Scuba tanks must be inspected to determine whether they can be sold for diving use or for scrap.
Scuba diving is a gear-intensive sport. Equipment upgrades often create the need to get rid of old gear. Most scuba gear is relatively straightforward to sell, but there is less guidance available for the sale of scuba tanks, which require periodic inspections. The condition of the tank will dictate whether it can be sold for diving or for scrap. To determine the status of an aluminum tank for diving is not a do-it-yourself activity, you will need to hire trained experts that use specific equipment for the task.
Determine the status of the tank
1. Determine the dates of the most recent visual inspection and hydrostatic test of the cylinder. The most recent visual inspection date will be on a sticker on the tank. If the inspection was more than a year ago, then it needs a new inspection.
2. The date of the most recent hydrostatic test will be stamped into the metal of the tank. A test needs to be performed within the last five years to be considered current.
3. A tank that has been condemned will be stamped with an “x” to indicate that it is no longer safe for diving.
4. By now you’ve identified the condition of the tank and need to decide to sell it (1) as is with or without current inspection and test, (2) after first updating the tank to a current test and inspection, and (3) as is for scrap metal.
Selling a tank For diving
5. A tank with a current visual inspection and hydrostatic test date can be filled and used for diving. To sell the cylinder, try online postings, newspaper classified ads, bulletin boards at dive shops in the area, or local dive clubs and mention the current status of the tests.
6. If the visual inspection is older than a year, then you’ll need to get the tank inspected at a local dive shop. The inspections are performed by a qualified Visual Inspection Program (VIP) technician, who checks the inside and outside of the tank for cracks, pitting and corrosion.
7. If the tank fails visual inspection from oxidation or corrosion, the dive shop can send the tank out to be “tumbled.” The tank is partially filled with a cleaning solution and small, rough particles that slough oxidation off of the inside of the tank.
8. If the hydrostatic test was performed more than five years ago, a new “hydro” is required to assess the structural integrity of the tank. During the hydro, the tank is filled with water and overpressurized in a water chamber.
Selling a tank for scrap
9. If you don’t want to go to the trouble of updating a tank with a current visual inspection and hydrostatic test or have a condemned tank, then you can sell it to a scrap metal dealer.
10. Take the cylinder outside or somewhere you can work without interrupting others. Emptying a cylinder will produce a loud hissing noise.
11. Empty the gas out of the cylinder by turning the knob to an open position. Leave it open until all the gas has drained out of the tank.
12. Remove the tank valve by unscrewing it from the tank neck. Keep the valve and sell or give it to a dive shop.
13. Deliver the empty cylinder without the value to a scrap metal dealer. They will typically pay by the pound for metal scrap.