Solenoid valve is integral part of Electro-Pneumatic Control system of engineering.This valve will control the supply of air to inlet or suction valve in load/unload operation of reciprocating air compressor .
Different types of solenoid valves are available in market.In Air Compressor Technology Normally open (N/O) or Normally Close (N/C) type solenoid valve are used to perform loading/unloading action.
Solenoid valve has three ports,these are
use of each port is as below
01)Inlet Port:-Impulse air supply through tube of Dia. not less than 12 mm from the air receiver through control filter connected to inlet port of solenoid valve
02)Outlet Port:-This port is also known as cylinder port.This is connected through,at least 6 mm Dia. Copper or Nylon tube to inlet (Suction) valve of the compressor.
03)Exhaust Port:-This port is for the escape of trapped air in the line.It should always kept open to the atmosphere.
Details of Normal Open & Normal Close Solenoid Valve.
A)Normal Open (N/O):-This type solenoid valve allow air supply to flow from inlet port to outlet (cylinder ) port,in de-energised or normal condition.When energised,due to change over in pressure switch contact stops the air supply.This type of solenoid valve are used for load/unload operation of air compressor.
B)Normal Close (N/C):-This type of solenoid valve does not allow air supply from inlet port to outlet port in de-energised or normal condition.When energised due to change over in contact of pressure switch allows air supply to flow through cylinder port.This type of solenoid valve is used in 5-step control panel for increasing and decreasing the area of clearance pocket during unloading/loading operation of Air Compressor.
Precautions to take for best performance .
01)For perfect functioning of the solenoid valve,always have an air filter,installed in the air line connected to solenoid valve.
02)Always see if the nut tightening the solenoid coil is intact.If loose,tighten the top nut.