Safety Measures for Electric Control Valves

Ensuring the safety of electric control valves during design and installation is crucial. Leaks can occur at various points in the valve, such as the packing gland cover, flange seals, or at damage points like pinholes in the valve body. Leaks may not only happen when the valve is first used but can also develop over time, especially under extreme operating conditions like high temperature and pressure. When fluids pass through the valve, they may cause damage, with corrosive fluids potentially accumulating in cable trays, flammable fluids leaking into heated containers, or even dangerous hot fluids in alkaline solutions posing risks to operators. Therefore, safety requirements must be fully considered during the design, installation, and operation of electric control valves.

System Pressure and Safety Measures

Even after shutdown, system pressure inside the electric control valve may remain for some time. This means that effective safety measures must be in place to relieve system pressure during maintenance or disassembly. Particularly when cutting off the valve, accumulated hazardous liquids and high-pressure fluids can pose significant safety risks to equipment and operators. If not addressed in time, the release of high-pressure fluid could cause a catastrophic failure. Therefore, it is recommended to install vent and/or discharge valves on each side of the electric control valve to ensure safe pressure relief after the valve is shut. In cases where hazardous fluids accumulate, installing two vent and discharge valves is necessary.

Configuration of Vent and Discharge Valves

For valves that accumulate large amounts of high-pressure material, configuring two vent and discharge valves is particularly important. This design ensures that system pressure can be released smoothly and safely. In some cases, where only small amounts of material accumulate, pressure can be gradually relieved, ensuring that the fluid discharge process does not pose risks to equipment or personnel. It is especially important that the electric control valve is in an open position during discharge, allowing the fluid to exit safely.
For discharged gases that are hazardous, the venting pipeline must safely guide the gas away from the operating area. Even for non-flammable gases, appropriate venting systems should be used to prevent rust or other impurities from harming personnel during the discharge process. Therefore, choosing vent valves with flow-limiting capabilities is critical to prevent safety risks caused by improper operation.

Selection and Maintenance of Vent Valves

Choosing the right vent valve is key to ensuring the safe operation of electric control valves. If the fluid contains suspended solids, flow-limiting vent valves are prone to clogging. Thus, it is recommended to use larger discharge valves in the pipeline design to ensure smooth fluid discharge. Additionally, personnel operating flow-limiting vent valves must receive specialized safety training to avoid accidents caused by improper operation.

Design of Discharge Pipelines for Hazardous Liquids

The design of discharge pipelines is crucial when the fluid being discharged is hazardous. The pipelines must connect to safe locations to ensure the effective and rapid discharge of hazardous liquids, preventing harm to operators and the surrounding environment. During the design process, factors such as fluid properties must be considered, and appropriate materials and pipeline sizes should be chosen to ensure safe fluid discharge.

Safety Precautions and Operating Environment

During operation, electric control valves can become very hot due to heat, and appropriate safety measures must be taken to prevent burns to operators. This can include adding insulation materials or protective covers in high-temperature areas to ensure worker safety. Additionally, during installation, special care must be taken when handling threaded pipe fittings to avoid introducing sealing compound into the pipeline, which could affect the sealing performance. The amount of sealing compound used must be strictly controlled, and excess material, especially on the last two threads, should be avoided. PTFE sealing tape is recommended as an alternative to ensure good sealing performance.

Steam Pipeline and Pressure Fluctuations

For steam pipelines, effective insulation should be applied to upstream and downstream sections of the valve to minimize heat loss and improve energy efficiency. In areas with significant pressure fluctuations, it is advisable to install pipeline buffers. These buffers help stabilize pressure fluctuations, reducing the strain on the electric control valve and other equipment, thereby extending their service life.

Conclusion

 
Safety is the primary consideration in the installation and operation of electric control valves. From valve design to system installation and daily operation, a series of safety measures must be implemented to ensure operator safety and proper equipment functioning. By incorporating appropriate pressure relief devices, vent valves, and discharge pipelines, as well as providing necessary safety training and protective measures, accidents caused by improper operation or inadequate design can be effectively prevented. These comprehensive measures ensure that electric control valves operate safely and steadily under various working conditions.