106 / 206-A-Type 1 is a two-way flow altitude control valve. It is ideal in keeping a preset maximum water level. The valve can either be a fully open or closed valve. Type 1 allows the usual flow to fill the reservoir to the maximum level and then it closes at the set-point. The valve opens to permit the reverse of flow through the valve when the supply pressure drops. The cycle continues when a higher supply pressure is restored the valve will allow normal flow that will refill the tank to the maximum level. No overflows and it has superior repeatability. It is easily serviceable at ground level.