Method for testing a function of a safety throttle of a valve, computing unit for carrying out the method, and valve and field device having the computing unit

Abstract

The invention relates to a method (100) for testing a function of an in particular passively designed safety throttle (14a; 14b) of a valve (10a; 10b) of a process plant by means of a computing unit (12a; 12b), in particular a computing unit of the valve (10a; 10b) or another field device (28a; 28b), wherein in a method step (106) a partial movement of a valve member of the valve (10a; 10b) is triggered, wherein during the partial movement of the valve member, at least one detected speed parameter of the valve member or of a transmission element (22a; 22b) of the valve (10a; 10b) connected to the valve member is provided, wherein in particular from the speed parameter a speed of the valve member can be determined, wherein in a further method step (108) the detected speed parameter and / or a speed of the valve member determined from the speed parameter during the partial movement is compared with a stored limit value of the speed parameter and / or of the speed of the valve member, wherein in the event that the limit value is exceeded, in a further method step (110) the outputting of a warning signal to a control system of the process plant, to a user and / or to an environment of the valve (10a; 10b) is triggered.

Description

[0001] November 6, 2025

[0002] Method for testing the function of a safety throttle of a valve, computing unit for executing the method, as well as valve and field device with the computing unit

[0003] State of the art

[0004] Technical equipment of any kind, including individual machines and entire process plants, poses certain hazards not only directly to operating personnel but also indirectly to the environment and thus to uninvolved persons. The nature and extent of these hazards depend on a multitude of factors, such as the characteristics of the respective technical equipment itself, as well as its operation. Against this background, legislators mandate the preparation of a risk and hazard analysis during the planning phase of such potentially hazardous technical equipment. By designing the technical equipment in accordance with legally established regulations, the identified risks and hazards can be reduced to an acceptable level during the intended operation of the technical equipment.

[0005] Particularly in the case of complex technical facilities, such as process plants, a process control system is required to establish and maintain an intended operating state. By correcting deviations from the intended operating state that remain within a limited range, a process control system contributes to the safe operation of a process plant. To ensure that even significant deviations from the intended operating state, exceeding the corrective capabilities of the process control system, do not lead to a safety-relevant event, process plants are additionally equipped with a safety system that is independent of the process control system.While the process control system, in addition to its primary task of process control, also contributes to the safety of the process plant to a certain extent, the sole task of the safety system is to return the process plant to a safe state in the event of safety-critical operating conditions. To this end, a safety system comprises at least one so-called safety-instrumented function, which is generally implemented in the form of a sensor, an actuator, and an electronic safety-related controller, also known as a logic module. The safety-related controller determines – independently of the process control system – the following:

[0006] Page 1 of 27 06.11.2025 based on the information supplied by the sensors, whether a safety-critical operating condition of the process plant exists and whether intervention by the safety system in the form of the execution of a safety-instrumented function, also referred to as a safety function, is required.

[0007] Control valves, especially pneumatically actuated control valves, in process engineering plants are equipped with safety functions designed to move the valve to a safe position in an emergency. Such a safety function typically must meet higher reliability requirements, such as functions for controlling a valve element or similar. In pneumatic actuators, this safety function is usually achieved by a spontaneously triggered rapid venting of the actuator's working chamber, releasing the stored air or other medium via a safety valve. Rapid venting of the working chamber eliminates the force opposing the actuator's return elements, usually springs, thereby moving the valve element to the safe position via these return elements. These return elements are generally quite robust.When the valve element is moved into a position via the return elements, the rapid displacement of the process medium can cause pressure surges within the process plant. These surges can potentially lead to significant damage to other components of the process plant, such as pumps, tanks, and / or other fittings. Such damage can necessitate extensive maintenance and / or repairs, resulting in considerable costs for the process plant. To dampen such movement of the valve element when moving into the safety position, safety throttles are provided, which are positioned either upstream or downstream of the safety valve. The safety valve is typically designed as a simple on / off valve.Depending on the system, process, and / or valve, the safety throttle can be adjusted to the necessary throttling effect to prevent pressure surges within the process plant when the valve element moves into the safety position. Switching the safety valve can be tested by actuating it using various methods. However, the safety throttle itself is usually not considered in these tests. This safety throttle can become clogged or blocked in other ways due to prolonged periods of inactivity during valve operation without triggering the safety function, thus preventing rapid venting of the working chamber.Furthermore, it is conceivable that, for example, damage to the safety throttle, such as internal damage or damage to the housing of the safety throttle, unintentional adjustment of the safety throttle and / or clogging of the safety throttle, could reduce the throttling effect of the safety throttle.

[0008] Page 2 of 27 06.11.2025 This means that pressure surges can no longer be prevented when the valve's safety function is triggered. In such a case, the entire process plant could be at risk.

[0009] Advantages of the invention

[0010] A method is proposed for testing the function of a safety throttle, particularly a passively designed one, of a valve in a process plant using a computing unit, in particular the valve itself. In one method step, a partial movement of a valve element of the valve is triggered. During the partial movement of the valve element, at least one detected velocity parameter of the valve element or of a transmission element of the valve connected to the valve element is provided. In particular, a velocity of the valve element can be determined from the velocity parameter. In a further method step, the detected velocity parameter and / or a velocity of the valve element determined from the velocity parameter during the partial movement is compared with a stored limit value of the velocity parameter and / or the velocity of the valve element.where, if the limit value is exceeded in a further process step, a warning signal is triggered and sent to a control system of the process plant, a user and / or the valve's surroundings.

