Pressure limiting device

Abstract

This invention relates to a pressure limiting device, particularly a pressure limiting adapter, comprising a housing, a first air opening element, and a second air opening element, wherein the first air opening element is disposed on a first housing portion, and the second air opening element is disposed on a second housing portion different from the first housing portion. The pressure limiting device is proposed to have an air pressure limiting unit for limiting air pressure, particularly by means of the first and second housing portions.

Description

Technical Field

[0001] This invention relates to a pressure limiting device as described in the specification. Background Technology

[0002] Basic pressure limiting devices are known from existing technology. Summary of the Invention

[0003] The objective of this invention is to improve a pressure limiting device, particularly a pressure limiting adapter, using simple structural measures.

[0004] The task is accomplished by a pressure limiting device, particularly a pressure limiting adapter, having a housing, a first air opening element, and a second air opening element, wherein the first air opening element is disposed on a first housing portion, and the second air opening element is disposed on a second housing portion different from the first housing portion.

[0005] It is suggested that the pressure limiting device has an air pressure limiting unit for limiting the air pressure of the pressure limiting device, particularly by means of a first housing portion and a second housing portion constituting the pressure limiting device.

[0006] Pressure limiting devices, particularly pressure limiting adapters, can constitute a technical component for limiting pressure, especially overpressure and / or negative pressure, within a system to a predetermined maximum value to prevent damage caused by overpressure. The device can be designed to operate in systems with airflow, where air pressure can be continuously monitored and / or regulated. The pressure limiting device typically consists of a housing with an inlet and an outlet for airflow, and an internal mechanism that measures / monitors pressure and expels excess air when a defined limit is exceeded. This can be achieved using spring-loaded valves, diaphragms, or other pressure-sensitive elements that open to adapt to air pressure, particularly reducing or increasing it. The pressure limiting device may also be equipped with additional components, such as pressure sensors, regulating valves, and safety devices, to ensure accurate and reliable pressure limiting.

[0007] In this context, the first and / or second air opening elements may relate to components within the pressure limiting device that enable controlled entry and exit of airflow. The first air opening element typically constitutes an inlet through which air enters the pressure limiting device. The first air opening element may be equipped with a filter or check valve to ensure that only purified air reaches the system and to prevent backflow. The second air opening element may constitute an outlet through which air exits after pressure regulation. The second air opening element may be provided with a valve or throttling device to precisely control the airflow and ensure that the pressure within the system is maintained at a desired level. The two air opening elements constitute the functionality of the pressure limiting device in that they regulate the airflow into and out of the system and thereby help maintain a safe and stable operating pressure. The first air opening element may be arranged on the side of the housing opposite to the second air opening element. The first air opening element may be arranged coaxially with the second air opening element.

[0008] The housing of the pressure limiting device can be (especially precisely) composed of two separate housing portions. The housing extends along a longitudinal axis. A first housing portion and / or a second housing portion are rotatably supported relative to the longitudinal axis. The first housing portion can be configured to allow air inflow into the pressure limiting device. The second housing portion can be configured to allow air outflow from the pressure limiting device. The arrangement of air inlet elements on the different housing portions enables efficient and controlled guidance of airflow through the pressure limiting device. This spatial separation of the inlet and outlet elements helps ensure optimized pressure regulation by guiding airflow through different internal mechanisms of the device. This ensures effective monitoring and regulation of air pressure within the device, improving the overall system performance and reliability.

[0009] In this context, an air pressure limiting unit, used to limit the air pressure of a pressure limiting device, can constitute a component or assembly within the pressure limiting device. Its design aims to limit the air pressure to a predetermined maximum value, thereby preventing overpressure. This unit typically includes multiple functional elements, such as a pressure sensor, regulating valve, and control mechanism, which work together to continuously monitor and regulate the air pressure. When a predetermined pressure limit is reached or exceeded, the air pressure limiting unit automatically activates a mechanism, such as a spring-loaded valve or diaphragm, which expels excess air to reduce the pressure. The unit may also be equipped with an electronic controller and alarm system to ensure accurate and reliable pressure limiting and to notify the user of critical pressure ratios. The air pressure limiting unit is the central component of the pressure limiting device, ensuring the safety and efficiency of the entire system by maintaining the air pressure within safe operating limits. Air pressure limiting units can be constructed as pressure sensors, regulating valves, spring-loaded valves or diaphragms, electronic controllers, and alarm systems.

