial bores with second diameters and second depths are formed in a sidewall of the tip, where the first diameter is wider than the second diameter, and the first depth is shallower than the second depth.

Abstract: An insertion-type flowmeter adapted for removable insertion into a fluid conduit includes an elongate body having a flow opening and a vortex-generating element disposed within the flow opening at distance from the opening entry that is correlated to the size of the flow opening to define a flow conditioning space in the flow opening between the opening entry and the vortex-generating element.

Abstract: A water heater venting system, the water heater venting system comprising a main exhaust vent; and a first water heater in communication with a second water heater. The first water heater including an inlet, a blower assembly including a motor, an exhaust vent coupled to the main exhaust vent, a fluid flowpath created by fluid communication between the inlet, the blower assembly, and the exhaust vent, a sensor positioned along the fluid flowpath, and a controller electrically coupled to the sensor and the motor of the blower assembly, the controller controlling the speed of the motor based on at least one of an input from the sensor and an input from the second water heater.

Abstract: A flow sensor sub-assembly includes a flow tube having a lumen, an outside diameter, a first end, and a second end. An inlet fitting includes a conical orifice sized for insertion in either end of the flow tube, such that an internal passage of the inlet fitting is coaxial and concentric with the lumen and the end of the flow tube abuts a shoulder. An outlet fitting includes a conical orifice sized for insertion in either end of the flow tube, such that an internal passage of the inlet fitting is coaxial and concentric with the lumen and the end of the flow tube abuts a shoulder. A first piezo element integrated with the inlet fitting is arranged at an upstream position of the flow tube assembly and a second piezo element integrated with the outlet fitting is arranged at a downstream position of the flow tube assembly.

Abstract: A system for sensing medicament delivery and transmitting an operation modification signal having at least two separable components is disclosed. The system includes a flow sensor having an inlet to couple to a fluid source, an outlet for delivering fluid from the fluid source to a patient, at least one sensor to characterize at least one attribute of the fluid, and at least one pin in in electrical communication with the sensor. The system includes a second component having a base having a contact, a controller in electrical communication with the contact that generates an operation modification signal in response to an attribute matching a condition specified by a rule, a transmitter for transmitting the operation modification signal to a device, the operation modification signal, when received by the device, causing the device to modify at least one operating parameter, and a cross-component electrical circuit.

Abstract: A system and method of measuring duct leakage in an HVAC system including an indoor unit assembly operably coupled to a processing device, wherein at least one supply air conduit, and at least one return air conduit are coupled to the indoor unit assembly by operating a blower system at a nominal airflow rate, restricting airflow in each of the at least one supply air conduits, and each of the at least one return air conduits; operating the blower system, within the indoor unit assembly, at a first airflow rate; and operating the processing device to calculate a duct leakage airflow and duct leakage measurement.

Abstract: An insertion-type flowmeter adapted for removable insertion into a fluid conduit includes an elongate body having a flow opening and a vortex-generating element disposed within the flow opening at distance from the opening entry that is correlated to the size of the flow opening to define a flow conditioning space in the flow opening between the opening entry and the vortex-generating element.

Abstract: A system for sensing medicament delivery and transmitting an operation modification signal having at least two separable components is disclosed. The system includes a flow sensor having an inlet to couple to a fluid source, an outlet for delivering fluid from the fluid source to a patient, at least one sensor to characterize at least one attribute of the fluid, and at least one pin in in electrical communication with the sensor. The system includes a second component having a base having a contact, a controller in electrical communication with the contact that generates an operation modification signal in response to an attribute matching a condition specified by a rule, a transmitter for transmitting the operation modification signal to a device, the operation modification signal, when received by the device, causing the device to modify at least one operating parameter, and a cross-component electrical circuit.

Abstract: A total air temperature sensor includes a probe head, a strut, and a turbulence inducing surface. The probe head has an airflow inlet and an airflow outlet. The strut defines a leading edge and an opposed trailing edge extending along a longitudinal axis, and connects between the probe head and an opposed probe mount. The turbulence inducing surface is defined in the strut aft the leading edge. The turbulence inducing surface is configured to trip a fluid boundary layer passing over the strut to transition from laminar to turbulent for moving flow separation toward the trailing edge to reduce acoustic noise emission from the total air temperature sensor.

