When a datasheet says the max supply voltage for say a TL082 is +18v:
http://www.st.com/stonline/books/pdf/docs/2300.pdf
Does that mean you can power the op amp with +18v and -18v using 0v for the vref?? Or is it only just 18v and the usual 4.5v goes up to 9?
The pertinent info is in the plus & minus symbols in front (table 1 in your datasheet you've linked to) ...±18V - therefore it'll handle 36V max supply.
Possibly quite unneccesary to point out, but just in case: remember that Vref is "ground" as far as the opamp is concerned (as in: most opamps want a bipolar supply, and we usually fool them into buying a +/-4.5V supply with Vref at half supply or battery voltage, acting as ground level for the opamp....)
Now its very clear. Thanks