Each pressure relief valve shall be a minimum of 3/4 inch (20 mm) and shall be equipped with a test lever. In addition, an automatic vacuum relief valve shall be installed on such tanks with a 24-mesh screen of bronze or stainless steel. The area of the screening shall be 50 percent greater than the opening it serves. All equipment of a hydropneumatic system shall be capable to withstand the designed working pressure.
Exception: This section shall not apply to pressurized captive air diaphragm/bladder tanks.