Saltydog,
This setup is not intended to turn the D-500 into a regular compressor with a pressure switch that shuts off when the tank is full, although you could do that with a little ingenuity although It may burn that little compressor up over time.
It is just a way to smooth out the sputtering airflow that you get from diaphragm compressors. Some air will bypass the tank but it will be smoothed out in the end by the steady pressure from the tank itself.
It's a little hard to understand, but trust me it works.
HistoryInScale,
You are not necessarily trying to fill the tank, although it will get some air pressure in it, the idea is that the sputtering air from the compressor goes into the tank and collects somewhat in the tank and then goes back out to your airbrush "smoothed out" as compared to straight from the compressor which sputters badly because of the rubber diaphragm that pulsates in the compressor to produce the air.
Just mount the T-fitting on the top of the tank with the bottom of the 'T' downward. Then you will have two other ends at the top of the 'T' that are inline with each other correct? Now connect an airhose going from your compressor to one side of the 'T' and then connect your airbrush hose to the other side. The air will pump from the compressor into the tank and the tank will act as a buffer to smooth out the air. Try it and let us know if it works.
Mike
“Wisdom is the right use of knowledge. To know is not
to be wise. Many men know a great deal, and are all the greater fools
for it. There is no fool so great a fool as a knowing fool. But to know
how to use knowledge is to have wisdom. " Charles Spurgeon