So this is probably a stupid question, but at this point I am fully prepared to make myself look like an idiot rather than cough up more money.
Is there any benefit to purging your tank? You know, pulling the pin on the tank?
As in for what case…???
yeah if you want to blow rusty water all over.stale air works as good as fresh air. no need to purge the tank just drain the water off & you’ll be good to go.
So purging the tank pulls all the water out of the tank as well?
Oh yea, well most of it, crank the horns, does the same…
Pulling the pin on the tank will not drain water from your tank since it is no where near the bottom of the tank, that is a safety pressure release valve it is set to a certain psi in case your compressor fills the tank to a dangerous psi level that valve will pop open and release the air keeping the tank from exploding. if you want to drain the water from the tank you should have a drain that opens on the bottom of your tank.
A drain cock
version, hate to disagree with you bro , put that tank under pressure with concensation in it and pull the pin.done it and got rusty spray all over the back of my bed.yes the correct way is to drain tank with no pressure but to purge is with it under pressure. 
yeah you will get spray but unless that pin is on the verry bottom of the tank your not going to get all the water out of your tank… and i didnt say drain the tank with no pressure
Always use a safety valve… not because you can pull the pin - but because it will vent away excess pressure in case of a runaway compressor (pressure switch fails to shut off the compressor). You should NEVER need to pull the pin on a safety valve. You should drain the tank of excess moisture every so often by opening the drain cock.
i check my tanks always every 2 weeks…once i let my 5 gallon tank for 3 months and there was at least a good pint of water…in the tank.
Number12—when I first installed my setup I had a drain at the bottom of my tank and I tried it one time and got rusty water everywhere, so if you have the tank inside your vehicle, I don’t recommend a this. Now I have a separate solenoid valve plumbed to a length of air line to the bottom port of the tank, so now all I have to do is push the momentary switch that’s wired to it and it shoots all rusty water out of the tank(and outside the vehicle). Using a valve, a switch, a fitting, and some spare air line, this convenient purge/drain setup shouldn’t cost more than $40-$50.
Yeah but that would be bad for the valve right…
I’m guessing it’s not great for the valve, but again, I’m only using a $30 valve, so if it does crap out at some point, it’s an easy and inexpesive swap.
But it’s great to have the abitlity to blow that crap out of my tank(or purge all the air) at the push of a button from inside my truck,and it sounds pretty cool too(I’ve scared a few people just by giving a couple bursts @150psi through the valve)
I’ll try and get a few pics posted this specific setup soon.
I like this setup too. It may not be the best for the valve but since you either purge very seldom, or so often the discharge is relatively clean, (or maybe the valves are more durable than we give them credit) the valves seem to last.
If you do have problems with your valve aftr prolonged use and you bought a premium valve like an SMC you can take it apart fairly easily and clean any debris that does caught. It’ll most likely get stuck in the pilot if anywhere and its extremely easily to poke it out.
Mine doesn’t have a drain cock, just outlet (to solenoid), bike tire inlet, and safety valve.
Can I just turn my tank upside down, and pull the pin, to drain water? (While the tank has pressure)
I agree, most of the tanks we have are steel and not coated internally so under pressure condensate will naturally form inside the tank which could over time corrode the tank. I have a drain cock installed on the lowest point of my tank and I periodically drain the moisture out of it while its under pressure. Industrial applications have an automatic “spitter” valve which lets out a burst of air from the lowest point of the tank at a pre determined interval. Kind of sounds like a big rig with its periodic air drier spitting.