Installation Precautions for Electric Temperature Control Valves

In modern industrial production, the electric temperature control valve, as an important control device, is widely used in various scenarios that require precise temperature control. The correctness of its installation process directly affects the operational efficiency, service life, and overall safety and stability of the equipment and system. Therefore, understanding and mastering the key points and precautions for the installation of electric temperature control valves is crucial for ensuring the efficient operation of the equipment.

Preparations Before Installation

Adequate preparations before installing an electric temperature control valve are key to ensuring the smooth operation of the equipment.

1. Checking Nameplate Markings

Before installing the electric temperature control valve, it is essential to carefully check whether the nameplate markings on the valve match the design requirements. The nameplate typically indicates important parameters such as the valve model, specifications, working pressure, working temperature range, and type of medium. These parameters must be consistent with the actual operating environment and process requirements; otherwise, the valve may not function properly and could even lead to safety accidents.

2. Visual Inspection

Inspect the valve for any damage, deformation, or surface corrosion that may have occurred during transportation. Check that all components of the valve are present and that the connecting bolts are not loose. If any issues are found, they should be repaired or replaced promptly to ensure the integrity and reliability of the valve.

3. Calibration and Testing

For newly designed and installed control systems, to ensure that the electric temperature control valve operates normally during startup and that the system runs safely, the following items should be calibrated and tested:

Basic Error Limit: Check the error between the actual valve opening and the control signal to ensure it is within the allowable range.

Full Stroke Deviation: Measure the deviation of the valve's travel from fully open to fully closed to ensure it meets the design requirements.

Hysteresis: Check the position deviation of the valve when opening and closing under the same control signal.

Dead Band: Determine the sensitivity of the valve to the control signal to avoid inaccurate control due to an excessive dead band.

Leakage Rate: In applications with strict requirements, the sealing performance of the valve should be checked to ensure there is no leakage when the valve is closed.

If the control valve in the original system has undergone major repairs, in addition to verifying the above items, the packing gland and connection points of the old valve should also be checked for sealing performance to ensure good sealing.

Installation Environment Requirements

The suitability of the installation environment directly affects the performance and lifespan of the electric temperature control valve, so it is essential to strictly control the conditions of the installation environment.

1. Temperature and Humidity

The control valve is a field instrument that requires an ambient temperature range of -25°C to 60°C and a relative humidity of ≤95%. If the installation environment exceeds this range, it may lead to damage to the valve's electronic components or a decline in performance. For example, in high-temperature environments, electronic components may fail due to overheating; in high-humidity environments, the electrical parts may become damp, causing short circuits and other issues.

2. Vibration Protection

In areas with vibration sources, the valve should be installed away from the source of vibration or with added vibration protection measures. Vibration can cause internal parts of the valve to loosen, affecting its sealing performance and control accuracy. For example, the sealing surface between the valve core and seat may wear due to vibration, leading to leakage. Therefore, in environments with significant vibration, appropriate vibration protection measures should be taken, such as installing vibration pads or using flexible connecting pipes.

3. Protective Measures

If the valve is to be installed outdoors or in high-temperature environments, waterproofing and cooling measures should be taken. For example, a protective cover or sunshade can be installed to prevent rainwater ingress and direct sunlight. In high-temperature environments, insulating materials can be used to wrap the valve to reduce its operating temperature.

Installation Position and Orientation

The choice of installation position and orientation is crucial for the normal operation of the electric temperature control valve. Correct selection can effectively avoid problems caused by improper installation.

1. Vertical Installation

The control valve should generally be installed vertically to ensure smooth flow of the medium inside the valve and reduce sedimentation of impurities. Vertical installation also prevents valve core sticking or poor sealing due to gravity. If, for special reasons, the valve must be installed at an angle, the inclination should not be too large. When the inclination is significant or the valve itself is too heavy, additional supports should be added to protect the valve from deformation or damage due to gravity.

