Functions and Selection Guide for Pilot Valves in Industrial Control

Pilot operated valves are used in industrial control systems to precisely regulate fluid flow and pressure in various processes. Due to their high precision control and high flow handling capacity, pilot operated valves have become the preferred equipment in many industries.

Definition of Pilot Operated Valve

Pilot operated valve is a control device that operates a larger main valve through a small control valve. Usually, it uses pressure signals or electrical signals to adjust the state of the main valve, thereby controlling the flow of fluid. This design allows the system to be operated and adjusted more flexibly and efficiently.

Structure and Operation Mechanism

The pilot control valve is mainly composed of three parts:

Main valve: Directly responsible for controlling the flow of fluid in the system.

Pilot Operated Valve: A smaller valve that adjusts the opening and closing of the main valve in response to the needs of the system.

Induction Line: The pipe that connects the pilot operated valve to the system to monitor changes in pressure or flow and adjust the action of the main valve based on this information.

When operating, the pilot operated valve responds to changes in flow in the system. The adjustment of the pilot operated valve position changes the amount of fluid flowing into the main valve, thereby controlling the opening and closing of the main valve and achieving precise management of the entire system. This control method can effectively handle complex industrial processes and maintain the stable operation of the system.

Classification of Pilot Operated Valve

Pilot operated valves are generally divided into two main types: direct acting and pilot operated.

Direct Acting Valve: Its structure is simple, through the combination of spring and plunger to directly regulate the fluid flow. When the plunger moves under pressure, the valve opens and fluid passes through. When the pressure is relieved, the spring pushes the plunger back into place, closing the valve. This type of valve is suitable for occasions with low flow requirements, but its accuracy is not as high as the requirements of complex systems.

Pilot Operated Valve: This valve uses a small pilot operated valve to control the opening and closing of the main valve, usually operated by a solenoid or other actuator. This design enables more precise flow and pressure control and is suitable for large systems that require precision regulation.

Further, pilot-operated pilot operated valves can be divided into two types: internal pilot and external pilot. The internal pilot operated valve inserts the pilot operated valve into the main body, while the external pilot operated valve connects the main valve through a pipe.

How to Choose the Right Pilot Operated Valve

When selecting pilot operated valves, a number of key factors need to be considered to ensure that they meet the requirements of the specific application. First of all, it is necessary to ensure that the valve can work normally within the temperature range of the system, that is, it has good temperature adaptability. Secondly, the valve should be able to withstand the working pressure of the system, including the pressure value of the inlet and outlet, to meet the requirements of the pressure range. In terms of flow, the valve of the right specification should be selected according to the requirements of the system to ensure that it can handle the required flow in a specific time to avoid the problem of insufficient flow or excessive pressure drop. The choice of valve size is equally important and needs to match the piping size of the system to ensure optimal performance.

In addition, the selection of materials should be compatible with the fluid in the system and be able to withstand its temperature and chemical properties, while fluid compatibility requires that the valve design be able to adapt to the viscosity, temperature and chemical properties of the fluid. Finally, installation and maintenance are also factors that must be considered when selecting pilot operated valves, reasonable installation position and direction, as well as regular maintenance plans, can effectively extend the service life of the valve and ensure its long-term stable operation.

Typical Applications of Pilot Operated Valves

Pilot operated valves are widely used in many industries such as oil, gas, chemical, pharmaceutical, food and beverage, with typical applications including pressure regulation, temperature control, and flow management. In terms of pressure regulation, the pilot operated valve can maintain the pressure in the pipeline or tank within the set range even in the case of flow fluctuations by controlling the opening and closing of the main valve. In terms of temperature control, the pilot operated valve is combined with the temperature sensor to manage the temperature of the fluid in the system by adjusting the main valve to ensure that the desired temperature level is reached. In addition, the pilot operated valve also plays an important role in flow management, by cooperating with the flow meter, the state of the main valve can be flexibly adjusted according to actual needs, so as to maintain the specific flow rate in the system and ensure the efficient operation of the entire process.

Conclusion

As the core component of industrial control system, pilot operated valve provides a reliable solution for complex process control. Its variety of types and wide range of application scenarios make it an indispensable part of various industrial processes. Selecting the right pilot operated valve and proper installation and maintenance can greatly improve the efficiency and stability of your system.