[0011] A "passively designed" safety choke is understood to be, in particular, a choke designed without an actuator, specifically one free of moving components for throttling. The method for testing the function of the safety choke can be carried out using the computing unit. Preferably, the function of the safety choke is designed as a throttling of a medium flowing through it. More preferably, the function of the safety choke is designed as a throttling effect of the safety choke itself.A "partial movement" of the valve element is preferably understood to mean a movement of the valve element along and / or around an axis that occurs over a distance and / or an angular range which differs from a maximum traversable distance, in particular a maximum stroke, and / or from a maximum traversable angular range, in particular a maximum positioning angle, of the valve element, and is preferably smaller than these. Preferably, the partial movement is triggered such that the valve element performs the partial movement in an end position other than a fully closed position of the valve, in particular at a distance from it.

[0012] Page 3 of 27 06.11.2025 a valve seat of the valve, terminated. This can advantageously prevent the unintentional generation of a pressure surge within the system during partial movement.

[0013] Preferably, the velocity parameter of the valve element or the transmission element is provided via a sensor of the valve or an accessory of the valve or for the valve. In particular, the velocity parameter of the valve element or the transmission element is detected via a sensor of the valve or an accessory of the valve or for the valve. A "velocity parameter" of the valve element or the transmission element connected to the valve element is understood to mean, in particular, a parameter that describes a velocity of the valve element or from which a velocity of the valve element can be determined. The transmission element can be designed, for example, as an actuating rod, as a pneumatic unit, such as the working chamber, or as a drive rod of the valve. Preferably, the velocity parameter of the valve element or the transmission element is...The transmission element can be defined as a pressure in a working chamber operatively connected to the valve element, as an elapsed time for a measured or predetermined distance of the valve element during partial movement, as a position of the valve element, preferably relative to a start and / or reference position, or as the velocity of the valve element, preferably within a specific range of the partial movement and / or as the maximum velocity reached during the partial movement. It is conceivable that more than one velocity parameter is provided and used to test the function of the safety throttle.Preferably, in an embodiment in which the speed of the valve element is compared with a limit value of the speed of the valve element, in a process step of the process, preferably by means of the computing unit, the speed of the valve element is determined via the provided speed parameter, preferably calculated or read from a stored calibration curve.

[0014] Preferably, in a process step, particularly during commissioning of the valve, the limit value of the velocity parameter and / or the velocity of the valve element is stored in the processing unit. Preferably, the processing unit compares the detected velocity parameter and / or the velocity of the valve element calculated from the velocity parameter during the partial movement with the stored limit value of the velocity parameter and / or the velocity of the valve element. Preferably, at least one value of the velocity parameter or a plurality of values ​​of the velocity parameter are provided when the velocity parameter is made available. Preferably, when comparing the

[0015] Page 4 of 27 06.11.2025

[0016] Speed ​​parameter with the respective limit value, one or more values ​​of the speed parameter are used.

[0017] Preferably, the warning signal is output to the control system of the process plant, the user, and / or the environment of the valve by means of the processing unit, in particular directly or indirectly via another output device of the plant, the valve, or the user. Preferably, the output signal is triggered by the processing unit via an electrical or electronic signal, preferably from the processing unit to the plant and / or the output device.

[0018] It is conceivable that, in a process step, if a further stored limit value of the velocity parameter or the velocity of the valve element is undershot, a warning signal is triggered in a subsequent process step, particularly by means of the processing unit, to a control system of the process plant, a user, and / or the valve's surroundings. This preferably allows for the detection of clogging of the safety throttle. This advantageously enables testing of a safety function of the valve enabled by the safety throttle.

[0019] Preferably, the partial movement of the valve element is triggered by controlling an electrical and / or pneumatic actuator of the valve via the processing unit. Preferably, when the partial movement is triggered via the actuator, either directly or via pneumatic and / or electrical control of a valve actuator, the valve element is moved by the valve actuator.

[0020] The inventive design of the method allows for the advantageously simple testing of a valve's safety function during operation, which is made possible in particular by the safety throttle. Testing of the safety throttle can advantageously be performed independently of disassembling the line containing the safety throttle.

[0021] Furthermore, it is proposed that the partial movement of the valve element be triggered such that, during this partial movement, the valve element moves from an open position to a position other than the closed state of the valve. This can advantageously prevent the unintentional triggering of a pressure surge, for example in the form of a so-called water hammer, along a pipe adjacent to the valve during testing of the safety throttle. This, in turn, can advantageously prevent unintended damage to the system. In particular, the valve element rests against a valve seat in the closed state of the valve. Preferably, the valve seat is located in the closed state of the valve.

[0022] Page 5 of 27 06.11.2025 in a closed position of the valve seat. In particular, the valve element is arranged at a distance from the valve seat of the valve in the open position. Particularly preferably, the partial movement is triggered such that the valve element moves exclusively in one direction during the partial movement. Particularly preferably, the partial movement is triggered such that the valve element moves exclusively from a starting position of the valve element for the partial movement towards a position of the valve element when the valve is closed, or towards the closed position of the valve element.Preferably, the partial movement is triggered such that the distance traveled and / or the angle swept during the partial movement is at most 50%, preferably at most 40%, and particularly preferably at most 30%, of the maximum possible distance traveled, in particular a maximum stroke, and / or of the maximum possible rotation angle of the valve element. Particularly preferably, the partial movement is triggered such that the position of the valve element at the end of the partial movement is at least 10%, preferably at least 20%, and particularly preferably at least 30% of the maximum possible distance traveled, in particular a maximum stroke, and / or of the maximum possible rotation angle of the valve element, spaced from a fully closed position of the valve element or a position in a closed state of the valve.Preferably, the partial movement is triggered in such a way that at each point in time of the partial movement, the position of the valve element is spaced at least 10%, preferably at least 20% and particularly preferably at least 30% of a maximum traversable movement distance, in particular a maximum stroke, and / or a maximum traversable rotation angle of the valve element from the fully closed position of the valve element or the position in a closed state of the valve.

