Comprehensive Summary Of Flanged Ball Valve Repair

Flanged Ball Valve are critical components of equipment and pipelines, and their maintenance must be integrated with the equipment and pipeline overhaul schedule. Refinery equipment undergoes a major overhaul annually, while thermal power plant generators undergo a major overhaul every two years. During these overhauls, valves on the equipment and pipelines awaiting repair are also overhauled or replaced.

The Refinery Equipment Maintenance and Overhaul Regulations, developed by the Ministry of Ag, Fuel, and Chemical Industries, specify the repair requirements for high-, medium-, and low-pressure valves in refineries serving oil, steam, water, and various gases with a nominal pressure of 16 MPa and a medium temperature below 550°C. These valves are divided into three categories.

1. Minor Overhaul: This includes cleaning the nozzle and cup, replacing packing, cleaning the valve stem and its threads, removing debris from the valve, replacing fasteners, and replacing the operating handle.

2. Medium Overhaul: This includes all minor repair tasks, including disassembly and cleaning of components, valve body repair, lapping of sealing surfaces, and valve stem alignment.

3. Major Overhaul: This includes medium overhaul tasks, including valve stem replacement, bracket repair, and spring and seal replacement.

The valve to be repaired should generally be disassembled for inspection and gasket replacement. Usually, medium and minor repairs of valves are more common.