| abstract |
An adjustment valve includes a first diaphragm integrally formed from an attachment section engaged with and fixed to the bottom of a rod, a joining section to which a valve body is fixed, a thin film section radially extending from a shoulder section, a thick wall section continuous with the thin film section, and a seal section provided at the peripheral edge of the thick wall section. The second diaphragm has a central hole, and includes an integrally formed thin film section radially extending from a thick wall section at the center hole, and a seal section is provided at the peripheral edge thereof. A diaphragm hold-down member penetrates the central hole at the shoulder section of the rod, causing the second diaphragm to be sandwiched and fixed. The rod is disposed with play in the through-hole in the bottom of the cylinder, and is supported by a spring engaged between a step section of the cylinder and the bottom surface of the shoulder in a state such that radial movement is prevented. |