[0023] Furthermore, it is proposed that the partial movement of the valve element be triggered such that the valve element moves from a substantially fully open position during the partial movement. An advantageously large stroke range can be provided for the partial movement of the valve element. Moreover, this allows for a uniform starting point for the partial movement when testing the safety throttle in several time-spaced test procedures, which particularly improves the comparability of the test procedures and thus enables better diagnostics. In particular, the valve element is arranged at a distance from the valve seat in the substantially fully open position. Preferably, the valve element is arranged at the maximum possible distance from the valve seat in the substantially fully open position during valve operation.

[0024] Page 6 of 27 06.11.2025

[0025] Furthermore, it is proposed that a motion test of the valve be triggered in a process step prior to initiating the partial movement. This can advantageously prevent the valve from breaking free from a stuck position at the beginning of the partial movement, which could distort the velocity parameter recorded for the test. For example, the valve element may become stuck in the same position after a prolonged period of inactivity, requiring a higher force to overcome static friction. The presented motion test ensures that the valve element can be moved into the partial movement from a movable and preferably unaffected state. For example, the motion test is designed as a partial stroke test of the valve. However, other configurations of the motion test are also conceivable.Preferably, the movement test is triggered such that the valve element is moved from a rest position during the test. More preferably, the test is triggered such that the valve element is moved only a portion of its maximum possible range of motion. More preferably, the test is triggered such that, during the test, and particularly at any given time, the valve element is positioned at least 10%, preferably at least 20%, and most preferably at least 30% of its maximum range of motion, in particular its maximum stroke, and / or its maximum rotation angle, from a fully closed position or a closed position.Preferably, the valve's motion test is triggered by controlling the valve's electrical and / or pneumatic actuator via the processing unit. It is conceivable that the motion test is triggered by a separate control system for the system and / or the valve. Preferably, when the partial movement is triggered, the valve element is moved by the actuator, either directly or via pneumatic and / or electrical control of the valve drive. Preferably, the partial movement of the valve element is triggered within a maximum time interval, particularly a predefined one, before the end of the motion test. Preferably, the maximum time interval before the end of the motion test is at most one week, more preferably at most one day.

[0026] Furthermore, it is proposed that during the motion test, at least one condition parameter for the partial movement, in particular a starting position of the valve element, an end position of the valve element, and / or a distance to be traveled, be determined, especially by means of the computing unit. An advantageous range for the partial movement can be identified during the motion test. This allows for an advantageously precise test procedure.

[0027] Page 7 of 27 06.11.2025

[0028] Safety throttles are enabled, particularly since the movement of the valve element during the partial movement can advantageously proceed without interference due to the previously identified condition parameter. A "condition parameter for the partial movement" is understood to be, in particular, a parameter that at least partially describes the partial movement and preferably determines and / or specifies a behavior of the valve element during the partial movement. Preferably, one or more velocity parameters of the valve element or the transmission element, recorded during the movement test, are provided for determining the at least one condition parameter. Preferably, the at least one condition parameter for the partial movement is determined as a function of the velocity parameter(s) of the valve element or the transmission element recorded during the movement test.Alternatively or additionally, it is conceivable that at least one condition parameter for the partial movement is determined as a function of the valve element's position at the beginning, during, and / or at the end of the movement test. For example, it is conceivable that the valve element's position at the end of the valve's movement test is used as the valve element's position at the start of the partial movement via the condition parameter, with the condition parameter being configured as the starting position for the partial movement.

[0029] Furthermore, it is proposed that the partial movement of the valve element is triggered by a setpoint signal specifying a target velocity of the valve element, where the target velocity of the setpoint signal is greater than a stored expected velocity of the valve element. This advantageously enables smooth movement of the valve element during the partial movement. In particular, unwanted jerking of the valve element during the partial movement can be advantageously prevented. This allows for an advantageously accurate determination of the velocity parameter. Preferably, the expected velocity of the valve element is determined as a function of a valve type, in particular a valve actuator, a nominal valve diameter, or the like, and is preferably stored in the processing unit.In particular, the setpoint signal is designed as a signal that specifies a setpoint for a position of the valve element and / or triggers a movement of the valve element to the setpoint for a position of the valve element.

[0030] Furthermore, it is proposed that in a process step, depending on the detected velocity parameter and / or the velocity of the valve element determined from the velocity parameter, a time for a defined change in position of the valve element is determined, wherein the limit value is defined as a time for the defined change in position.

[0031] Page 8 of 27, dated November 6, 2025. A conveniently simple comparison of a determined value with the system's requirements for the valve can be achieved. Preferably, the time for the defined position change of the valve element is determined as a function of the detected velocity parameter and / or the velocity of the valve element calculated from the velocity parameter using the processing unit.

[0032] Furthermore, it is proposed that the partial movement of the valve element for testing the function of the safety throttle is achieved by controlling a positioner of the valve via the processing unit, wherein the positioner is configured to pressurize and / or vent a working chamber of a pneumatic actuator of the valve that is operatively connected to the valve element. This allows for a conveniently simple implementation of the method. Consequently, a significantly larger number of different valves suitable for testing the safety throttle can be achieved.

[0033] Furthermore, it is proposed that the partial movement of the valve element for testing the function of the safety throttle is achieved by controlling a control valve of the valve via the processing unit, wherein the control valve is configured to pressurize and / or vent a working chamber of a pneumatic actuator of the valve that is operatively connected to the valve element. This allows for an advantageously simple implementation of the method. Consequently, a suitably large number of different valves suitable for carrying out the method for testing the safety throttle can be achieved. Preferably, the control valve is designed as a solenoid valve. It is conceivable that the control valve is simultaneously used as the safety valve of the valve, with the control valve being, in particular, the safety valve itself.

