Performance, types et principes de fonctionnement des vannes de régulation auto-opérées

The self-operated pressure regulating valve, also known as the self-operated control valve, is a novel type of regulating valve. As the name suggests, it does not require an external power supply or secondary instrumentation. Instead, it relies on the pressure and temperature of the medium flowing through the valve as the energy source to drive the valve's automatic operation. By utilizing feedback signals (pressure, differential pressure, temperature) from the valve's output end, these signals are transmitted through a signal pipe to the actuator, which drives the valve disc to adjust the valve's opening degree, thereby achieving the goal of regulating pressure, flow, and temperature.

Based on their structural functions, self-operated regulating valves can generally be classified into: self-operated temperature regulating valves, self-operated pressure regulating valves, self-operated flow regulating valves, and so on. These valves are capable of automatically regulating most fluid media. They effectively convert the inherent energy of the fluid medium into driving force to control the opening and closing of the valve.

When the fluid medium flows through the valve from the inlet, passing through the throttling action of the valve core and seat, it is converted into the outlet pressure. This pressure is then transmitted through a pipeline to the upper chamber, where it acts on the top tray, generating a force that balances against the counterforce of the spring. This balance determines the relative position of the valve core and seat, thereby controlling the outlet pressure.

When the outlet pressure increases, the force acting on the top tray also increases, causing the valve core to move closer to the valve seat. As a result, the gap between the valve core and seat decreases, increasing flow resistance and reducing the outlet pressure until the force acting on the top tray balances against the spring counterforce, thereby lowering the outlet pressure to the preset value. Conversely, when the outlet pressure decreases, the process operates in the opposite direction. This is the workflow of a self-operated regulating valve.

Compared to traditional control valves, self-operated regulating valves do not require external energy sources. Instead, they rely solely on the output signals of the medium being regulated to effectively adjust the properties of the fluid medium. This not only significantly reduces expenses on additional accessories but also minimizes energy consumption, aligning with national initiatives for energy conservation and emission reduction