Pick out the wrong statement pertaining to a shell and tube heat exchanger.

• The minimum value of baffle spacing is 50 mm.
• The maximum value of baffle spacing is equal to the I.D. of the shell.
• The maximum unsupported tube span is generally about 75 times tube diameter, but is reduced to about 60 times for aluminium, copper & alloys of these.
• Disk and doughnut baffle is the most commonly used baffle.