[0034] Furthermore, it is proposed that at least one transmission of the at least one detected velocity parameter to the processing unit and the control of the valve's regulating valve by the processing unit to trigger the partial movement occur via a functionally safe connection. This enables an advantageously reliable and safety-oriented method, whereby a result of the safety throttle test can preferably be used for assessing plant safety, preferably without separate certification. Preferably, at least the transmission of the at least one detected velocity parameter to the processing unit and the control of the valve's regulating valve by the processing unit to trigger the partial movement are carried out using a functionally safe communication protocol, for example, a PROFIsafe protocol, in combination with another communication protocol acting as a black channel.

[0035] Page 9 of 27 06.11.2025

[0036] Preferably, the partial movement is triggered by the processing unit, preferably via the positioner and / or the control valve, through a functionally safe connection, preferably using a functionally safe communication protocol, for example a PROFIsafe protocol, in combination with another communication protocol acting as a black channel. To achieve a specified Safety Integrity Level (SIL), signal transmission must meet the respective requirements. For example, it may be necessary to ensure that the electrical signals are not corrupted due to electromagnetic interference or other influences; likewise, it may be necessary to ensure that no external electrical signals can be introduced or lost via an interface.Furthermore, it may be necessary, for example, to ensure that electrical signals are received in the correct sequence and that no delays or signal repetitions occur. To limit the probability of such errors to a level that meets the respective SIL requirements, a signal input / output involved in signal transmission within the safety circuit can also be designed to be functionally safe. The functionally safe design of a signal input / output may require the use of a suitable communication protocol. If a communication protocol or the respective signal input / output failed to detect the aforementioned errors, a safety system could not trust the received signals and the data transmitted with them.For example, if it could not be guaranteed that the probability of an external signal being introduced via an input remains below a certain acceptable threshold, a safety system would be unable to provide the required evidence of the resilience of a safety function for a specific safety integrity level. While it would obviously be simplest to handle all communication via functionally safe communication protocols, this could involve disproportionately high costs.Because only a specific part of the communication in process plants may need to meet particularly high reliability requirements, a standard communication protocol can generally be used in process plants. This protocol can then be supplemented with a more functionally reliable communication protocol, based on the standard protocol, only at the relevant points. In this case, the underlying standard communication protocol can be referred to as a "black channel." Preferably, the standard communication protocol could be based on Ethernet APL technology. However, other options are also possible.

[0037] Page 10 of 27 06.11.2025 any other conceivable communication protocol can be used; in particular, signal transmission on the physical layer (PHY) of such a communication protocol can be carried out, for example, via cable or wirelessly, but also using an optical fiber. The functionally safe communication protocol, based on a standard communication protocol, can use various measures to detect the aforementioned errors that can occur when the processing unit sends / receives electrical signals. For example, an incorrect receiving sequence of transmitted data packets can be ruled out by numbering the transmitted data packets; in this way, the loss of one or more data packets can also be detected.By assigning unique sender and receiver identifiers to data packets, misdirected electrical signals can be detected. Furthermore, a cyclic redundancy check (CRC) can be used to identify faulty components of a data packet resulting from electromagnetic interference or other influences. These and other security measures can be implemented, for example, in the PROFIsafe communication protocol. Using the PROFIsafe communication protocol together with any other communication protocol as the underlying "black channel" can result in a functionally safe signal input / output for the processing unit.

[0038] Furthermore, a processing unit, in particular the aforementioned one, of a valve or other field device of a process plant is proposed for carrying out an inventive method for testing the function of a safety throttle of the valve. The processing unit is designed to output a trigger signal to initiate a movement of the valve element, in particular a partial movement or a movement test, preferably to a control unit, in particular the positioner, of the valve or the control valve. Preferably, the processing unit is designed to process a measurement signal from the sensor, wherein the measurement signal is specifically intended to provide the detected velocity parameter.

[0039] It is advantageously possible to easily test a safety function of the valve during operation, which is made possible in particular by the safety throttle. Testing of the safety throttle can advantageously be carried out independently of disassembling any line containing the safety throttle. Preferably, the procedure can be advantageously performed entirely within the valve.

[0040] Page 11 of 27 06.11.2025

[0041] Furthermore, it is proposed that the computing unit be designed with functional safety in mind. This enables advantageously reliable and safety-oriented testing of the safety choke, whereby the test result can be used for assessing plant safety, preferably without separate certification. In particular, the functionally safe computing unit comprises at least one functionally safe signal input and / or at least one functionally safe signal output. Preferably, the functionally safe computing unit comprises more than one computing unit configured as a processor, FPGA, or the like, wherein at least two of the computing units of the computing unit are redundant to each other and preferably mutually synchronize, monitor, and / or correct each other.

[0042] Furthermore, a field device for a process plant is proposed, comprising a computer unit as defined by the invention and a communication unit for functionally reliable communication with the valve. It is conceivable that the field device could be configured differently from the valve itself. Preferably, the field device could be configured as an attachment for a valve, as a diagnostic device for the plant, as a switch for the plant, or the like.

[0043] The inventive design of the field device allows for advantageously high flexibility, whereby the method can also be carried out in older systems via the field device, preferably essentially independent of a valve type or a positioner of the valve.

