PRESSURE-TANK WATER-LEVEL CONTROL METHOD IN A PIPING SYSTEM USING A LEVEL TRANSMITTER AND A LEVEL SWITCH

摘要

The present invention relates to a water-level control method for a pressure tank, and relates to a method for accurately and reliably controlling the water level in a pressure tank by detecting level-transmitter abnormalities. The present invention is a pressure-tank water-level control method in a piping system having: a pressure tank; a level transmitter; a first level switch provided on a low-water-level warning line of the pressure tank; a second level switch provided between the low-water-level warning line and an appropriate-water-level-range lower limit line; a third level switch provided between a high-water-level warning line and an appropriate-water-level-range upper limit line of the pressure tank; a fourth level switch provided on the high-water-level warning line; and a gas-supply device for supplying a gas to the pressure tank, wherein the pressure-tank water-level control method comprises the steps of: receiving a pressure-tank water-level measurement value from the level transmitter; verifying by receiving on/off signals from each of the level switches; comparing the water-level measurement value of the level transmitter with the on/off signals of the level switches and thereby determining whether there is a level transmitter abnormality, and determining whether the water level in the pressure tank is actually rising or falling; and charging the pressure tank with the gas, or discharging the same therefrom, based on the result of the determination as to whether the water level in the pressure tank is rising or falling and on the on/off signals of the level switches.