The 1151 flange three-valve group is suitable for matching the 1151 series capacitive differential pressure transmitter products of the American company Siemont, and its function is to introduce the signal into the positive and negative measurement chamber of the 1151 series differential pressure transmitter from the impulse point, so that the impulse point and the measuring chamber are connected or disconnected, which is an indispensable accessory for the 1151 capacitive transmitter.