Is it bad to leave air in the compressor?

[4_door-Johny]

I was reading my manual on mynew compressor and I was wondering do you really have to drain it out every time and refill it so it wont rust?

[hobie237]

the only danger is that water that is compressed out of the air collects in the bottom of the tank, eventually rusting it through

put a drain plug in the bottom and every once in a while pressurize it to 20 psi or so and blow out the water, then leave it empty overnight with the plug open so that you get all the water out

[sick1]

the water builds up during the run time because the air coming in is hot thus creating moister if you drain the water every night but still leave air compressed in it it will be fine

[hobie237]

actually, water vapor is simply squeezed out of the air as it is compressed, and the air gets hot from the energy imparted to it from the compression stroke (this is why diesel engines work, same principle) if it was because of hot air coming in, why does more moisture form over the winter? it has to do with the humidity


and chances are not enough water is going to build up over one day to justify draining it... wait and do it once a week

[Shiba-Kun]

Our large shop tank gets drained everyday. Our smaller one once a week. There's always moisture coming out, so if you use it alot I'd suggest draining it regularly.

[hobie237]

Originally Posted by Shiba-Kun

Our large shop tank gets drained everyday. Our smaller one once a week. There's always moisture coming out, so if you use it alot I'd suggest draining it regularly.

yes, and also proper oiling helps keep everything in order... if you have ever seen a rusty pressure vessel blow, (i have) you know the value of draining it... things arent pretty...

[02EXSILVER]

Propper oiling/replacement (depends on what type of comp.) are always a good idea. It's also nice to have an in-line dryer, both pre, and post stage. But if you don't, it's ok too. You should drain it atleast once a month. A post-stage air dryer isn't too expencive, and will help protect your tools too. You can even get them at HD, Lowes, and Sears. Don't forget to pick up tool oil too.

[justinedok]

I always drain my compressor when through with it. There is moisture in the air so eventually it will rust the inside of the compressor if you don't drain it.