Services water separators, checks meters for correct delivery and calibration, overhauls system components such as pressure regulating valves and excess valves, disassembles, adjusts, aligns, and calibrates gauges and meters or replaces them, removes and installs equipment such as filters and piping to modify system or repair and replace system component. Cleaning fuel tanks and distribution lines, removing corrosion and repainting surfaces, overhauling vacuum and pressure vents, floating roof seals, hangers, and roof sumps, and maintaining record of inspections and repairs.