The foundry introduces what a small valve on the valve body is used for
The function of a small valve on the ball valve body is to relieve pressure, that is, to control the pressure inside the ball valve body through the manipulation of the valve. Valves are control components in fluid transportation systems that have functions such as cut-off, conditioning, diversion, avoiding reverse flow, stabilizing, diverting, or overflow pressure relief. The types and standards of valves used in fluid control systems, from simple globe valves to various valves used in chaotic self-control systems, are appropriately complex.
Valves can be used to control the activities of various types of fluids such as air, water, steam, various corrosive media, mud, oil products, liquid metals, and radioactive media. Valves are also divided into cast iron valves, cast steel valves, stainless steel valves (201, 304, 316, etc.), chromium molybdenum steel valves, chromium molybdenum vanadium steel valves, dual phase steel valves, plastic valves, non-standard customized valve materials, etc.
That's for relieving pressure. When the valve is closed, pressure will accumulate in the inner chamber of the valve body, and the pressure will be released by opening the valve. Ball valves equipped with this type of valve are generally fixed ball valves, and the sealing of fixed ball valves relies on the floating of the valve seat to seal. After removing the pressure from the inner chamber, there will be a pressure difference between the inlet and outlet ends of the pressurized valve seat, making it easier to seal. Usually, this is only installed on DBB (dual blockage and discharge) ball valves.