[0010] Practically speaking, the air pressure limiting unit can be configured to limit negative pressure or overpressure. When a critical pressure value is reached, the air pressure limiting unit automatically activates the corresponding mechanism, such as a regulating valve or a spring-loaded valve, which either releases air to reduce overpressure or introduces air to balance negative pressure. Through this comprehensive configuration, the air pressure limiting unit ensures that the air pressure within the device is always maintained within safe operating limits, thereby improving the integrity and reliability of the entire system and preventing damage caused by pressure deviations.

[0011] Practically speaking, the air pressure limiting unit may have a third air opening element for limiting air pressure, wherein the first and / or second air opening elements are larger than the third air opening element, particularly at least 300% larger, preferably more than 400%, more preferably more than 600%, and even more preferably more than 1000%. The first air opening element may be larger than the second air opening element, particularly at least 10% larger, preferably 20%, more preferably 30%, even more preferably 40%, particularly preferably 50%, and / or particularly smaller than at most 120%, preferably 110%, more preferably 100%, even more preferably 90%, and particularly preferably 80%. In detail, this means that, in addition to the main air opening elements that function as inlet and outlet, the air pressure limiting unit also includes an additional third air opening element specifically for finely adjusting the air pressure. The size of this third air opening element is significantly smaller than the first and / or second air opening elements, wherein the size difference is at least 300% and preferably even larger, to ensure precise control of airflow. The significantly larger size of the first and / or second air inlet elements compared to the third air inlet element allows for coarse regulation of the main airflow, while the smaller third air inlet element allows for fine-tuning of the air pressure. This arrangement improves the device's adaptability to different pressure ratios and enhances the accuracy of pressure regulation. By combining air inlet elements with different sizes, the pressure limiting unit can efficiently handle large volume flow rates and perform fine pressure matching, significantly improving the overall performance and versatility of the pressure limiting device.

[0012] Practically, the air pressure limiting unit may have a third and / or fourth air opening element, particularly an adjustable third and / or fourth air opening element, which is composed of two housing portions, particularly the housing portions defining the first and / or second air opening elements. The third and / or fourth air opening elements may be integrated components of the housing portions surrounding the first and / or second air opening elements. The housing of the pressure limiting device may be configured such that it includes not only the main air opening elements (inlet and outlet) but also integrates additional third and / or fourth air opening elements. The third air opening element is directly formed by the structure of the housing portions defining the first and / or second air opening elements. This configuration allows for a compact and efficient arrangement of the air opening elements within the device, thereby minimizing space requirements and improving structural integration. The housing portions surrounding the first and / or second air opening elements may be configured such that they contain the third and / or fourth air opening elements, which can be flexibly adapted to precisely regulate airflow. This adjustability can be achieved through various mechanisms, such as movable or rotatable components within the housing portion, which alter the size of the opening or the position of the airflow. The third and / or fourth air opening elements, formed by the housing portion, enable an additional layer of control over the air pressure within the device by allowing for finer airflow adaptation. These third and / or fourth air opening elements can be used to finely regulate the air pressure within the device by providing additional paths for airflow defined by the housing portion itself. This integration into the housing portion enables precise control of air pressure and improves the overall functionality of the pressure limiting device by ensuring seamless and efficient airflow guidance. By cleverly utilizing the housing portion to form the third air opening element, the complexity of the device is reduced while simultaneously improving its performance and reliability.

[0013] Practically, a fourth air opening element can be adapted to a third air opening element, and / or cover or overlap each other in at least one open state, and / or not cover or overlap each other in at least one closed state. The fourth air opening element can be configured and / or positioned such that it interacts with the third air opening element in a specific manner. This adaptation may involve the two air opening elements being partially or completely above or overlapping each other in the open state, thereby creating a common airflow passage that enables or enhances airflow. Conversely, in the closed state, the two air opening elements are arranged such that they do not cover or overlap each other, thereby interrupting or strongly restricting airflow. This configuration allows for precise control of air pressure by opening or closing airflow as needed. The possibility of positioning the air opening elements in different states provides high flexibility in pressure regulation and enables accurate control of air pressure within the device. This arrangement contributes to the efficiency and functionality of the pressure limiting device by enabling seamless adaptation to different operating conditions and optimizing system performance.

