Compressor/da

Hi

This may be long just warning to you.

I bought a new 60 gal, 7hp compressor with a max. output of 135 lbs of air. It is rated at 10.3 at 90 psi.

I have a problem maintaining air pressure at both the tank and the regulator when using my DA sander. The DA is rated at 8.3 cfpm at 90 psi. So you would think there would be no problem.

The minute I touch the sander to the metal and begin sanding there is a significant drop in rpm at the sander and at both the tank pressure and regulator. In less than 4-5 minutes I have a tank pressure of maybe 40 or 50 and a regulator pressor of 30 or so and both declining rapidly. I can never maintain 90 psi at the regulator to provide the air I need at the DA for optimum speed.

Whats wrong? This can not be normal can it?

Thanks for your help.