The water jacket method is a widely used technique for testing the integrity and safety of gas cylinder particularly those used for storing high-pressure gases.
This method involves placing the cylinder inside a sealed chamber filled with water known as the water jacket. The cylinder is then pressurised with water to its designated test pressure. As the cylinder is pressurised, it expands, displacing the volumetric expansion of the cylinder, by comparing the permanent expansion (the expansion that remains after the pressure is released to the total expansion, inspectors can assess the cylinders structural integrity.
In conjunction with a thorough internal and external visual inspection, this method ensures that the cylinders are safe for continued use and helps prevent accidents due to cylinder failure.