In industrial pipeline systems, valves are important equipment for controlling the opening and closing of fluids, and their performance directly affects the safety and stability of the system. Among them, the opening and closing torque of the valve is one of the key parameters for measuring its operating performance. Accurate measurement of the opening and closing torque of the valve not only helps to evaluate the working condition of the valve but also provides a scientific basis for the selection of drive devices, optimization of the automation control system, and equipment maintenance.



One, What is Valve Opening and Closing Torque?



Valve opening and closing torque refers to the size of the rotational moment required during the opening or closing process of the valve. It is usually expressed in Newton meters (N·m). The size of this torque is closely related to the type, size, sealing material, medium pressure, temperature, and stem friction of the valve.



Two, The Significance of Measuring Valve Opening and Closing Torque



1. Selection basis: For electric, pneumatic, or hydraulic actuators, accurate opening and closing torque is the basis for selection.

2. Fault diagnosis: Abnormal torque values may indicate problems such as valve internal sticking, seal aging, or foreign body blockage.

3. Energy-saving optimization: By measuring the actual torque, the design of the driving system can be optimized to improve energy utilization efficiency.

4. Extend service life: Avoid equipment damage caused by overloading or improper operation, and extend the service life of valves and actuators.



Three, Measurement Methods



# 1. Manual Measurement Method

Applicable to small or low-pressure valves, the commonly used tool is the torque wrench. The operation steps are as follows:

- Install the torque wrench on the operating handle or valve stem of the valve;

- Apply force slowly and record the maximum torque value at the moment of valve opening and closing;

- Repeat the measurement multiple times and take the average value to reduce errors.



Advantages: Simple operation, low cost;

Disadvantages: There is a large amount of human error, not suitable for high-precision occasions.



# 2. Built-in Measurement Method of Electric Actuator

Modern electric actuators are usually equipped with torque sensors that can automatically record the torque change curve during the valve opening and closing process.



Advantages: High precision, continuous data, easy for automation monitoring;

Disadvantages: The equipment cost is high and needs to be calibrated regularly.



# 3. Torque Sensor Measurement Method

Use an independent torque sensor to connect with the valve, and cooperate with the data collection system for measurement.



Advantages: Suitable for various types of valves, can accurately measure dynamic torque;

Disadvantages: The system is complex and requires professional operation.



Four, Measurement Precautions



- Ensure that the valve is in a clean state before measurement, without impurities affecting;

- Test under normal working pressure and temperature conditions to reflect the actual working conditions;

- Record the torque values of both opening and closing directions to avoid omissions;

- Regular detection, establish a torque change trend chart for convenient status analysis.



Five, Conclusion



The measurement of valve opening and closing torque is an important link to ensure the safe operation of industrial systems. With the development of intelligent instruments and automation technology, torque measurement is advancing towards high precision, digitization, and intelligence. For engineering and technical personnel, mastering the correct measurement methods and analysis means not only helps to improve equipment management level but also lays a solid foundation for intelligent operation and maintenance.