The type of valve that is filled or emptied by depressing a pin inside the valve. Commonly found on vehicles, motorcycles, and most moderately priced bicycles.
Infinite Air Duster!
This is my air duster. I don't like the nasty hydrocarbons they use in the normal product and didn't want to buy another disposable can, so I made this.
I drilled a hole in the top (1/8", with my dremel). NOTE: This goes directly AGAINST the WARNINGS on the label. I am not suggesting anyone try this. However, I drilled gently, used cutting oil and nothing bad happened. I also made sure that the can was empty (rubber banding the trigger open and leaving it for a long time works well).
The valve is just a schrader valve off of a dead bicycle tube--thus making it compatible with about any floor pump.
The valve is glued down, and lashed on with black hemp twine. The twine was then inundated with 2-ton 2-part epoxy to make a sturdy composite material. It's pretty burly.
When pumped up, the can gets noticeably warm (yay, Ideal Gas Law!), and should be used immediately. Otherwise, the high pressure air cools back to room temp, and comes out as really cold air. This leads to condensation problems. For similar reasons, I don't leave it charged.
EDIT: Read baitisj's comment below. I didn't make an instructable out of this because it is NOT safe. It is a pressure bomb waiting to explode. I built it because I have a good idea what the failure modes are, and think I'm immortal. There are plenty of dumb ideas on der intertron, this might be one of them.