hi all,
I have made a AT89c52 based fully automatic rectangular profile spot welding machine at Godrej. the machine uses 3 stepper motors for component indexing and spot welding gun rotation. and 2 solenoid operated pneumatic valves FESTO make jmfh 5 - 1/8 - 110 for vertical stroke of gun and high lip open close. Stepper motor driving I have tested and is working fine with AT89C52 since I am using expensive chopper drives which accept TTL signal and does the rest.
The valves needs a pulse of 110V A.C. for atleast 16ms for actuation. Now, my problem is what switching device would best serve the purpose an Ordinary mechanical relay or a Solid state relay, Currently I have made a board with PCB mount 12V mech relays and will be using separate supplies for relay drivers ULN2803A and Micro. Optocouplers in between micro and driver [ ULN 2803A ]. Snubbers in parrallel with valve solenoid. Free wheeling diode across relay coil and have avoided ground loops.
Before putting this configuration to use I wanted to know will the things go right or any chance of problem exist, as I am totally new with solenoid valves kindly help me with suggestions or comments.

Thank You All.