Pneumatic up-opening and down-opening discharge valves are highly efficient discharge devices designed specifically for vessels such as reactors and storage tanks. They utilise pneumatic actuation to open the valve plug upwards (up-opening) or downwards (down-opening), thereby meeting material discharge requirements under various operating conditions. These valves are widely used in the chemical, food, pharmaceutical and metallurgical industries, and are particularly suitable for the precise control of materials requiring agitation or those with high viscosity.