Patent ID: 6854713

Claim:
A diaphragm valve for controlling inflow and outflow of fluid, comprising: a valve body with a chamber inside, a first flow channel and a second flow channel for connecting the chamber with the outside; a non-metal valve base, of ring type and installed in the first flow channel near the chamber, and being a little higher than an internal surface of the valve body; a fixed shrunk ring, installed in the non-metal valve base to fix the non-metal valve base to the first flow channel; a metal dish-type diaphragm set, which is installed in the chamber of the valve body above the first flow channel, and which cooperates with the non-metal valve base to block fluid between the first flow channel and the chamber, the metal dish-type diaphragm set including at least three diaphragms with an in-between diaphragm being a ring type and whose intension is less than that of the diaphragms on both sides thereof; and a stem, installed in the valve body near a side of the metal dish-type diaphragm set, and driving the metal dish-type diaphragm set to engage the non-metal valve base in order to block the circulation of fluid between the first flow channel and the chamber, and to release the metal dish-type diaphragm set to allow the fluid to enter the second flow channel via the first flow channel and the chamber.