【Application The oil flow indicator is a kind of device used for indicating the quantity of Oil flow in the transformer cooling system with forced oil circulation and supervising the operation situation of oil pump of cooling system with forced oil circulation, such as whether the rotation direction of oil pump is correct, the valve is opened, the conduit is blocked, etc .The indicator can initiate the alarming signal when the quantity of oil flow increases to the action oil flow quantity or decreases to the return oil flow quantity. TYPE:YJ-50/80/100/125/150】