What pressure is the air stored insides a scuba tank?

Answer 1

Really as long as you want. You can store it at lower than 100 PSI for a long time, and you can store it in your basement. I really wouldn't store it with the cap off, but somehow you would need to mark it if you know it is almost at 100 PSI, because even the best divers cannot dive with 100 PSI safely. I wouldn't store it at full pressure, especially on a really hot day.

Answer 2

The amount of air (volume) that any solid container will hold is a function of pressure and temperature. the most common Scuba tank is an Aluminum 80 which stands for 80 SCF (standard cubic feet) which means the tank will hold 80 cubic feet of air at it's rated working pressure. Each cubic feet of air contains about 28 liters of air by volumn. So that would equal 2280 liters of air. A human lung contains about 1 liter of air (on average) when inhaling and so if the average human breathes roughly 12 respirations per minute, that Aluminum 80 would last about 187 minutes on the surface. Remember though that Boyles Law causes air to decrease in volumn as you increase ambient pressure. With each increase in ATMs you decrease your volume of air available to breath. At 99 feet or 3 ATMs the same tank would only contain 62 minutes of air. Each person is different and will consume more or less air.

Answer 3

Depending type of tank. (suitable to 200 or 300)

Regular 200Bar, but can be up to 300bar.