Originally Posted by
X-LinkedRider
How do you think Air pumps work? Do you think there is 200 PSI floating around the atmosphere? A chamber collects more air than can fit through the valve and when the air is pushed it creates airflow at more than normal PSI ratings. End of story.
There's a difference between a pump, and a compressor. Most "pumps" are actually compressors, but an actual pump is not a compressor. Air pumps are made for blowing up things like inflatable alligators and just use an impeller to move air quickly.
A compressor on the other hand pulls air into a chamber, a valve closes to seal that chamber, and then the chamber is compressed. This is to say it takes 6 cubic inches of air at 14.7psi (atmospheric pressure approx) then compresses the chamber to 1 cubic inch making approx 90 psi. Some compressors go directly to the object (your tube) others go to a tank, then goto your tube.
Only flow rate is effected the diameter of valves, fittings or hoses. Not pressure.