The invention comprises a method for controlling quality in a piping system, including a valve and a piping structure coupled to the valve. The method comprises the following: pressurize the piping structure with a gas at greater than sea-level pressure; seal the gas in the piping structure with the valve; determine whether the gas stays within the piping structure; determine that gas leaks from the piping structure; and identify the location of a leak from the piping structure. The invention further comprises a method for identifying a component. The method comprises the following: indicate identification information on a tag regarding the piping structure; and attach the tag to the piping structure.