2. Installation Height

The pipeline where the control valve is installed should not be too high above the ground or floor. When the pipeline height exceeds 2 meters, a platform should be installed as much as possible to facilitate operation of the handwheel and maintenance. An excessively high installation position not only makes operation and maintenance inconvenient but may also increase stress on the pipeline system, affecting its safety.

3. Installation Direction

During installation, it is essential to ensure that the flow direction of the valve is consistent with the direction of the medium flow. There is usually an arrow on the valve housing indicating the direction of medium flow. If the installation direction is incorrect, it may cause the valve to malfunction or even get damaged. For example, reverse installation may subject the valve core to reverse impact from the medium, leading to valve core damage or poor sealing.

Pipeline Cleaning and Connection

Pipeline cleaning and connection are important aspects of the installation process of electric temperature control valves. The quality of these steps directly affects the service life of the valve and the operational efficiency of the system.

1. Pipeline Cleaning

Before installing the electric temperature control valve, the pipeline should be cleaned to remove debris and welding slag. Impurities in the pipeline may enter the valve and cause valve core sticking or damage to the sealing surface. Cleaning can be done using compressed air or clean water to ensure there are no residual impurities in the pipeline.

After installation, to ensure no impurities remain inside the valve, the valve should be cleaned again. When introducing the medium, the valve should be opened to prevent impurities from sticking to the valve core. During cleaning, appropriate cleaning agents or chemicals may be used, but it is essential to ensure that there are no residual cleaning agents in the pipeline afterward to avoid contamination of the valve and medium.

2. Pipeline Connection

The connection between the pipeline and the valve should be made using an appropriate method, such as flange connection, threaded connection, or welding. The connection should ensure good sealing to prevent leakage. For flange connections, suitable gaskets should be used, and bolts should be tightened evenly to prevent leakage due to loose bolts. For threaded connections, sealing tape or sealing compound should be used to ensure the seal of the threads. When welding, it should be done by a professional welder to ensure welding quality.

When connecting the pipeline, attention should also be paid to the support and fixation of the pipeline. The pipeline should have sufficient support to prevent uneven forces on the valve due to the weight or vibration of the pipeline, which could affect its normal operation. Additionally, pipeline stress should not be transferred to the valve, causing deformation or damage.

Electrical Installation

The electrical installation is a critical step in the installation process of electric temperature control valves. Its correctness directly affects the control accuracy and operational safety of the valve.

1. Electrical Equipment Installation Requirements

The electrical part of the electric temperature control valve should be installed according to relevant electrical equipment installation requirements. If it is an explosion-proof product, it should be installed in accordance with the relevant regulations. When installing electrical circuits, ensure that the insulation of the circuits is good to prevent electrical accidents due to leakage.

2. Cable Selection

For on-site wiring, H-type or other six-core or eight-core rubber installation cables with an outer diameter of approximately Φ11.3mm may be used. The selection of cables should be based on the electrical parameters of the valve and the operating environment to ensure that the cable's current-carrying capacity and insulation grade meet the requirements.

3. Safety Precautions

During use and maintenance, it is strictly forbidden to open the cover for repair or strike the explosion-proof surface in explosive environments. When disassembling and assembling, avoid damaging or scratching the explosion-proof surface. After maintenance, the original explosion-proof requirements should be restored. These measures can effectively prevent explosions caused by electrical sparks, ensuring the safety of the equipment and personnel.

Summary

The installation of electric temperature control valves is a complex and meticulous process involving various technical aspects and requirements. By conducting thorough preparations before installation, strictly adhering to the operational specifications for installation environment, position and orientation, pipeline cleaning and connection, and electrical installation, and carefully inspecting and testing the valve after installation, the normal operation of the valve can be ensured. This not only improves production efficiency but also guarantees the safety and stability of the equipment. Regular maintenance and upkeep are also essential for ensuring the long-term stable operation of the valve. Only in this way can electric temperature control valves fully leverage their advantages in practical applications and provide reliable temperature control support for industrial production.