What happens when the inlet and outlet of the pressure reducing valve are reversed?

In this case, it becomes a shut-off valve.

When the inlet pressure is higher than the set pressure, it is normally closed.

When the inlet pressure is lower than the set pressure, it is normally open.

Relief valve. It is a valve that adjusts the inlet pressure to a certain required outlet pressure and relies on the energy of the medium itself to automatically maintain a stable outlet pressure. from fluid mechanics.

From the point of view, the pressure reducing valve is a throttling element whose local resistance can change, that is, by changing the throttling area, the flow rate and the kinetic energy of the fluid are changed, resulting in different pressure losses, so as to achieve the purpose of pressure reduction. Then, relying on the adjustment of the control and regulation system, the fluctuation of the pressure behind the valve is balanced with the spring force, so that the pressure behind the valve is kept constant within a certain error range.

1) Pressure regulation range: It refers to the adjustable range of the output pressure P2 of the pressure reducing valve, and the specified accuracy is required within this range. The pressure regulation range is mainly related to the stiffness of the pressure regulating spring.

2) Pressure characteristics: It refers to the characteristics of output pressure fluctuations caused by input pressure fluctuations when the flow rate g is a fixed value. The smaller the output pressure fluctuation, the better the characteristics of the pressure reducing valve. The output pressure must be lower than the input pressure—the fixed value is essentially unchanged from the input pressure.

3) Flow characteristics: It refers to the input pressure - timing, and the output pressure changes with the change of output flow g. When the flow rate g changes, the smaller the change in output pressure, the better. Generally, the lower the output pressure, the less it fluctuates with the change in output flow.

It reduces the high liquid pressure in the front line to the level required in the line behind the valve. The medium of transmission here is mainly water. Pressure reducing valves are widely used in high-rise buildings.

Areas where the water pressure in the urban water supply network is too high, mines and other occasions to ensure that the water pressure and flow rate are properly served at each point in the water supply system. In view of the fact that the leakage rate and waste degree of water are almost proportional to the water pressure of the water supply system, the pressure reducing valve has the effect of improving the operating conditions of the system and potential water saving, and its water saving effect is about 30% according to statistics.

There are many types of pressure reducing valves, such as diaphragm type and internal spring piston type. The basic principle of the pressure reducing valve is to reduce the water pressure by the local resistance of the flow channel in the valve to the water flow.

The principle of action of the pressure reducing valve is to reduce the water pressure by the local resistance of the flow channel in the valve, and the range of water pressure drop is automatically adjusted by the membrane connecting the valve disc or the inlet and outlet water pressure difference on both sides of the piston. The principle of fixed-ratio pressure reduction is controlled by the water pressure ratio of the floating piston in the valve body, and the pressure reduction ratio at the inlet and outlet ends is inversely proportional to the area ratio of the piston at the inlet and outlet sides. This type of pressure reducing valve works smoothly and without vibration; There is no spring in the valve body, so there is no worry about spring rust and metal fatigue failure; The sealing performance is good and does not leak, so it reduces the dynamic pressure.

when the water flows) and reduces the static pressure (when the flow rate is 0); In particular, the pressure is reduced without affecting the water flow.

Although there is a large head loss of water flow through the pressure reducing valve, it is still energy-saving overall because it reduces water waste and makes the system flow distribution reasonable, and improves the system layout and working conditions. When the medium is steam, it is advisable to choose a pilot piston pressure reducing valve or a pilot bellows pressure reducing valve. For ease of operation, adjustment and maintenance, pressure reducing valves should generally be installed on horizontal pipes.

It's like plugging it without installing a valve. It does not play the role of a decompression safety valve.

I don't know if it's right, the oil pressure is equivalent to a throttle valve when the oil pressure is small, and it becomes a check valve when the oil pressure is high.

P is the oil inlet, T is the oil return port, and A and B are the oil inlet or return port of the hydraulic actuator (hydraulic cylinder).

According to the number of channels controlled by the reversing valve, the hydraulic reversing valve is divided into: two-way, three-way, four-way and five-way, six-way and so on. The absolute activity of the valve body is applied to make the oil road traffic, block or change the direction of oil flow, so that the hydraulic actuating element and its driving mechanism can bear, end or change the direction of movement.