oil drain valve

1.Core Functions：It is mainly used to discharge insulating oil from the oil tank during transformer maintenance. Meanwhile, oil samples can be extracted through the sampling hole for oil quality testing. In case of accidents like transformer fires, the emergency oil drain valve can quickly discharge the oil into the oil sump and emergency oil reservoir. Cooperating with the gravel layer, it can isolate the fire and prevent the spread of the disaster. It has to bear the pressure of the oil column for a long time, and its sealing performance is crucial to avoid oil leakage and oil deterioration caused by contact with air, as well as potential safety hazards.

2.Structural Features：The common structure includes a flange connected to the oil tank, a valve body and a valve cover. The valve body is equipped with an oil drain hole and a sampling hole. Most of them adopt a double - sealing design, with sealing rings installed between the valve body and the oil drain plug, and between the valve body and the valve cover. Some butterfly - type oil drain valves consist of a valve seat, a valve plate, a handle, a rotating shaft, etc., and control the on - off state by rotating the valve plate. Ball - type valves include components such as a ball, a sealing seat and a valve stem, and ensure sealing through the floating ball under oil pressure.

3.Common Types and Parameters：It can be divided into cast aluminum, stainless steel, carbon steel and other types according to materials, and butterfly valves, ball valves and other styles according to structures. Common specifications include Φ29, Φ39, DN25, DN50, etc. The operating temperature is usually between -30℃ and 105℃, the nominal pressure is mostly 0.5MPa. The air leakage rate of some products is less than 1.33Pa·L/S within 10 minutes, which is suitable for media such as transformer oil.

4.Installation and Operation：It is generally installed at the lower part of the transformer oil tank, and the oil injection port of the emergency oil drain valve should face downward during installation. For operation, for butterfly valves, it is necessary to loosen the limit screws first, rotate the handle by 90° to open or close the valve, and then fasten the screws. Some emergency oil drain valves are equipped with a tempered glass oil - sealing diaphragm, which needs to be broken before opening the valve in case of fire. During installation, the flange surface must be flat, and the bolts should be tightened evenly to prevent leakage.