Abstract: A flow sensor sub-assembly includes a flow tube having a lumen, an outside diameter, a first end, and a second end. An inlet fitting includes a conical orifice sized for insertion in either end of the flow tube, such that an internal passage of the inlet fitting is coaxial and concentric with the lumen and the end of the flow tube abuts a shoulder. An outlet fitting includes a conical orifice sized for insertion in either end of the flow tube, such that an internal passage of the inlet fitting is coaxial and concentric with the lumen and the end of the flow tube abuts a shoulder. A first piezo element integrated with the inlet fitting is arranged at an upstream position of the flow tube assembly and a second piezo element integrated with the outlet fitting is arranged at a downstream position of the flow tube assembly.

Abstract: The invention relates to an instrumented airfoil for mounting in a flow passage through a turbine, compressor, or module of a turbine engine. An instrumentation member is attached to an airfoil and includes information-obtaining means received in a cutout formed in the airfoil and projecting relative to the leading edge or the trailing edge. According to the invention, the instrumentation member also comprises a holder portion that is united with the information-obtaining means and that is attached to the cutout in such a manner that its surface is in alignment respectively with the suction side wall, the pressure side wall, and the leading edge or the trailing edge of the airfoil, the transitions between these respective surfaces not presenting any setbacks.

Abstract: A modular removable flow metering assembly for a unidirectional fluid channel having three variations. Each embodiment can use a compact fluid conduit for connecting an upstream fluid flow to a downstream fluid flow. An embodiment uses a unitary dual measurement container having an upstream port opening opposite to a downstream port. The upstream port communicates with an upstream fluid channel with an upstream pressure. The downstream port communicates with a downstream fluid channel having a downstream pressure. A cone shaped differential pressure producer with a flared discharge end is in fluid communication with the downstream fluid channel. A manifold can fluidly connect the upstream and downstream fluid channels, and a customer connection device can receive the upstream pressure and downstream pressure.

Abstract: A pitot tube includes a substantially cylindrical body portion having an interior defining a flow passage, and a tip portion extending along a pitot tube axis from the body portion. The tip portion includes an inlet opening, a radially tapered outer surface extending from the body portion toward the inlet opening, one or more bulkheads disposed at the interior to limit travel of particles ingested into the interior, at least one drain opening disposed directly adjacent to one of the one or more bulkheads, and one or more electrical coils comprising one or more coil wraps disposed at an interior of the pitot tube. The one or more coil wraps establish a variable watt density along the interior of the pitot tube. The one or more coil wraps also establish a variable watt density downstream of one or more of the one or more bulkheads.

Abstract: A dust measurement system measuring the build up of dust on a filter includes a monitoring device, a pitot tube, and an environment control unit. The pitot tube head aligned with the filter. The environment control unit receives the measured speed of air flow and compares the measured speed with a preset value. When the measuring speed is greater than the preset value, the environment control unit outputs the first control signal to the monitoring device, to control the monitoring device to display that the filter does not need to be replaced. When the measuring speed is less than or equal to the preset value, the environment control unit outputs the second control signal to the monitoring device, to control the monitoring device to display that the filter needs to be replaced.

Abstract: An airway adaptor that measures the concentration of at least one of a specific component and the flow rate of a supply gas and a return gas. The airway adapter may include a tube having a flow path in which the supply gas and the return gas passes. The tube may include a first end having a first aperture for guiding the supply gas into the flow path, and second end having a second aperture for guiding the return gas. Further, the airway adapter may include a measurement device operable to measure at least one of the supply gas and the return gas in the air flow path and a partial shielding disposed at the first aperture and structured to shield a portion of the air flow path. The supply gas may be a respiratory gas and the return gas may be inhaled or exhaled breath of a person.

Abstract: A method and apparatus for measuring static pressure. A tube is positioned within a hole in a structure. The hole has a hole diameter that is larger than a tube diameter of the tube such that a gap is formed between the tube and the hole. A first portion of deflected fluid that is deflected from a flow of fluid passing over the hole enters the gap and a second portion of the deflected fluid enters the tube. The static pressure of the fluid is measured at a location of the hole with the tube positioned within the hole.

