Abstract: A valve having a simple configuration that prevents the seat from being damaged by self-excited oscillation of the valve body and thus prevents seat leakage. The valve includes a valve casing having a fluid inlet, a fluid outlet, and a valve chamber; the valve chamber including a seat having a seat surface; a stem inserted into the valve casing so that the stem can be vertically movable; and a valve body arranged at a tip of the stem and capable of abutting on the seat surface of the seat due to the vertical movement of the stem such that a tip part of the valve body does not come into contact with the seat surface due to oscillation of the stem.

Abstract: A valve having a simple configuration that prevents the seat from being damaged by self-excited oscillation of the valve body and thus prevents seat leakage is disclosed. The valve includes a valve casing having a fluid inlet, a fluid outlet, and a valve chamber; the valve chamber including a seat having a seat surface; a stem inserted into the valve casing so that the stem can be vertically movable; and a valve body arranged at a tip of the stem and capable of abutting on the seat surface of the seat due to the vertical movement of the stem such that a tip part of the valve body does not come into contact with the seat surface due to oscillation of the stem.

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.

Abstract: A specified metal member (e.g., a bolt) 5 included among a plurality of components 2, 3, 4, 5, 6 of a fluid handling part and having a surface exposed on an exterior of the fluid handling part is made of an alloy comprising, in % by weight, 0.001 to 0.01% of C, up to 5% of Si, up to 2% of Mn, up to 0.03% of P, up to 100 ppm of S, up to 50 ppm of O, 18 to 25% of Cr, 15 to 25% of Ni, 4.5 to 7.0% of Mo, 0.5 to 3.0% of Cu, 0.1 to 0.3% of N, and the balance substantially Fe and other inevitable impurities.

Abstract: A control valve comprises a valve body having a fluid channel and a valve seat; a valve operating part; a valve stem supporting member having its upper end fixed to the valve operating part and its lower end fixed to the valve body; a valve stem penetrating the valve stem supporting member and having its upper end part connected to the valve operating part and its lower end part entering the valve body, the valve stem being movable upward or downward by the valve operating part; and a valve element attached to the lower end of the valve stem. The valve element is moved upward or downward by moving the valve stem upward or downward, the valve element being brought into contact with and seated in the valve seat to close a fluid channel as it is moved downward, the valve element being detached from the valve seat to open the fluid channel as it is moved upward.