[0014] Practically, an air pressure limiting unit, particularly a third and / or fourth air opening element, can be arranged between the first and second air opening elements. Thus, by means of the specific arrangement of the air opening elements within the pressure limiting device, optimized control of airflow can be achieved. The air pressure limiting unit can be configured such that the third and / or fourth air opening elements are spatially positioned between the first air opening element, which typically functions as an inlet, and the second air opening element, which functions as an outlet. This arrangement enables graded and controlled guidance of airflow through the device. The third and / or fourth air opening elements can here act as additional regulating stages, further refining the air pressure before the air reaches the outlet. By placing these additional air opening elements between the inlet and outlet, finer coordination of air pressure within the device can be achieved, resulting in improved pressure regulation. This configuration contributes to the efficiency and functionality of the pressure limiting device by ensuring uniform distribution of air pressure and providing the possibility of controlling airflow in multiple levels.

[0015] Practically, the locking element can be constructed as a first housing portion, wherein the first housing portion is movably supported and overlapped relative to a second housing portion. This provides a specific structure within the pressure limiting device, wherein the locking element is an integrated component of the housing and enables the movement of the airflow for control. In detail, this means that the locking element is not constructed as a separate component, but rather as the first housing portion itself. This first housing portion is constructed such that it is movably supported relative to the second housing portion, wherein the movement preferably includes rotational movement. This rotatable support allows the first housing portion to rotate relative to the second housing portion, thereby changing the position of the air opening element and thus altering the airflow within the device. The overlapping arrangement of the two housing portions ensures that they are partially or completely overlapped in specific positions, enabling precise control of the airflow. By rotating the first housing portion, the user can open or close the airflow by changing the overlap of the air opening elements. This structure provides a robust and reliable method for regulating air pressure because it minimizes the number of moving parts and increases the structural integration of the device. Integrating the locking element into the housing simplifies the design and improves user-friendliness, as the operator can control the air pressure through simple rotation of the housing portion. This arrangement contributes to the efficiency and functionality of the pressure limiting device by enabling flexible and precise adaptation to different operating conditions.

[0016] Practically, a first air opening element can be configured to connect to a negative pressure generating unit, particularly a suction device, and / or a second air opening element can be configured to connect to an overpressure generating unit, particularly a pump device. This provides specific functionality and connection possibilities for the air opening elements within the pressure limiting device, enabling diverse applications in different pressure systems. The first air opening element can be configured to establish a connection with a negative pressure generating unit, such as a suction device. This connection allows air to be removed from the system, thereby generating the negative pressure required for a specific application. Simultaneously, the second air opening element is configured to connect to an overpressure generating unit, such as a pump device. This connection allows air to be pumped into the system to generate the same overpressure required for different applications. By offering the possibility of connecting the first air opening element to a suction device and the second air opening element to a pump device, the pressure limiting device provides high flexibility and adaptability to different operating conditions. This configuration enables precise control of the air pressure within the device in a way that it effectively handles both negative and overpressure conditions. The specific design of the air-opening element for connection to the corresponding pressure generating unit contributes to the efficiency and versatility of the pressure limiting device by enabling seamless integration into different pressure systems and optimizing the performance of the entire system.

[0017] The present invention also relates to a system comprising a pressure limiting device, a negative pressure generating unit, particularly a suction device, and a suction hose element for connecting the pressure limiting device and the suction device in a flow technique.

[0018] The present invention also relates to a system comprising a pressure limiting device, an overpressure generating unit, in particular a pump assembly, and a pump hose element for connecting the pressure limiting device and the pump assembly in a flow technology. Attached Figure Description

[0019] Other advantages are illustrated in the following figures. Extended embodiments of the invention are shown in the figures. The figures, description, and claims contain a variety of combined features. Those skilled in the art can also practically consider these features individually and generalize them into other meaningful combinations. These are shown here: Figure 1 A schematic view of a system consisting of a pressure limiting device, a handheld machine tool, and a negative pressure generating unit. Figure 2 Side view of the pressure limiting device, and Figure 3 : Cross-section of the pressure limiting device. Detailed Implementation

[0020] Figure 2 and Figure 3 A pressure limiting device 10 configured as a pressure limiting adapter is shown, comprising a housing 12, a first air opening element 14, and a second air opening element 16. The first air opening element 14 is disposed on a first housing portion 18, and the second air opening element 16 is disposed on a second housing portion 20, which is different from the first housing portion 18. The pressure limiting device 10 includes an air pressure limiting unit 22 for limiting the air pressure of the pressure limiting device 10 by means of the first and second housing portions 18, 20 constituting the pressure limiting device 10.

