Abstract: A liquid level valve for use in filling a liquid storage tank to control (in response to increased air pressure within the liquid level valve) the tank emergency loading valve which is held open by pressurized air.The liquid level valve has an air control cavity connected to the pressurized air and an actuating cavity which exhausts to the atmosphere and is disposed above the air control cavity and connected to it via an actuating passageway. An air control diaphragm divides the air control cavity into upper and lower portions and controls the flow of pressurized air into such lower portion which exhausts to the atmosphere. The air control diaphragm has a small air control passageway (of smaller diameter than the actuating passageway) allowing pressurized air into the air control cavity upper portion, thus permitting the pressurized air to act on both sides of the air control diaphragm.