[0044] Furthermore, a valve for a process plant with a safety throttle and a computation unit according to the invention is proposed. Preferably, the valve comprises the valve element. Preferably, the valve element is designed to open and close a throttle point formed over the valve, in particular a valve housing of the valve. In particular, the valve can be designed as an on / off valve, a control valve, a regulating valve, a safety valve, such as an emergency shut-off valve, or the like. In particular, the valve can be designed as a lift valve or a rotary valve. In particular, the valve element of the valve can be designed as a piston, a cage, a flap, a slide, or the like. Preferably, the valve comprises an actuator for moving the valve element. The actuator of the valve can be electrical, pneumatic, and / or hydraulic.

[0045] The valve's design according to the invention allows for advantageously simple testing of its safety function during operation, which is made possible in particular by the safety restrictor. Testing of the safety restrictor can advantageously be performed independently of disassembling any line containing the safety restrictor.

[0046] Page 12 of 27, November 6, 2025. It is preferable that the process be carried out advantageously entirely within the valve.

[0047] Furthermore, it is proposed that the valve includes a functionally safe connection between the processing unit and a sensor for detecting the velocity parameter of the valve element or the transmission element of the valve connected to the valve element. This enables advantageously reliable and safety-oriented testing of the safety throttle, whereby the test result can be used for an assessment of plant safety, preferably without separate certification.

[0048] Furthermore, a computer program is proposed, comprising instructions which, when the computer program is executed by a computer or a computing unit, in particular an inventive computing unit, cause it to execute the inventive procedure.

[0049] Furthermore, a computer-readable storage medium is proposed, comprising instructions which, when executed by a computer, cause it to execute the inventive procedure.

[0050] The inventive method, the inventive computing unit, the inventive field device, the inventive valve, the inventive computer program, and / or the inventive computer-readable storage medium are not / should not be limited to the application and embodiment described above. In particular, the inventive method, the inventive computing unit, the inventive field device, the inventive valve, the inventive computer program, and / or the inventive computer-readable storage medium may, to achieve a functionality described herein, comprise a different number of individual elements, components, units, and process steps than those specified herein. Furthermore, within the specified ranges of values, even values ​​within the stated limits shall be deemed disclosed and freely usable.

[0051] Page 13 of 27 06.11.2025

[0052] Drawings

[0053] Further advantages will become apparent from the following description of the drawings. The drawings illustrate two exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations.

[0054] They show:

[0055] Figure 1: a schematic view of a valve according to the invention with a safety valve, with a safety throttle and with a computing unit according to the invention, which executes a computer program according to the invention and has a computer-readable storage medium according to the invention, wherein the computing unit is configured to carry out a method according to the invention for testing a function of a safety throttle of the valve,

[0056] Figure 2: a schematic view of an exemplary sequence of the method according to the invention,

[0057] Figure 3: a schematic representation of an exemplary temporal sequence of a movement of an actuator of the valve according to the invention during the execution of the method according to the invention, in particular during a movement test and a subsequent partial movement to test the function of the safety throttle, and

[0058] Figure 4: a schematic view of a system consisting of a field device according to the invention of a process engineering plant with a computing unit according to the invention, which executes a computer program according to the invention and has a computer-readable storage medium according to the invention, and with a communication unit for a functionally safe communication with a valve, wherein the computing unit is configured to carry out a method according to the invention for testing a function of a safety throttle of the valve.

[0059] Page 14 of 27 06.11.2025

[0060] Description of the exemplary implementations

[0061] Figure 1 shows a schematic representation of a valve 10a of a process plant with a computing unit 12a. The computing unit 12a is used to carry out a method 100 for testing the function of a safety throttle 14a of the valve 10a, which is preferably passive. The valve 10a includes an actuator 16a, which is preferably a pneumatic actuator. The valve 10a includes a valve element (not explicitly shown in the figures) for opening and closing a throttle point. The valve 10a includes a safety valve 18a, which is provided for venting a working chamber of the actuator 16a. Preferably, the safety valve 18a is designed to vent the working chamber of the actuator 16a in a safety situation, thereby bringing the valve 10a into a safety state.The valve element moves into a safety position, which in particular means a closed state of valve 10a.

[0062] The valve 10a comprises a sensor 20a, which is arranged on a transmission element 22a connected to the valve member. The transmission element 22a is designed as a valve stem, which is specifically intended to transmit a drive force from the actuator 16a to the valve member. Alternatively, the sensor 20a may be arranged on the valve member or on another component of the valve 10a. The sensor 20a is designed to detect a velocity parameter of the valve member or of the transmission element 22a connected to the valve member. In the example shown in Figure 1, the sensor 20a can be configured as a stroke sensor, in particular a position sensor, as a velocity sensor, or as an acceleration sensor.However, other configurations of the sensor 20a are also conceivable, for example as a pressure sensor, wherein the sensor is preferably arranged at a different location on the valve 10a (illustrated by way of example in Figure 1). Alternatively or additionally, it is conceivable that the valve 10a comprises a plurality of sensors 20a, each of which is provided for detecting a velocity parameter of the valve element or of a transmission element 22a of the valve 10a connected to the valve element.

[0063] The valve 10a comprises a control unit 24a, which is configured in particular as a position controller. The control unit 24a is designed to regulate the position of the valve element as a function of a setpoint signal specified by a control system of the plant. Alternatively, for example, if the valve 10a is configured as a simple on / off valve, it is conceivable that the valve 10a merely comprises a control unit for actuating the actuator to open or close the valve 10a. The valve 10a comprises the computing unit 12a, which is configured in particular separately from the control unit 24a, preferably as an attachment of the valve 10a. Alternatively, it is conceivable that the computing unit 12a is integrated as part of the control unit 24a.

[0064] Page 15 of 27 06.11.2025. It is also conceivable that the computing unit 12a is designed separately from the valve 10a, for example as an attachment for the valve 10a or as part of an external field device of the system (see Figure 4).

