The pressure releaser of the power transformer is actually a valve compressed with a spring. The valve has the function of instantaneously amplifying the starting force, and is used to release the instantaneous pressure increase in the oil tank of the power transformer and protect the oil tank of the oil-immersed power transformer. Avoid damage to the fuel tank. When the internal pressure of the oil tank is released to less than the spring pressure, the spring pressure will automatically close the valve to avoid excessive transformer oil overflow. When the pressure releaser operates, an alarm signal will be issued. The signal junction box should be kept dry so as to avoid false alarms when water is infiltrated and damp. At the same time, attention should be paid to the timeliness of the spring, and it should be checked regularly if necessary.

Pressure releasers are usually installed on top of oil-immersed power transformer tanks to reduce static pressure during normal operation. In order to prevent the hot oil from being sprayed on the equipment and personnel when it is in action, an oil guide pipe can be used to restrict the sprayed oil in the pipe and flow into the basic oil pool.

For large oil-immersed power transformers with more than a certain amount of oil, two pressure releasers should be installed.