Reducing valves: the device and the principle of operation

Reducing valves are mechanisms that are designed to support low pressure in the withdrawn fluid flow. Most often, such tools are used in hydraulic drives, in which several devices are fed from one pump at a time. In this case, the pressure reducing valves normalize the pressure under which the liquid is supplied to all consumers, that is, there is no excessively increased or, conversely, reduced head pressure. This device can significantly reduce the risk of damage to the main supply lines of hydraulic fluid associated with excessive pressure inside the system.

This mechanism consists of the following parts:

• Tared spring;
• ball;
• A slide valve;
• damper;
• High-pressure connection;
• Internal cavities in the body for control of the spool.

Pressure reducing valve: photo and principle of operation

The liquid that is supplied from the main line enters the internal control cavity and, through a special annular gap between the valve and the housing, is fed into the hole associated with the entire system of the mechanism.

In the event that the pressure in the pipeline rises, the ball inside the mechanism also rises, and the pressure in the control cavity decreases to normal. This hole replenishes the working fluid from other cavities, as well as from the hole of a small section of the damper. The spool can regulate the pressure in only two lines, blocking the channel for supply of hydraulic fluid from the main system. Thus, this part increases the resistance of the passage of liquid, as a result of which the head in the cavity increases, which is determined by the force of the calibrated spring.

When the pressure in the system decreases, the slide valve under the action of the spring moves, thereby increasing the annular gap between the two cavities. Reducing valves in this case change the delivery head of fluid in one of the holes.

Based on this, we see that the pressure level remains unchanged at the output and is maintained by the device at the optimum level, regardless of the pressure of the hydroline and the flow rate of the working fluid.

What if the mechanism does not support a normal water supply?

Sometimes it happens that the pressure reducing valves are not able to provide all users with normal pressure. In this case, it should be adjusted. Each device, including the reduction valve VAZ 2109, has on the body a special adjusting screw, which affects the closing and opening of the valve in the system. If properly adjusted, you can achieve ideal values for the supply of working fluid.

Price

At the moment, the average cost of this device is 5-5.5 thousand rubles. The cheapest reduction valves can be purchased for 1200-1300 rubles. The most expensive options are about ten thousand.

Conclusion

So, we found out what the reduction valve consists of, and found out how the position of the slide valve and the ball affects the pressure in the internal cavities of the mechanism.