[0065] The safety throttle 14a is arranged fluidically upstream of the safety valve 18a. The safety throttle 14a is fluidically arranged between the actuator 16a, in particular the working chamber, and the safety valve 18a. Preferably, the safety throttle 14a is fluidically arranged at a location between the actuator 16a, in particular the working chamber, and an exhaust outlet 26a of the valve 10a. The exhaust outlet 26a is designed to release a pneumatic medium, in particular compressed air, preferably at least during a safety-related venting of the actuator 16a, in particular the working chamber, and preferably in the event of a safety malfunction. It is conceivable that the safety throttle 14a is fluidically arranged downstream of the safety valve 18a and / or between the safety valve 18a and the exhaust outlet 26a of the valve 10a.

[0066] The processing unit 12a is connected to the control unit 24a to trigger movement of the valve element. The processing unit 12a is designed to output a trigger signal to the control unit 24a to initiate movement of the valve element. Preferably, the processing unit 12a is designed to process a measurement signal from the sensor 20a, wherein the measurement signal is specifically designed to provide a velocity parameter detected by the sensor 20a. The processing unit 12a is connected to the sensor 20a for the transmission of the measurement signal or the velocity parameter.

[0067] The computing unit 12a comprises a computer program containing instructions that, when executed by the computing unit 12a, cause it to perform the procedure 100 for testing a function of the safety throttle 14a. It is conceivable that the valve 10a comprises a computer-readable storage medium containing instructions that, when executed by a computer, cause it to perform the procedure 100 for testing a function of the safety throttle 14a.

[0068] In particular, the control unit 24a is designed to control the actuator via the safety valve 18a or via another pneumatic means, such as an electropneumatic pressure transducer, in order to trigger movement of the valve element. Preferably, the processing unit 12a is designed to control the control unit 24a via the trigger signal in such a way that movement of the valve element is initiated.

[0069] Page 16 of 27 06.11.2025

[0070] The processing unit 12a is configured such that, during procedure 100 for testing a function of the safety throttle 14a, a partial movement of the valve element is triggered. The processing unit 12a is configured such that, during the partial movement of the valve element, at least one detected velocity parameter of the valve element or of a transmission element 22a of the valve 10a connected to the valve element is made available. The sensor 20a is designed to detect the velocity parameter and make it available to the processing unit 12a. The processing unit 12a is configured such that, during procedure 100 for testing a function of the safety throttle 14a, the detected velocity parameter and / or a velocity of the valve element determined from the velocity parameter during the partial movement is compared with a stored limit value of the velocity parameter and / or the velocity of the valve element.The computing unit 12a is designed in such a way that if the limit value is exceeded, a warning signal is triggered to a control system of the process plant, a user and / or the environment of the valve 10a.

[0071] Figure 2 shows an exemplary sequence of procedure 100 for testing a function of the safety throttle 14a of the valve 10a. In a process step 102 of procedure 100, in particular during commissioning or maintenance of the valve 10a, especially the computing unit 12a, a limit value of the speed parameter and / or a speed of the valve element is stored in the computing unit 12a.

[0072] In a further process step 104 of process 100, a movement test of the valve 10a is triggered by means of the processing unit 12a. The movement test is, for example, designed as a partial stroke test. Preferably, the movement test is triggered such that the valve element moves from a rest position. Alternatively, it is conceivable that the movement test is triggered by means of the control unit 24a of the valve 10a, for example via a control system or a safety system of the plant, wherein, in particular, the partial movement is triggered by means of the processing unit 12a depending on the movement test. During the movement test, at least one condition parameter for the partial movement, in particular a starting position of the valve element, an end position of the valve element and / or a distance to be traveled, is determined by means of the processing unit 12a.In particular, a further velocity parameter of the valve element or the transmission element 22a connected to the valve element, recorded during the motion test, is provided, wherein the condition parameter is determined as a function of the further velocity parameter by means of the processing unit 12a. In particular, the further velocity parameter is recorded during the motion test by means of the sensor 20a.

[0073] Page 17 of 27 06.11.2025

[0074] The movement test of valve 10a is performed by controlling the control unit 24a of valve 10a, which is configured as a position controller, by means of the computing unit 12a. The control unit 24a is configured to pressurize and / or vent a working chamber of the pneumatic actuator 16a of valve 10a, which is operatively connected to the valve element. It is conceivable that the movement test is performed by controlling a control valve of valve 10a by means of the computing unit 12a. The control valve is configured to pressurize and / or vent the working chamber of the pneumatic actuator 16a, which is operatively connected to the valve element. In this case, the control valve is configured as the safety valve 18a. Alternatively, it is conceivable that the valve comprises a control valve and, additionally, the safety valve 14a for the safety function.

[0075] In a further process step 106 of process 100, the partial movement of the valve element is triggered by means of the computing unit 12a, in particular by controlling the control unit 24a. During the partial movement of the valve element, at least one velocity parameter of the valve element or of the transmission element 22a connected to the valve element, detected in particular by the sensor 20a, is made available. In particular, the velocity parameter or the velocity during the partial movement is detected by means of the sensor 20a. The partial movement of the valve element is triggered such that the valve element moves from an open position to a position other than a closed state of the valve 10a during the partial movement. The partial movement of the valve element is triggered such that the valve element moves from a substantially fully open position of the valve 10a during the partial movement.The partial movement of the valve element is triggered by a setpoint signal, which specifies a target speed of the valve element, whereby the target speed of the setpoint signal is greater than a stored expected speed of the valve element.

