Abstract: To provide a diaphragm and a diaphragm valve which solve a problem of deterioration of air-tightness due to insufficient tightening of a bolt and damage to the diaphragm due to over-tightening of the bolt, as well as reducing variations in performance such as durability of the diaphragm and simplifying tightening work. A diaphragm is provided with a through hole having a diameter larger than a diameter through which a bolt can be fitly inserted. A bolt insertion cylinder made of metal through which the bolt can be inserted is fitted in the through hole. A height of the bolt insertion cylinder is equal to or less than a height of the through hole.

Abstract: Provided is a small-sized controller capable of precisely controlling a flow rate of a high-pressure fluid. Between a working shaft of a drive device and a valve stem, a power transmission device is disposed to amplify a force acting on the working shaft and transmit the resultant force to the valve stem. A diaphragm as a valve element is made of metal and is deformable to: a state where a fluid passage is fully closed; a state where the fluid passage is fully open; or a state where the fluid passage is partially open. When the fluid passage is partially open, on the basis of the flow rate of a fluid flowing through fluid passages, the drive device finely adjusts the position of the working shaft such that the flow rate is constant.

Abstract: The diaphragm valve comprises a body with a flow path, a stem, a diaphragm, a diaphragm depressor attached to the lower end of the stem, and a connecting member which connects the diaphragm and the diaphragm depressor. Further, the connecting member has a rod-shaped part to be connected to the diaphragm depressor and a flange part which is radially protruding in a circular shape at the lower end of the connecting member and having at least one notch on the outer peripheral edge. Furthermore, the rod-shaped part has a radially concaved constriction part above the flange part, and the flange part and the constriction part are embedded in the central part of the diaphragm.

Abstract: Provided is a small-sized controller capable of precisely controlling a flow rate of a high-pressure fluid. Between a working shaft of a drive device and a valve stem, a power transmission device is disposed to amplify a force acting on the working shaft and transmit the resultant force to the valve stem. A diaphragm as a valve element is made of metal and is deformable to: a state where a fluid passage is fully closed; a state where the fluid passage is fully open; or a state where the fluid passage is partially open. When the fluid passage is partially open, on the basis of the flow rate of a fluid flowing through fluid passages, the drive device finely adjusts the position of the working shaft such that the flow rate is constant.

Abstract: A durable diaphragm valve has a single-layer structure consisting of rubber materials. The single-layer structure has a membrane part deforming and moving up and down with opening and closing of a flow channel and a flange part which is provided around said membrane part and sandwiched between a valve body and a bonnet. The flange part has an annular ridge consisting of an upper ridge protruding upward and a lower ridge protruding downward from a position corresponding to said upper ridge. The upper ridge has an inner upper ridge and an outer upper ridge with its protruding height being lower than the inner upper ridge, which are consecutively formed in a staircase pattern.

Abstract: A durable diaphragm valve has a single-layer structure consisting of rubber materials. The single-layer structure has a membrane part deforming and moving up and down with opening and closing of a flow channel and a flange part which is provided around said membrane part and sandwiched between a valve body and a bonnet. The flange part has an annular ridge consisting of an upper ridge protruding upward and a lower ridge protruding downward from a position corresponding to said upper ridge. The upper ridge has an inner upper ridge and an outer upper ridge with its protruding height being lower than the inner upper ridge, which are consecutively formed in a staircase pattern.

Abstract: A diaphragm with excellent durability is provided which can restrain occurrence of a crack resulting from up and down movements of the diaphragm with opening and closing of a flow channel of a diaphragm valve, and a diaphragm valve having this diaphragm. The diaphragm is attached to a diaphragm valve, comprising a membrane part deforming and moving up and down with opening and closing of a flow channel and a flange part which is provided around said membrane part and sandwiched between a valve body and a bonnet, wherein the diaphragm is formed in a curved surface shape where the shape before deformation of the lower surface of said membrane part descends and then ascends from an outer edge part towards a central part.