[0021] The pressure limiting device 10 constitutes a technical component for limiting pressure, particularly overpressure and / or negative pressure, within a system to a predetermined maximum value to prevent damage caused by overpressure. The device 10 is designed to operate in systems with airflow. The pressure limiting device 10 comprises a housing 12 and a mechanism 28, the housing having an inlet 24 and an outlet 26 for airflow.

[0022] The first and second air opening elements 14 and 16 enable controlled entry and exit of airflow. The first air opening element 14 forms an inlet 24 through which air enters the pressure limiting device 10. The second air opening element 16 forms an outlet 26 through which air exits after pressure regulation. The air pressure limiting unit 22 controls the airflow and ensures that the pressure within the pressure limiting device 10 is maintained at a desired level. The two air opening elements 14 and 16 regulate the airflow into and out of the system. The first air opening element 14 is arranged coaxially with the second air opening element 16 on the side of the housing 12 opposite to the second air opening element 16.

[0023] The housing 12 of the pressure limiting device 10 consists of exactly two separate housing portions 18 and 20 extending along the longitudinal axis 30. The first housing portion 18 and / or the second housing portion 20 are rotatably supported relative to the longitudinal axis 30. The first housing portion 18 allows air to enter the pressure limiting device 10, while the second housing portion 20 allows air to exit the pressure limiting device 10. The arrangement of the air opening elements 14 and 16 on the different housing portions 18 and 20 enables efficient and controlled guidance of airflow through the pressure limiting device 10.

[0024] An air pressure limiting unit 22, used to limit the air pressure of the pressure limiting device 10, constitutes a component or assembly within the pressure limiting device 10. It is configured to limit the air pressure to a predetermined maximum value, thereby preventing overpressure. The air pressure limiting unit 22 is configured as a regulating valve. The air pressure limiting unit 22 is also configured to limit negative pressure.

[0025] The air pressure limiting unit 22 has a third air opening element 32 for limiting air pressure, wherein the first air opening element 14 and the second air opening element 16 are larger than the third air opening element 32, in particular at least 300% larger. The first air opening element 14 is at least 50% larger and at most 80% smaller than the second air opening element 16. In addition to the main air opening elements 14, 16 that serve as inlet 24 and outlet 26, the air pressure limiting unit 22 also includes an additional, specially constructed third air opening element 32 for fine adjustment of air pressure. The size of this third air opening element 32 is significantly smaller than that of the first and / or second air opening elements 14, 16.

[0026] The air pressure limiting unit 22 has adjustable third and fourth air opening elements 32 and 34, which are formed by two housing portions 18 and 20 defining the first air opening element 14 and the second air opening element 16. The third and fourth air opening elements 32 and 34 are integrated components surrounding the housing portions 18 and 20 of the first and second air opening elements 14 and 16. Figure 3The housing 12 of the pressure limiting device 10 is configured such that it includes not only the main air opening elements 14, 16 (inlet 24 and outlet 26), but also integrates additional third and / or fourth air opening elements 32, 34. These third and fourth air opening elements 32, 34 are directly formed by the structure of the housing portions 18, 20 and are respectively constructed as recesses in the housing 12. The housing portions 18, 20 surrounding the first and / or second air opening elements 14, 16 are configured such that they respectively contain recesses for the third and fourth air opening elements 32, 34, which can be flexibly adapted to precisely regulate airflow. This adjustability is achieved by rotatable housing portions 18, 20, in order to change the size of the openings defined by the third and fourth air opening elements 32, 34 or to adapt the position of the airflow.

[0027] The fourth air opening element 34 is adapted to the third air opening element 32 and overlaps or covers each other in at least one open state, and / or does not overlap or cover each other in at least one closed state. Figure 2 or Figure 3 In the diagram, the pressure limiting device 10 is shown in its fully open state. Here, the third air opening element 32 is arranged directly below the fourth air opening element 34. Both openings completely cover each other. These openings are arranged vertically relative to each other, forming a common opening. The fourth air opening element 34 is configured and positioned such that it interacts with the third air opening element 32 in a specific manner. This adaptation is such that, in the open state, the two air opening elements 32, 34 are partially or completely above or overlap each other, thereby creating a common airflow passage that enables or enhances airflow. Conversely, in the closed state, the two air opening elements 32, 34 are arranged such that they do not cover or overlap each other, thereby interrupting or strongly restricting airflow.

