Originally Posted by PhilipW
As long as you're know the 3/4" is the inside diameter. Actually, it's more like .8125" ID for a regular threaded black pipe nipple from the home center.
You also have to make sure your ball valves are full port...you can purchase half port ball valves which will cut back on your air intake. I have 3 full port 3/4" ball valves, 1 shut, 1 full open and 1 half open to maintain 220ish. Good Luck!