Abstract: Flow sensor includes a housing having a chamber and a tube extending therefrom. Static and stagnation pressure ports are located along the tube and open in different directions about a periphery. A first conduit fluidly couples the static pressure port to the chamber, and a first pressure sensor senses the fluid pressure in the chamber. A differential pressure sensor has a first port and a second port in the chamber. The first port senses the fluid pressure in the chamber, and a second conduit fluidly couples the stagnation pressure port with the second port. The second port is more exposed to fluid flow through the pipe relative to the first port. Fluid flow rate through the pipe is determinable based on static fluid pressure sensed by the first pressure sensor, differential pressure measured by the differential pressure sensor, density of fluid in the pipe, and diameter of the pipe.

Abstract: A fluid regulating device includes a regulator valve having an inlet, an outlet, and a valve port disposed between the inlet and the outlet. An actuator is coupled to the regulator valve and includes a valve disc that displaces between a closed position and an open position. The device also includes an overpressure protection device adapted to stop flow from the inlet to the outlet when pressure in a control cavity reaches a predetermined level. The overpressure protection device includes a sensing tube having a first end in fluid communication with the control cavity and a second end in fluid communication with the outlet. The sensing tube has a first portion extending parallel to the flow axis. One or more apertures are disposed in the sensing tube adjacent to the second end, and each of the apertures has a centerline that is perpendicular to the flow axis.

Abstract: A dynamic fiber temperature sensing package is provided herein. The sensing package includes a support structure, a holder coupled to the support structure, a sheath coupled to the support structure via the holder, and a fiber optic temperature sensor positioned within the sheath. The holder includes a material having a first thermal conductivity and the sheath includes a material having a second thermal conductivity, wherein the second thermal conductivity is greater than the first thermal conductivity.

Abstract: An improved HVAC air handler and control system adapted for measuring and monitoring operating characteristics, the leakage of supply and return ducts to which it is connected, the infiltration leakage of the building it serves, the blockage of air return paths and the watts drawn and air flow generated by its blower. Leakages are measured by blocking outlets of all supply ducts or all return ducts, opening one side of the air handler to outdoor air, running the air handler blower, and measuring the air flow. Airflow may be measured by opening or closing orifices mounted in plenums attached to the air hander or built into the air handler cabinet, or by varying the speed of the blower motor, in connection with an integrated manometer. Thermostat firmware controls all functions.

Abstract: A pitot tube system having a pitot tube containing a porous hydrophobic fabric that blocks water and contaminants from reaching a pressure sensor. The distance in the pitot tube between the fabric and a front orifice of the tube is less than 2.4 times the height of the orifice, and preferably less than or equal to 0.38 times the height. The section of the tube through which the fabric extends defines an opening characterized by a minimum dimension greater than 0.15 inches, and preferably being at least 0.21 inches. The tube is a removable structure that attaches to a mount that forms a passage for communicating the pressure in the tube. That passage contains a second porous hydrophobic fabric that also blocks water and contaminants from reaching a pressure sensor.

Abstract: A pitot tube assembly is provided for a radiant tube heater having a blower for providing combustion air to a burner. The assembly includes a mounting plate for attaching the assembly to a wall of a housing of the blower. First and second, substantially L-shaped pitot tubes extend through the mounting plate and are connected thereto and have respective inner leg sections which are arranged within an outlet section of the blower during use of the radiant tube heater. These leg sections extend in opposite directions to their respective pressure sensing ends. The first pitot tube measures impact pressure created by the blower and the second pitot tube measures static pressure. These tubes are connectible to a differential pressure switch arrangement for controlling operation of the burner. As part of a burner assembly, there is a mixing cup unit mountable within the burner tube of the heater and capable of mixing primary air and combustible gas. A gas valve unit regulates flow of the gas to the cup assembly.

Abstract: A calibration method for a flow measuring device used with a vehicle exhaust analysis system includes the flow measuring device being connected with the vehicle exhaust system wherein exhaust gases are directed through the flow measuring device. A portable flow calibration device is connected in a manner that exhaust gases of the vehicle exhaust system are directed through the portable flow calibration device. The vehicle is operated so that exhaust gas flows through the flow measuring device and the flow calibration device. The flow measuring device is calibrated with the portable flow calibration device. The flow measuring device includes a Pitot tube assembly in a flow tube wherein gas flowing through the flow tube passes the Pitot tube assembly. The Pitot tube assembly includes a sensing tube and at least one pressure sensing port connected with the sensing tube. The sensing tube includes a plurality of sensing openings that are positioned at different portions of gas flowing through the flow tube.