[0076] The partial movement of the valve element for testing the function of the safety throttle 14a is effected by controlling the control unit 24a of the valve 10a, which is designed as a position controller, by means of the computing unit 12a. It is conceivable that the partial movement of the valve element for testing the function of the safety throttle 14a is effected by controlling the control valve of the valve 10a by means of the computing unit 12a, wherein the control valve is designed to vent and / or purge the working chamber of the actuator 16a. Preferably, at least one detected velocity parameter is transmitted to the computing unit 12a, and the control valve / safety valve 18a of the valve 10a is controlled by the computing unit 12a to trigger the partial movement via a functionally safe connection.

[0077] Page 18 of 27 06.11.2025

[0078] In a further process step 108 of process 100, the detected velocity parameter and / or a velocity of the valve element determined from the velocity parameter during the partial movement is compared with the stored limit value of the velocity parameter and / or the velocity of the valve element by means of the processing unit 12a. Preferably, particularly when velocity is taken into account, the velocity of the valve element during the partial movement is determined by means of the processing unit 12a. It is conceivable that, depending on the detected velocity parameter and / or the velocity of the valve element determined from the velocity parameter, a time for a defined change in position of the valve element is determined by means of the processing unit, wherein the limit value is configured as a time for the defined change in position.

[0079] In a further process step 110 of process 100, if the limit value is exceeded, the computing unit triggers the output of a warning signal to a control system of the process plant, a user and / or the environment of the valve.

[0080] It is conceivable that in a further process step 112 of process 100, if a further stored limit value of the speed parameter or the speed of the valve element is undershot, a warning signal is triggered by the computing unit to the control system of the process plant, the user and / or the environment of the valve 10a.

[0081] Figure 3 schematically illustrates an exemplary sequence of movements of the actuator of valve 10a during the execution of procedure 100a, in particular during a movement test and a subsequent partial movement to test the function of the safety throttle 14a, in a flowchart 200a. The flowchart 200a shows a valve actuator position x 202a and a setpoint S 204a specified by the processing unit 12a over a period of time for the execution of procedure 100a. At time ti, a movement test is started and the valve actuator moves from a fully open position xo to a position xi. During the movement test, the setpoint 204a is changed such that the slope of the setpoint does not exceed a maximum possible speed of the valve actuator or a maximum possible change in the valve actuator position 202a over time.Preferably, the setpoint 204a is changed during the motion test in such a way that a speed of the valve element expected during the motion test or a change in the position of the valve element expected during the motion test does not exceed a predetermined limit speed for the valve element, in particular one stored on the computing unit 12a, in order to avoid pressure surges within the process plant.

[0082] Page 19 of 27 06.11.2025

[0083] Using the processing unit, the valve element is moved back to the fully open position xo at time t2 after the movement test. It is also conceivable that the movement to the fully open position xo is part of the movement test, for example, to determine the limiting speed for the valve element for subsequent movement tests or partial movements. At time E, the valve element has again reached the fully open position xo. At time t4, the partial movement to test the function of the safety throttle 14a is started. For this purpose, the setpoint 204a is set to position xi. The actuator attempts to move to position xi as quickly as possible.For this purpose, compressed air is released from the actuator 16a via the safety valve 18a and the safety throttle 14a, whereby the function of the safety throttle 14a is tested, in particular via the movement parameter, here for example the maximum rate of change of the valve element position 202a between time t4 and time ts. After the partial movement at time ts, the valve element is moved back to the fully open position xo.

[0084] The specified setpoint S 204a is preferably adjusted during partial movement for testing the function of the safety throttle 14a such that a change in the specified setpoint S 204a, especially at or after time t4, is greater than a possible velocity of the valve element. This allows the throttle function to be tested during partial movement.

[0085] Figure 4 shows a further embodiment of the invention. The following descriptions and the drawing are essentially limited to the differences between the embodiments, whereby with regard to identically designated components, in particular with regard to components with the same reference numerals, reference may also be made to the drawings and / or the description of the embodiment, especially Figure 1. To distinguish the embodiments, the letter a is appended to the reference numerals of the embodiment in Figure 1. In the embodiment of Figure 4, the letter a is replaced by the letter b in each case.

[0086] Figure 4 shows a system consisting of a valve 10b and a field device 28b with a computing unit 12b, wherein the computing unit 12b of the field device 28b is configured to perform a method 100 for testing the function of a safety throttle 14b of the valve 10b. The computing unit 12b is configured such that, during the method 100 for testing the function of the safety throttle 14b, a partial movement of a valve element of the valve 10b is triggered. The computing unit 12b is configured such that, during the partial movement of the valve element, at least one detected velocity parameter of the valve element or of a transmission element 22b of the valve 10b connected to the valve element is made available.

[0087] Page 20 of 27 06.11.2025. The valve 10b includes a sensor 20b, which is designed to detect the velocity parameter and make it available to the processing unit 12b. The processing unit 12b is configured such that, during procedure 100 for testing a function of the safety throttle 14b, the detected velocity parameter and / or a velocity of the valve element determined from the velocity parameter during partial movement is compared with a stored limit value of the velocity parameter and / or the velocity of the valve element. The processing unit 12b is configured such that, if the limit value is exceeded, a warning signal is triggered and sent to a control system of the process plant, a user, and / or the environment of the valve 10b and / or the field device 28b.The valve 10b shown in Figure 4 is essentially identical in construction to the valve 10a described in Figures 1 to 3. The valve 10b shown in Figure 4 differs from the valve 10a described in Figures 1 to 3 in that the processing unit 12b is designed separately from the valve 10b as part of the field device 28b of the process plant. Preferably, a connection between the field device 28b, in particular the processing unit 12b, and the valve 10b, in particular the sensor 20b and / or the control unit 24b of the valve 10b, is designed to be functionally safe. The field device 28b includes a communication unit 30b for functionally safe communication with the valve 10b, in particular between the processing unit 12b and the control unit 24b and / or the sensor 20b.

