In Reply to: how much pressure on the second stage ports posted by fishtank on July 13, 2006 at 11:30:24:

The intermediate pressure out of the first stage (the part attached to the tank) on most regulators is typically between 130 to 150 psi above the ambient pressure. Settings vary a bit between manufacturers as well as how they are set by the technician.

If you hook up your inflater hose to a tire and let it fill to the regulator pressure you may damage the tire or rim and possibly cause an explosion. However most industrial compressors put out 100 to 150 psi, the same pressure range as your first stage. Thus you can use a first stage like any air fill hose. Stop when the tire gets hard and check it, but be careful not to overfill.

The pressure coming out of the second stage (the part in your mouth) should be approximately ambient pressure. The second stage is designed to regulate it's output to the ambient pressure.