Activation of the lead pressure reduction valve
A precursor pressure-relief valve is a valve that controls the movement of the main valve through a precursor valve, thus achieving precise regulation and control of the fluid pressure, which works as follows:
Overall structural basis
Lead pressure reduction valves consist of two components: the main valve and the lead valve. The main valve is primarily responsible for controlling the breakage and flow size of the fluid to regulate the pressure. The lead valve is used to sense changes in export pressure and to control the actions of the main valve according to the set values. In addition, components such as springs, film (or pistons) are usually available to assist in the regulation and control of pressures。
Specific work processes
Pre-commencement: before the pressure reduction valve is activated, the core of the main valve is closed or at its initial position by spring force, at which point the main valve is closed or less open to prevent flow passage. The lead valves are also closed, separating the upper cavity of the main valve from the export pressure。
Commencement and initial pressure reduction: when fluid enters the import of the pressure relief valve, the fluid pressure is on the core of the main valve. If the import pressure is higher than the pressure value set by the lead valve, the lead valve will be activated. Part of the fluid enters the upper cavity of the main valve from the import via a precursor valve, and, as the cavity of the main valve is larger than the area below the core of the main valve, the upper cavity pressure, according to the pascal doctrine, creates a downward force that drives the core of the main valve down, increases the opening of the main valve, and allows the fluid to flow from the import to the export and achieves initial reduction。
Pressures are stabilized: export pressures are gradually rising as fluids flow to exports. The export pressure functions through a feedback channel to the film (or piston) of the lead valve. When the export pressure reaches the set pressure of the lead valve, the pressure on the film (or piston) of the lead valve is balanced, and the lead valve begins to be smaller and reduces the fluid flow into the upper cavity of the main valve. The pressure on the upper cavity of the main valve has been gradually reduced, with the core of the main valve moving upwards, with the effect of spring power and differential import and export pressure, reducing the opening of the main valve, thus limiting fluid flow and maintaining a stable level of export pressure。
Dynamic balance maintenance: in the actual course of work, export pressures fluctuate with variations in factors such as downstream air use. When export pressure increases, the lead valves are further reduced, the main valves have increased their upper cavity pressure, the opening of the main valves has decreased, reducing export flows and reducing export pressure; on the other hand, when export pressure is reduced, the lead valves become larger, the upper cavity pressure of the main valves has decreased, the opening of the main valves has increased, and the flow of the main valves has increased, raising the pressure of exports. Through such a dynamic regulation process, a precursor pressure reduction valve can always keep the export pressure within the set limits and achieve precise pressure control。
Lead pressure reduction valves