[0028] The third and fourth air opening elements 32 and 34 are arranged between the first air opening element 14 and the second air opening element 16.

[0029] The first housing portion 18 is configured as a locking element, wherein the first housing portion 18 is rotatably supported and overlapped relative to the second housing portion 20. The first housing portion 18 is configured such that it is movably supported relative to the longitudinal axis 30 of the pressure limiting device 10 relative to the second housing portion 20. This rotatable support allows the first housing portion 18 to rotate relative to the second housing portion 20, thereby changing the position of the air opening elements 14, 16 and thus altering the airflow within the device 10. The overlapping arrangement of the two housing portions 18, 20 ensures that they are partially or completely overlapped in specific positions, enabling precise control of the airflow. By rotating the first housing portion 18, the user opens or closes the airflow by changing the overlap of the air opening elements 14, 16. The integration of the locking element into the housing 12 simplifies the structure and improves user-friendliness, as the operator can control the air pressure through simple rotational movement of the housing portion 18.

[0030] The first air opening element 14 is configured to connect the pressure limiting device 10 to the negative pressure generating unit 36, which is configured as a suction device. Figure 1 The second air opening element 16 is configured to connect the pressure limiting device 10 to a handheld machine tool 38, such as a grinder or electric hammer. Figure 1 ).

[0031] The housing 12 has a first interface section 40 disposed on a first housing portion 18, which includes a first air opening element 14. The housing 12 has a second interface section 42 disposed opposite to the first interface section 40 and on a second housing portion 20, which includes a second air opening element 16. The housing 12 has an overlapping section 44 on which the first housing portion 18 overlaps the second housing portion 20. The first interface section 40 has a maximum outer diameter smaller than the maximum outer diameter of the overlapping section 44 and the second interface section 42. Viewed along the longitudinal axis 30, the overlapping section 44 is disposed between the first and second interface sections 40 and 42. The overlapping section 44 has a section 46 that tapers radially in a direction toward the second interface section 40, which substantially brings the maximum outer diameter of the housing 12 from the maximum outer diameter of the first interface section to the maximum outer diameter of the second interface section 42.

[0032] The first interface section 40 has an unloading groove 50 on its outer side, which is constructed as a surrounding recess and arranged adjacent to the first air opening element 14. The unloading groove 50 forms an annular protruding connection area around the first air opening element 14. The unloading groove 50 is implemented as a radially outward cut and arranged parallel to the first air opening element. The first interface section 40 has a plurality of retaining ribs 52 arranged side by side and spaced apart from each other on its inner side. The retaining ribs 52 define the first interface section 40 from the inside and enable effective and flexible retention of the nozzle 54 of, for example, a handheld machine tool, especially a grinding machine 56, that extends into the first interface section 40. The retaining ribs 52 are constructed around a longitudinal axis 30 and extend radially toward the longitudinal axis 30. The retaining ribs 52 are constructed as inwardly protruding retaining ridges.

[0033] The second interface section 42 has two additional fastening openings 58 arranged adjacent to the second air opening element 16. The fastening openings 58 are constructed as recesses through the housing 12 or the second housing portion 20 and are spaced approximately 180° apart around the longitudinal axis 30. The fastening openings 58 are used to receive the suction device 80, particularly the suction hose 70 of an industrial vacuum cleaner, and are held by means of suitable fastening elements 72, particularly in a form-locking manner. Thus, the suction hose 70 can be pushed into the second interface section from the inside and held in or on the fastening openings 58 by means of the fastening elements 72, which are radially opposed to the longitudinal axis and movably supported.

