The oil drain valve is used on the transformer oil tank to open and close the oil circuit. In the valve series, according to the actual needs of the transformer manufacturer, our company has also designed a dual-use valve. This kind of valve is installed at the lower part of the transformer for oil injection, and it can also be used for oil sampling. Note: The dimensions of each part of the middle 25, middle 50 and middle 80 dual-use valves are the same as those listed in Table 25, 50 and 80, but the difference is that an oil drain nozzle is added at the lower part of the structure and valve body, as shown in the figure.