pneumatic tube length

Line length must be the same to both Cap Ports while lines to the Rod Ports can be a different length than Cap Port lines but equal length to both Rod Ports from valve.

The other problem I have encountered is when a cylinder is stroked completely to either end they can get stuck and not take off immediately when flow enters the ports. This can be overcome by mechaniclly stopping the cylinders before they bottom out metal to metal. This condition is most noticeable when the cylinders are oiled excessively.

i m very much convinced with ur ans. now let me know is it necessary that discharge flow at elecropneumatic valve (silencer side) suppose to be same. i feel that there is variation is it necessary to change it

Ideally it should be the same however, if it can't be avoided that they have different lengths, you could install speed control valves in ports of both cylinders then fine tune/adjust until they have the same timing.