[0034] The first housing portion 18 is supported relative to the second housing portion 20 by form-locking and / or force-locking. Specifically, the second housing portion 20 has a snap-fit ​​element 60 extending about a longitudinal axis 30, which protrudes radially outward relative to the second housing portion 20. The snap-fit ​​element 60 is angled in the insertion direction (angle surface 62) to achieve a snap-fit ​​connection in the insertion direction. The snap-fit ​​element 60 has a stop 64 (perpendicular stop surface 64) in a direction opposite to the insertion direction to increase difficulty or prevent the snap-fit ​​connection from loosening. In the connected state, the snap-fit ​​element 60 is provided for engaging with a built-in receiving groove 66 of the second housing portion 20 that surrounds the longitudinal axis 30. Currently, two snap-fit ​​elements 60 are provided, engaging with two receiving grooves 66. Viewed along the longitudinal axis 30, the snap-fit ​​elements 60 are arranged, particularly immediately in front of, and particularly immediately behind, the fourth air opening element 32. The fourth air opening element 32 is arranged between the two snap-fit ​​elements 60. The snap-fit ​​element 60 is arranged at a distance from the fourth air opening element 32.

[0035] Viewed along the longitudinal axis 30, the receiving slot 66 is arranged, particularly immediately in front of, and particularly immediately behind, the third air opening element 34. The third air opening element 34 is arranged between the two receiving slots 66. The receiving slots 66 are arranged spaced apart from the fourth air opening element 32.

[0036] The first housing portion 18 defines the first air opening element 14 around the longitudinal axis. The first and second air opening elements 14 are circular in cross-section. The second housing portion 20 defines the second air opening element 16 around the longitudinal axis. The second air opening element 16 is arranged on the side of the pressure limiting device 10 opposite to the first air opening element 14.

Claims

1. A pressure limiting device, particularly a pressure limiting adapter, comprising a housing (12), a first air opening element (14), and a second air opening element (16), wherein, The first air opening element (14) is arranged on the first housing portion (18), wherein the second air opening element (16) is arranged on a second housing portion (20) different from the first housing portion (18), characterized in that an air pressure limiting unit (22) for limiting air pressure is provided, especially by means of the first housing portion (18) and the second housing portion (20).

2. The pressure limiting device according to claim 1, characterized in that, The air pressure limiting unit (22) is configured to limit overpressure.

3. The pressure limiting device according to any one of the preceding claims, characterized in that, The air pressure limiting unit (22) has a third air opening element (32) for limiting air pressure, wherein the first air opening element (14) and / or the second air opening element (16) are larger than the third air opening element (32), especially at least 300%, preferably more than 400%, more preferably more than 600%, and even more preferably more than 1000%.

4. The pressure limiting device according to any one of the preceding claims, characterized in that, The air pressure limiting unit (22) has a particularly adjustable third air opening element (32), which is composed of two housing parts (18, 20), particularly the housing parts that limit the first air opening element (14) and / or the second air opening element (16).

5. The pressure limiting device according to any one of the preceding claims, characterized in that, The air pressure limiting unit (22) has a particularly adjustable fourth air opening element (34), which is composed of two housing parts (18, 20), particularly the housing part that limits the first air opening element (14) and / or the second air opening element (16).

6. The pressure limiting device according to any one of the preceding claims, characterized in that, The fourth air opening element (34) is adapted to the third air opening element (32), and / or covers or overlaps each other in at least one open state, and / or does not cover or overlap each other in at least one closed state.

7. The pressure limiting device according to any one of the preceding claims, characterized in that, The air pressure limiting unit (22), especially the third and / or fourth air opening elements (32, 34), is arranged between the first air opening element (14) and the second air opening element (16).

8. The pressure limiting device according to any one of the preceding claims, characterized in that, The air pressure limiting unit (22) has a locking element constructed separately from the third air opening element (32) for regulating the air pressure, wherein the locking element is constructed as the operator's hand, especially the fingers.

9. The pressure limiting device according to any one of the preceding claims, characterized in that, The locking element is configured as the first housing portion (18), wherein the first housing portion (18) is rotatably supported and arranged overlappingly with respect to the second housing portion (20).

10. The pressure limiting device according to any one of the preceding claims, characterized in that, The first air opening element (14) is configured to be connected to a negative pressure generating unit, particularly a suction device, and / or the second air opening element (16) is configured to be connected to an overpressure generating unit, particularly a pump device.

11. A system comprising a pressure limiting device according to any one of the preceding claims, a negative pressure generating unit, in particular a suction device, and a suction hose element, the suction hose element being used to connect the pressure limiting device and the suction device in a flow technique.

Images