could anybody help me how to fabricate a simple filling system using a PLC,motor,flow meter and valve..thanx?

Answer 1

A "simple" filling system would not need PLC control or a flow meter.
A 555 ic timing chip, a few switching components on a small circuit board and an electric solenoid valve on the supply.
If the flow and volume isn't consistent with time, add a float attached to a micro switch or an optical sensor to override the time setting.