[0088] Page 21 of 27 06.11.2025

[0089] Reference sign

[0090] 10 valve

[0091] 12 computing units

[0092] 14 Safety throttle

[0093] 16 Drive

[0094] 18 Safety valve

[0095] 20 Sensor

[0096] 22 Transmission element

[0097] 24 control unit

[0098] 26 Exhaust air outlet

[0099] 28 Field device

[0100] 30 communication units

[0101] 100 procedures

[0102] 102 Procedure step

[0103] 104 Procedure step

[0104] 106 Procedure step

[0105] 108 Procedure step

[0106] 110 Procedure step

[0107] 112 Procedure step

[0108] 200 trend chart

[0109] 202 Valve element position

[0110] 204 Target value

[0111] Page 22 of 27

Claims

November 6, 2025 Claims 1. Method for testing the function of a safety throttle (14a; 14b), in particular a passively designed, of a valve (10a; 10b) of a process plant by means of a computing unit (12a; 12b), in particular of the valve (10a; 10b) or of another field device (28a; 28b), wherein in a method step (106) a partial movement of a valve element of the valve (10a; 10b) is triggered, wherein during the partial movement of the valve element at least one detected velocity parameter of the valve element or of a transmission element (22a; 22b) of the valve (10a;10b) is provided, wherein in particular a speed of the valve element can be determined from the speed parameter, wherein in a further process step (108) the detected speed parameter and / or a speed of the valve element determined from the speed parameter during the partial movement is compared with a stored limit value of the speed parameter and / or the speed of the valve element, wherein if the limit value is exceeded in a further process step (110) a warning signal is triggered to a control system of the process plant, a user and / or an environment of the valve (10a; 10b).

2. Method according to claim 1, characterized in that the partial movement of the valve element is triggered in such a way that the valve element moves from an open position to a position different from a closed state of the valve (10a; 10b) during the partial movement.

3. Method according to claim 1 or 2, characterized in that the partial movement of the valve element is triggered in such a way that the valve element moves out of a substantially fully open position of the valve (10a; 10b) during the partial movement.

4. Method according to one of the preceding claims, characterized in that in a method step (104) a movement test of the valve (10a; 10b) is triggered before the partial movement is initiated. Page 23 of 27 November 6, 2025 5. Method according to claim 4, characterized in that during the movement test at least one condition parameter for the partial movement, in particular a starting position of the valve element, an end position of the valve element and / or a distance to be covered, is determined.

6. Method according to one of the preceding claims, characterized in that the partial movement of the valve element is triggered via a setpoint signal which specifies a setpoint speed of the valve element, wherein the setpoint speed of the setpoint signal is greater than a stored expected speed of the valve element.

7. Method according to one of the preceding claims, characterized in that in a method step (108) a time for a defined change in position of the valve element is determined as a function of the detected velocity parameter and / or the velocity of the valve element determined from the velocity parameter, wherein the limit value is designed as a time for the defined change in position.

8. Method according to one of the preceding claims, characterized in that the partial movement of the valve element for testing the function of the safety throttle (14a; 14b) is carried out by controlling a positioner of the valve (10a; 10b) by means of the computing unit (12a; 12b), wherein the positioner is configured to vent and / or aerate a working chamber of a pneumatic actuator (16a; 16b) of the valve (10a; 10b) operatively connected to the valve element.

9. Method according to one of claims 1 to 8, characterized in that the partial movement of the valve element for testing the function of the safety throttle (14a; 14b) is effected by actuating a control valve (18a; 18b) of the valve (10a; 10b) by means of the computing unit (12a; 12b), wherein the control valve (18a; 18b) is designed to vent and / or aerate a working chamber of a pneumatic actuator (16a; 16b) of the valve (10a; 10b) operatively connected to the valve element. Page 24 of 27 November 6, 2025 10. Method according to claim 9, characterized in that at least one transmission of the at least one detected velocity parameter to the computing unit (12a; 12b) and control of the solenoid valve of the valve (10a; 10b) by means of the computing unit (12a; 12b) to trigger the partial movement takes place via a functionally safe connection.

11. Computing unit of a valve (10a; 10b) or of another field device of a process engineering plant for carrying out the method (100) according to one of the preceding claims for testing a function of a safety throttle (14a; 14b) of the valve (10a; 10b).

12. Computing unit according to claim 11, characterized by a functionally safe design.

13. Field device of a process engineering plant with a computing unit (12b) according to claim 1 or 12 and with a communication unit (30b) for a functionally safe communication with the valve (10b).

14. Valve of a process engineering plant with a safety throttle (14a) and with a computing unit (12a) according to claim 11 or 12.

15. Valve according to claim 14, characterized by a pneumatic actuator (16a) and a control valve (18a) for venting and / or de-venting a working chamber of the actuator (16a), wherein the safety throttle (14a) is arranged fluidically, in particular substantially directly, before or after the control valve (18a).

16. Valve according to claim 14 or 15, characterized by a functionally safe connection between the computing unit (12a) and a sensor (20a) for detecting the speed parameter of the valve element or of the transmission element (22a) of the valve (10a) connected to the valve element.

17. Computer program comprising instructions which, when the computer program is executed by a computer or computing unit (12a; 12b), in particular according to claim 11 or 12, cause it to execute the method (100) according to any one of claims 1 to 10. Page 25 of 27 November 6, 2025 18. Computer-readable storage medium comprising instructions which, when executed by a computer, cause it to execute the method (100) according to any one of claims 1 to 10. Page 26 of 27

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