Solenoid valve is the most sensitive part used in loading/unloading of Air Compressor.many problems may arise due to unproper functioning of solenoid

valve.To avoid this the solenoid valve used in control system must work properly.To obtain best result from solenoid valve,it must installed in proper way.

so,first you have to know the installation procedure.

01)Solenoid Valve must be mounted inside the control panel.

02)Before starting the valve ensure that the air supply to the valve is filtered & lubricated.Even a momentary testing of valve with dirty contaminated air may

cause mal-functioning of valve for rest of working life.

03)Insure that adequate quantity of air supply is connected to the inlet port.A minimum air pressure of 15 to 20 PSIG is required to start with proper operation

because these are pilot operated valve.Air pressure to inlet port should not fall below required limit.

04)Connect electric supply marked on the solenoid valve without any loose connections.The solenoid is designed for the voltage drop plus or minus 10%.

Ensure 230Volt supply to coil.

05)Always take care to connect the cylinder port (outlet) of the valve, to suction valve.If the valve is tested without connecting this port to a closed chember

,then due to heavy pressure drop,the pilot mechanism will not have enough pressure to operate the internal mechanism & valve fail to function.

After proper installation, solenoid valve work properly.Due to long working span some fault may occure in solenoid valve.We will see what are the faults

& how to rectify that fault?

A) COIL CHATTERING:-

This may happen due to below reasons.

01)This type of valve requires proper voltage.A voltage drop or gain, more than 10 % affects fuctioning of coil.

02)A clean inlet air is required,if dirt entering the plunger housing,coil chattering problem starts.

03)A very low differential pressure range of load /unload will creat problem.Keep differential pressure range minimum 08 PSIG.

B)LEAKING VALVE:-

This may happen due to below reasons.

01)The valve is being tested with the cylinder port kept open to atmosphere.The defect can be rectified by connecting cylinder port to close chember.

(suction valve)

02)Inlet pressure is so low that the pilot mechanism can not be actuated.keep minimum air pressure above 15 PSIG.

03)Pipe line connected to any of the valve is so narrow that the cylinder connected to valve gets starved of air causing a severe pressure drop-hense starving

the pilot mechanism from getting minimum pressure.To remove this fault,connect the valve with adequate supply of compressed air.

04)Air leaking through the solenoid plunger housing when the coil is not energised.A replacement of plunger or plunger plug will rectify the problem.

05)Air leaking through the exhaust port,this defect may take place eighter due to dirt entering the valve or due to wear out of sealing components.

clean the valve or replace the sealing elements and rectify the problem.

prasanna

http://www.pnengineering.blogspot.com/