The term oxygen service generally means using pure oxygen (oxygen concentrations of 95% to 100%), but the term is sometimes used more broadly to refer to any gas mixture containing more oxygen than air.

If you have properly maintained, used, tested and stored your cylinders in accordance with applicable regulations and manufacturer recommendations, the answer is no. If you continue following these proper procedures, your cylinders should provide many years of dependable service.

No. Special internal cylinder coatings are sometimes used with certain kinds of gases, but they have nothing to do with protecting a cylinder from tap water or any other kind of water, nor are they required or recommended for that purpose.

No. The field record of cylinders in use for many years shows no evidence of reduced service life from periodic hydrostatic testing with tap water.

No. Tap water of varying quality from all around the world has been used to hydrostatically test and retest aluminum and aluminum-lined composite cylinders for more than 30 years without harming cylinders or making them unsafe to use-provided, of course, that the cylinders have been properly dried after testing, as required by regulation.

Yes. Do not leave tap water or any other kind of water inside any aluminum or aluminum-lined cylinder-or any steel cylinder, for that matter.

DOT requires requalification (hydrostatic retesting and visual inspection) of all aluminum scuba tanks every five years, regardless of alloy.

After the introduction of eddy-current technology, Luxfer received reports of cracking in 6061-alloy cylinders. We accepted returns on about 1,200 of these cylinders to conduct extensive tests. Not a single cylinder was found to be cracked.

The easiest way is to check the original hydrostatic test date stamped on the cylinder crown.

Luxfer recommends taking your cylinder to an authorized Luxfer service center or to an inspector trained by Professional Scuba Inspectors, Inc. (PSI) or the Association of Scuba Service Engineers & Technicians (ASSET).

When properly used, eddy-current devices contribute significantly to early detection of hard-to-see sustained-load cracks.

A great deal of misinformation and exaggeration about SLC is attributable to rumors and inaccurate reports spread by word-of-mouth and the trade press, but especially by the Internet, where the proliferation of inaccuracies is widespread and essentially unregulated.