A Pressure relief valve is called safety valve in some occasion, it really protect hydraulic system or other hydraulic components. The valve is like a guard keeping an eye on a doors. The guard should be flexible and strong enough to deal with different stages of alarm.

Hydraulic Directional Valve Symbols Introduction:
The spool mounted in the directional valves common known as sliding type often consists of lands as well as grooves. Most of the lands often block oil flow that flow through the body of the valve. The grooves also allow gas or oil to flow around the given spool at the same time through valve body. There are 2 fundamental positions of the directional control valve that are normal position and here the valve returns on the removal of the actuating force while often work in a positive position of a valve whenever the valve applies the actuating force. There is another valves class that has 3 or even more position that can be spring centered at the same time have 2 working position together with a normal position.

You need to know that directional control valves are classified according to their number of ports, the number of positions, the actuating methods and the type of spool. This will always help you make the best choice if you are planning of making the best decision when controlling them.

The following are different spool positions of schematic symbols that are commonly used in directional control valves.

 2-way directional control valvesdirectional-control-valve-position-and-way
The 2-way directional valve often has 2 ports normally known as inlet and outlet. Whenever the inlet valve is blocked in at-rest condition, the situation is common known as the “normally closed” (NC). This at-rest box or normal condition is one of the flow lines that often go in and out of it. This will always allow the flow of fluid better when compared to many other fluid flow options that people use in their machines.

 3-way directional control valves
The 3-way valve often has 3 working ports. The ports are an inlet, outlet, and tank (exhaust). A 3-way valve does not only supply an actuator with the fluid, but also allows fluid to make a return from it. This will always enhance the flow of fluid much easier when compared to a w-way directional control valves. This has been the main reason why the market now prefers it when compared to many other options that exist in many industries.

4-way and 5-way directional control valves
They also work just like the previously mentioned ones. However, you need to know more about them prior to making a decision of using them. This should help you make the flow of the fluid much easier than before. In conclusion, the above information will always enable you have more information that you need as you make that choice of learning how it directional control valves works.