Abstract: Average pitot-tube type flow meter according to the present invention has a total pressure tube and a static pressure tube. The total pressure tube and the static pressure tube are spaced from each other. Across the total pressure tube and the static pressure tube, a rectifying device and a connection case are installed as they are integrated into one body. The rectifying device is positioned in advance of total pressure holes and the total pressure hole and a static pressure hole are positioned inside the connection case.

Abstract: A differential pressure flow measurement system includes a pressure sensor coupled to measurement circuitry. An elongate probe is configured to be inserted into a conduit which carries a flow of process fluid. The pressure sensor senses a pressure difference in the fluid flow generated as the fluid flows past the probe. A vortex shedding stabilizer is positioned proximate the elongate probe and in the flow of process fluid. The vortex shedding stabilizer is configured to stabilize vortex shedding in the flow of fluid proximate the elongate probe.

Abstract: According to the invention a device for precise metering of a fluid volumetric flow of low flow rates down to zero volumetric flow of a liquid component in a mixer feed line for mixing plastics is provided, the device having a fluid supply tank that is in fluid line communication with the mixer feed line via a pump and through a volumetric flow meter, is characterized in that a fluid return line, which leads back into the tank through a second volumetric flow meter and which branches off from one of the fluid lines between the tank and the mixer feed line downstream of the first volumetric flow meter through a distributor apparatus that has one input and two outputs, namely one into the return line and one into the mixer feed line, and that distributes an input volumetric flow into the two outputs, and specifically in an adjustable fluid rate ratio.

Abstract: A pneumatically actuated valve includes a valve body, a pneumatic actuator, and a pitot tube. The valve body includes a valve disc positioned in a valve housing that defines a flow passage with a flow passage diameter. The pneumatic actuator rotates the valve disc in the valve housing. The pitot tube is connected to the pneumatic actuator and has a tip extending into the flow passage. The tip is spaced apart from the valve housing by at least 1/20 of the flow passage diameter. The tip is substantially free of downstream obstructions for a distance equal to at least ½ of the flow passage diameter when the valve is in an open position.

Abstract: A dust measurement system measuring the build up of dust on a filter includes a monitoring device, a pitot tube, and an environment control unit. The pitot tube head aligned with the filter. The environment control unit receives the measured speed of air flow and compares the measured speed with a preset value. When the measuring speed is greater than the preset value, the environment control unit outputs the first control signal to the monitoring device, to control the monitoring device to display that the filter does not need to be replaced. When the measuring speed is less than or equal to the preset value, the environment control unit outputs the second control signal to the monitoring device, to control the monitoring device to display that the filter needs to be replaced.

Abstract: A Kiel-style pressure probe includes pressure tubing having a remote sending end, the pressure tubing extending through an open-ended shroud, wherein the shroud has a diameter of at least about 0.375 to 0.50 inch and wherein a forward end of the shroud is formed with at least two drainage apertures in proximity to the remote sensing tip of the pressure tubing.

Abstract: A pitot tube system having a pitot tube containing a porous hydrophobic fabric that blocks water and contaminants from reaching a pressure sensor. The distance in the pitot tube between the fabric and a front orifice of the tube is less than 2.4 times the height of the orifice, and preferably less than or equal to 0.38 times the height. The section of the tube through which the fabric extends defines an opening characterized by a minimum dimension greater than 0.15 inches, and preferably being at least 0.21 inches. The tube is a removable structure that attaches to a mount that forms a passage for communicating the pressure in the tube. That passage contains a second porous hydrophobic fabric that also blocks water and contaminants from reaching a pressure sensor.

Abstract: A process variable transmitter is configured as a flowmeter for measuring flow of a process fluid through a conduit. The transmitter includes a pitot tube extending into the conduit which creates a differential pressure in the process fluid due to flow of the process fluid. An upstream process variable sensor is mounted on the pitot tube and coupled to the flow of process fluid to sense an upstream process variable of the process fluid. A downstream process variable sensor is mounted on the pitot tube downstream of the upstream process variable sensor and coupled to the flow of process fluid to sense a downstream process variable of the process fluid. Measurement circuitry determines the flow of the process fluid based upon the upstream process variable and the downstream process variable.

