The invention discloses a downstream under-pressure automatic closing
pressure regulator, which mainly consists of a main valve, a main regulation diaphragm box, a pressure regulation director ZH and a
back pressure controller HK, wherein the main regulation diaphragm box is assembled on the main valve, and the
back pressure controller HK is arranged at the air inlet end of the pressure regulation director ZH. The downstream pipeline pressure is guided into the
back pressure controller HK to act on a back pressure diaphragm, and pressure regulation air source signals input into the pressure regulation director can be controlled. When the downstream pressure is higher than the set under-pressure value, the pressure regulation director can obtain a
signal air source to carry out pressure regulation operation on the main valve, when the downstream pressure is lower than the set under-pressure value, the back
pressure controller can be automatically closed, and the
signal air source is
cut off, so that the
pressure regulator loses the control pressure, the main valve is closed, and the potential safety hazards during the maintenance operation on the downstream pipeline repair operation are thoroughly eliminated, and the gas use safety of downstream users is ensured. The downstream under-pressure automatic closing
pressure regulator has the obvious advantages that the structure is simple, the production cost is low, the installation and the use are convenient, the operation is stable, the work life is long, and the safety performance is high. The downstream under-pressure automatic closing pressure
regulator has very good application prospects in gas conveying industry.