How can we tell whether the compressor is sealed or non-sealed?
Manufacturers normally specify if a compressor is sealed against moisture and dust, and in many cases, you can tell the difference by simply visually inspecting the compressor. If you see vents, cracks, or holes in the motor housing, then it's not a sealed compressor.

So, does that mean if we can't see any vents, the compressor is definitely sealed from moisture and it's dust-resistant?
No, not always. Sealing a compressor for moisture- and dust-resistance is a very complicated process. It involves sealing all joints that are not necessarily visible to the
human eye.

Can a compressor that is moisture- and dust-resistant be operated safely underwater?
When a compressor manufacturer specifies that a compressor is sealed for moisture- and dust-resistance, it does not mean that the compressor is water- or dust-proof. Operating a compressor while it is submerged in water or sand is one fast way to throw away your money, and it's always obvious to us as to why the compressor fails when we get it back for warranty purposes.

What does the term maximum-rated working pressure mean? Why should we be concerned with a compressor's working pressure?
Maximum working pressure is the top-end pressure a compressor can be safely operated to without damaging the compressor or shortening the life of the compressor. Always look at the maximum-rated working pressure of the compressor you have purchased when choosing a pressure switch to use in your suspension system.

What about adjustable pressure switches? Are we able to use them on our suspension system?
We generally do not recommend the use of an adjustable pressure switch. This is simply because you may run the risk of setting the cut-out pressure at higher than the maximum-rated working pressure rated for your compressor, or for that matter, you may exceed the maximum-rated working pressure for your air supply tank. This could lead to a catastrophe that no one wants to imagine.

How do we find the maximum-rated working pressure of a compressor?
That's simple. Just ask your reputable compressor supplier
for the compressor manufacturer's compressor specifications. It will have that information on hand if it knows the product enough to be selling it.

Is the amp draw of a compressor something that we really need to be concerned with?
Yes, the lower the amp draw the compressor requires, the better the compressor is. As a rule of thumb, the maximum amp draw should be no more than 30 amps.

SOURCE
Viair Corp
26072 Merit Cir., Ste. 111
Laguna Hills
CA   92653
Dept. MT