Plastic plug caps for ball valves are used for high, medium, and low-pressure gate valves, stop valves, ball valves, butterfly valves, check valves, needle valves, process valves, drain valves, pressure-reducing valves, control valves, and other various valve products. The valve body materials include cast iron, stainless steel CF8, CF8M, CF3, CF3M, high-temperature steel, molybdenum-chromium steel, low-temperature steel, and various special materials. The actuation methods include manual, bevel gear, electric, pneumatic, electro-hydraulic interlock, and air-hydraulic interlock for opening and closing.