Among the automatic valves there are the diaphragm automatic control valves. The principles of these valves are based on the principle of balancing the corresponding pressure forces at the input and output and its control tank is used to control the hydraulic components of liquid.  Architecture within the structure and the type of mass movement and the presence of parts such as spring and diaphragm, which affect its power on the valve mechanism, allows automatic control of this type of valve.  In control valves, is often the task of controlling changes by a device called a hand-held connector or a pailot which is placed in the control circuit.

Piles or conductors are actually a variable slot that their operating basis is liquid pressure. Piles or conductors has different types which are developed according to the function description of the valve in the control circuit and the controlled main valve. Usually the hydraulic circuit valves are equipped with one or more types of pailots or conductors which allows the ability to perform different tasks on the lines. The following are some examples of types of automatic control valves with different piles.