QJ-20 Air Pressure Reducer for Lifeboats

Air Pressure Reducer for Lifeboats, Submarine - davit - launched - boat Pressure - reducing Valve QJ - 20

Model: QJ - 20 Air Pressure Reducer for Lifeboats

Measurement Range: 0 - 25 (MPa)

Rated Outlet Pressure: 0.8 (MPa)

Rated Flow: 200 (m³/h)

Structure: Two - stage - type Submarine - davit - launched - boat Pressure - reducing Valve

Working Principle: Reaction - type Submarine - davit - launched - boat Pressure - reducing Valve

What's the working principle of the two - stage submarine davit - launched - boat pressure - reducing valve?

1. **The first - stage pressure - reduction process**:

    - **Medium inflow and throttling**: The high - pressure medium enters through the inlet of the pressure - reducing valve. In the first - stage pressure - reduction chamber, there are specific throttling structures, such as narrow passages or small holes. When the medium passes through these throttling parts, as the flow area suddenly becomes smaller, the flow velocity of the medium increases. According to the principles of fluid mechanics, the increase in flow velocity leads to an increase in kinetic energy and a corresponding decrease in pressure energy, thus preliminarily reducing the pressure of the medium in the first - stage pressure - reduction chamber.

    - **Pressure balance and regulation**: The medium after the preliminary pressure - reduction acts on components such as pistons or diaphragms in the first - stage pressure - reduction chamber. These components will have corresponding displacements according to the changes in the medium pressure. For example, if the pressure is too high, the piston or diaphragm will be pushed, thus changing the throttling area so that the pressure can be regulated and controlled to a certain extent to maintain a relatively stable state, preparing for the second - stage pressure - reduction.

2. **The second - stage pressure - reduction process**:

    - **Further pressure - reduction**: The medium after the first - stage pressure - reduction enters the second - stage pressure - reduction chamber. The second - stage pressure - reduction chamber also has a similar throttling structure, but usually its throttling degree is more precise than that of the first - stage to achieve more accurate pressure - reduction. The medium undergoes the throttling effect again in the second - stage pressure - reduction chamber and the pressure drops further.

    - **Stable - pressure output**: The medium after the second - stage pressure - reduction flows to the outlet of the pressure - reducing valve through specific channels. In this process, some feedback mechanisms inside the pressure - reducing valve, such as diaphragm sensing and spring adjustment, will continuously adjust the position of the throttling components according to the changes in the outlet pressure to ensure that the outlet pressure remains within the set range. For example, when the outlet pressure has a rising trend, the diaphragm will sense the pressure change, and through the linkage device, the throttling component will reduce the flow area, increase the resistance, and thus reduce the pressure; conversely, when the outlet pressure decreases, the throttling component will appropriately increase the flow area, reduce the resistance, and allow the pressure to recover.

In general, through the two - stage pressure - reduction structure and the corresponding adjustment mechanism, the two - stage submarine davit - launched - boat pressure - reducing valve can gradually reduce the higher inlet pressure to a lower outlet pressure suitable for the submarine davit - launched - boat system and maintain the stability of the outlet pressure to meet the usage requirements of submarines under special working conditions.