The invention relates to the technical field of pressure valves, and provides a high-back-pressure
pneumatic valve for a
semiconductor chemical
system and an assembling method of the high-back-pressure
pneumatic valve. The high-back-pressure
pneumatic valve comprises an air cylinder
assembly, a diaphragm and a
valve seat. The cylinder
assembly is provided with a cylinder upper cover and a cylinder body which are connected through a rotary lock catch structure, and the
piston is assembled on the cylinder body. The diaphragm is provided with a sealing
diaphragm part and a valve element integrally arranged in the center, the sealing
diaphragm part is provided with a pressure-bearing protrusion and a sealing hook, and the pressure-bearing protrusion provides a
back pressure counteracting area accounting for 25%-50% of the flexible area of the diaphragm. A
valve port and a flow channel are formed in the
valve seat, a mounting hole aligned with the
valve port is formed in the
valve seat, a sealing clamping groove is formed in the mounting hole, and the sealing clamping groove and the sealing hook are matched to form a sealing interface. The valve element table body is arranged at the
valve port and driven by the air cylinder
assembly to seal or break away from the valve port. According to the invention, high-back-pressure fluid
impact can be effectively balanced, and the assembly efficiency and the maintenance convenience are greatly improved.