Anyone here with knowledge on well pressure tanks? (aka air cannon time baby!)

[XOIIO]

Alright, so I used to have fun with a little air cannon I made using 3 inch PVC stepped down to a 3/4 inch (and then 1 inch) sprinkler solenoid, usually around 60 PSI, but I've been looking for a better solution, a bigger tank that can hold more pressure, and has more volume, and I was going to possibly get an oxygen tank from oxy acetylene welding at a scrap yard (might still if I want to do more pressure or this doesn't work out for hooking up a valve), and this popped up on kijiji for free.

A nice 33 gallon capacity tank for pressurizing well water. Now, apparently these have a bladder or something in them, I'm not sure if that will be an issue, and I'm not sure what I can get on it in terms of a release valve, idea I'd want a nice big 2 or 3 inch metal solenoid but that would be expensive and hard as hell to find, whereas a manual one will be easier to find and cheaper.

This will definitely be my project in the meantime though, I'll have to wait till I have money to buy some pipe and a non rusty valve, but the pressure gauge which is oil filled is in good shape. I'm also not sure if the small port at the bottom (surrounded by the red sticker) is where you fill it with air or not, I'll have to read some manuals, if not I have a tapping bit to put a snifter valve in.

Anyways, should be fun 

Pictures here since I don't want to clog the post up with them: http://imgur.com/a/JatoO#6

Also, seems to be this forum could do with a non-electronics project section, that would be neat.

[XOIIO]

Alright so that red port is the bladder, tried to hook to it and found it had pressure so I'll drain it for extra capacity, I took off the unknown device with wires on it and put a snifter valve instead, closed the two other valves and blocked the open end with the palm of my hand, a little bit of pressure rose, but then the pump stops consistently, unsure why, when connected to other stuff like the old air cannon and fire extinguisher I modified it does fine, so I am thinking there is a block or something going to the main tank, when I have some cash I'll take off the old plumbing and head to a hardware store to get new stuff that will fit. I will take it off ahead though (if I can find a pipe wrench around here) to see if there is a valve heading into the tank or not.

[johansen]

if you're good with a lathe you can make a coaxial valve.

run the barrel through the air tank (6 foot length is good), stopping about 3 inches from the bottom.

machine a groove in the end of the barrel, and stick an O ring in it.

machine a piston about .1 inches smaller diameter than the inside of the barrel, and make a pipe with two grooves inside it, for O rings to seal against the piston.
install the pipe in the tank.
when the piston is fully inserted, it will seal with the barrel, and air pressure will push it closed.
pressurize the chamber, pull the piston out, it will be forcefully pushed out, so you need a shock absorber to stop it.
whatever was in the barrel gets pushed out...

if you get creative, you can reload the barrel through the piston.

you can do all of the above with pvc pipe fittings without a lathe btw.

[XOIIO]

if you're good with a lathe you can make a coaxial valve.

run the barrel through the air tank (6 foot length is good), stopping about 3 inches from the bottom.

machine a groove in the end of the barrel, and stick an O ring in it.

machine a piston about .1 inches smaller diameter than the inside of the barrel, and make a pipe with two grooves inside it, for O rings to seal against the piston.
install the pipe in the tank.
when the piston is fully inserted, it will seal with the barrel, and air pressure will push it closed.
pressurize the chamber, pull the piston out, it will be forcefully pushed out, so you need a shock absorber to stop it.
whatever was in the barrel gets pushed out...

if you get creative, you can reload the barrel through the piston.

you can do all of the above with pvc pipe fittings without a lathe btw.

Man, I wish I had a lathe, that would be dreamy.

The solenoid is great for small stuff, I'll just need to go manual for bigger stuff.

I hope that you dont exceed the pressire rating of the tank and fittings. As a diver, ive seen what happens with both air and water when released either by acident or failure. Be carefull.. please.
 And using a water tank as air tank is no good idea.. so again, the forces inolved here is very powerfull and dangerus!
The  pressure, makes the oxygen self ignite and explode if there is only a fraction av
of carbonhydraits pressent. A tiny trace of oil on a fitting makes it  a bomb that goees of without a warning. Presuried air is dangerous.

Some videos..
Oil in a valve of a painballgun..



https://www.google.com/search?q=youtube+airtank+explode&rls=com.microsoft:nb-NO:MIE-Address&ie=UTF-8&oe=UTF-8&sourceid=ie7&rlz=1I7GGNI_noNO556


Sorry for my spelling...   ps.. ive been a diver for now 40 years, and seen the raw Power innvolved when Things og wrong With presurised air and water. It kills...

Yeah, my little air compressor (It's a car plug in one being powered by an old server power supply) can really only get to 80 PSI, and even then it struggles a lot, and that's with far far far faaaar less capacity in the tank, so there isn't any danger of over pressurizing it, and I definitely won't go right to 100PSI when I do have a better compressor, this is mainly for the extra air capacity.

[XOIIO]

Uhg, man.

Alright so I took off the "t" adapter, and as I thought, there was sediment in it, I tried pushing a small metal rod through but it seems to be solid with the stuff.

Anyways, I want tot take off that pipe and just get a new one, and I will probably have to clean out the elbow that is connected, but holy s**t it is in there tight. It's just plumbers tape, but I can't get the thing to move at all. I'm using the C clamp as a wrench since I don't have one that fits on hand (it usually works fine anyways, since there is a section with flat edges for a wrench, and man, I'm putting all my strength into it and it won't budge. Some percussive persuasion isn't working, and I don't really have room to pry with my crowbar. Once it's not 3:am (I'll have to wait till around 8 probably) I can whale on the clamp with the crowbar, but I don't even know if that will do it.

I also drained the diaphragm, that thing holds a massive amount of air, I ended up using said metal rod propped against a power supply to hold the valve open, it took like, four minutes to drain all the way.