Abstract: A method for measuring the flow rate of a fluid using a differential pressure sensor is presented. In this method, two pitot tubes are positioned within in flowing fluid, creating a pressure differential that is converted to a voltage by a differential pressure sensor. The voltage is transmitted to a programmable microcontroller for computation of flow rate based on a calibration procedure that was been used to determine the relationship between voltage and flow rate. The microcontroller may also be used to correct for temperature variations, store fluid flow rates, calculate the total volume of fluid that has passed, transmit data, display data, modify the fluid flow, or automatically run a calibration routine.

Abstract: A device used in making differential measurements of a flow includes a flow obstruction and a support arm. The flow obstruction's forward portion is a nose cone. The flow obstruction's aft portion is coupled to the nose cone. The support arm's first end is coupled to an exterior wall of a conduit, and its second end is coupled to the forward portion of the flow obstruction. The support arm positions the flow obstruction in the conduit such that a flow region is defined around its nose cone, and such that the support arm's first and second end are separated from one another with respect to a length dimension of the conduit. Measurement ports are provided in the support arm and flow obstruction. Manifolds extending through the flow obstruction and support arm couple the ports to points at the exterior wall of the conduit.

Abstract: To achieve accurate and rapid acquisition or distribution of fluid—at multipoints—with good spatial resolution and minimal bulk, a twisted arrangement of ducts is provided in the acquisition/distribution zone making it possible to perform several acquisitions/distributions over several heights with one and the same device. The device is a pressure probe in which a probe body exhibits a first part or section for acquiring pressure forming a cylinder less than 6 mm in diameter. The probe exhibits internal ducts forming parallel helicoidal traces on the section and channels formed in a metal alloy body between the ducts and inlet orifices. The number of internal ducts is advantageously equal to nine, including three orifices being disposed over three different heights of the probe body.

Abstract: Apparatus and methods for measurement of airflow in a duct are described. The apparatus combines a Pitot tube, sensing apparatus, control apparatus, a display, control switches and carry apparatus arranged into a unitary structure.

Abstract: A fluid flow tool's plate-like structure has a ring portion defining a flow hole, a support portion extending radially away from the ring portion and adapted to be coupled to conduit wall, and extensions extending radially away from the ring portion such that a periphery of the plate-like structure is defined by the extensions and trough regions between adjacent extensions. One or more ports formed in the ring portion are in fluid communication with the flow hole. A first manifold in the plate-like structure is in fluid communication with each port communicating with the flow hole. One or more ports are formed in the periphery of the plate-like structure. A second manifold in the plate-like structure is in fluid communication with each port formed in the periphery. The first and second manifolds extend through the plate-like structure to terminate and be accessible at the conduit wall.

Abstract: A fluid flow tool includes an airfoil structure and a support arm. The airfoil structure's high-pressure side and low-pressure side are positioned in a conduit by the support arm coupled to the conduit. The high-pressure and low-pressure sides substantially face opposing walls of the conduit. At least one measurement port is formed in the airfoil structure at each of its high-pressure side and low-pressure side. A first manifold, formed in the airfoil structure and in fluid communication with each measurement port so-formed at the high-pressure side, extends through the airfoil structure and support arm to terminate and be accessible at the exterior wall of the conduit. A second manifold, formed in the airfoil structure and in fluid communication with each measurement port so-formed at the low-pressure side, extends through the airfoil structure and support arm to terminate and be accessible at the exterior wall of the conduit.

Abstract: A pitot tube includes a substantially cylindrical body portion and a tip portion extending along a pitot tube axis from the body portion. The tip portion includes an inlet opening and a radially tapering outer surface extending from the body portion toward the inlet opening. Another pitot tube includes a substantially cylindrical body portion and a tip portion extending along a pitot tube axis from the body portion. The tip portion includes an inlet opening. One or more electrical coils including one or more coil wraps are located at an interior of the pitot tube. One or more bulkeads are located between a forwardmost coil wrap and a drainage feature to limit travel of particles ingested into the interior.

Abstract: Apparatus and method for providing the apparatus, the apparatus including: a duct; and a non-return valve; wherein the duct has a first portion and a second portion; the first portion has a first end and a second end; the first end is open to a fluid (e.g. air); the second end is connected to the second portion such that fluid is permitted to flow between the first portion and the second portion; the non-return valve is positioned at or proximate to the second end; and the non-return valve is arranged such that, upon application of a suction force to the first portion at the first end, fluid flows into the first portion via the non-return valve from outside the duct, and through the first portion from the second end to the first end.