According to U.S. Department of Transportation regulations, how often must scuba tanks be hydrostatically tested?

Scuba tanks must undergo hydrostatic testing every 5 years according to U.S. Department of Transportation regulations. This testing is crucial for ensuring the safety and integrity of the tanks used for storing compressed gases. The hydrostatic test involves filling the tank with water and pressurizing it to check for leaks and structural weaknesses. Over time, tanks can develop corrosion, fatigue, or other issues that may not be visible externally. Regular hydrostatic testing helps to identify these issues before use, thereby maintaining safety standards for divers. This requirement is in place to ensure that tanks are reliable and can withstand the pressures associated with diving activities.