Will my aluminum-lined composite cylinder have a shortened life from being hydrostatically tested with tap water?
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. This test is normally conducted quickly, and the cylinder only holds tap water for a few minutes. After the test, the cylinder must be dried. As long as this procedure is properly followed, there is no cause for concern.
Posted by Luxfer