1. Preparation before installation The pipelines before and after the ball valve are ready. The front and rear pipelines should be coaxial, and the sealing surfaces of the two flanges should be parallel. 　

The maintenance method for flange ball valves is as follows:When storing flanged ball valves, they should be protected from rain and moisture, and the flange cover should be tightly covered.　

The advantages of flanged ball valves are as follows:1. Simple structure, small size, and light weight.2. The fluid resistance is small, and its resistance coefficient is equal to that of pipe sections of the same length.　

Valves are an important component of large complete equipment, mainly used for cutting off, throttling, regulating pressure, and changing flow direction of pipeline media (materials, water, steam, air, oil, etc.).　

In recent years, domestic hardware industry valve enterprises have gradually shown a trend of outward development. 　

Gate valve is a common universal valve with a wide range of applications, mainly used in industries such as water conservancy and metallurgy. Its extensive performance has been recognized by the market.