Abstract: A trunnion-type ball valve, a valve seal structure, and a valve packing in which, a seal surface pressure of a tip outer peripheral region is improved. A ball (3) provided inside a body (2) is rotatably provided via upper and lower stems (4 and 5) and is sealed with a ball seat (6). The trunnion-type ball valve has a packing attached between an outer periphery step part provided at a rear part of the ball seat and the body and a pressing mechanism by which the packing is pressed to a ball direction, and is provided with a contact surface to be contacted with a step part surface of the outer periphery step part on a tip outer diameter side of the packing and a space provided between the packing and the step part surface of the outer periphery step part on a tip inner diameter side of the packing.

Abstract: To contribute to an improvement in a dezincification resistance of a copper alloy, focusing attention on a relation between a dezincification resistance of a copper alloy and the crystal grain size of an ? phase, and the specific object is to provide a method of producing a hot forged product using a lead-free brass capable of ensuring corrosion resistances such as a prescribed dezincification resistance and the like even at sites of different thickness and shape, a hot forged product, and a wetted product such as a valve and a water faucet, molded using the same. A method of producing a hot forged product using a brass, comprising heat-treating a raw material to be subjected to forging work using a brass having a composition containing at least 59.2 to 63.0% by mass of Cu, 1.00 to 2.00% by mass of Sn and 0.05 to 0.25% by mass of Pb and containing the residue composed of Zn and inevitable impurities at a heating rate of 5.2° C./s or more from 350° C. until reaching the forging temperature.

Abstract: A butterfly-valve seat ring and fixing structure of the same, and an eccentric-type butterfly valve in which, the butterfly-valve seat ring has a flexible part (31) with a predetermined material thickness integrally and extendedly provided on one side surface of an inner diameter of a ring-shaped base body part (30) having a substantially rectangular shape in section and has a fixing part (32) integrally and extendedly provided on one side surface of an outer diameter of the base body part, has a recessed-shaped space part (40) provided between an outer circumferential surface (36) of the flexible part and an inner circumferential surface (37) of the fixing part, and has a seal contact part (35) provided to project at an inner diameter position of the flexible part. The seal contact part is positioned on an inner circumferential surface of the flexible part rather than a depth-side position of the space part.

Abstract: A structure and method for fastening a ball seat for a ball valve, a trunnion ball valve, and a hydrogen station using the ball valve, in which a stepped part is positioned medially in each of inner and outer peripheral surfaces of a resin-made annular seat body, with a seat part on a tip side and a holding part on a rear end side; an attachment groove defined by inner and outer cylinders having a ring-shaped swaging edge part at a tip of a seat retainer; the holding part being attached to the attachment groove; and the swaging edge part of the inner and outer cylinders being in contact with and fixed by being swaged to the stepped part so as to cause the seat part to protrude farther than a swaging position.

Abstract: Provided are a pressure-resistance inspection apparatus for valves and its inspection method, and hydrogen gas detection unit capable of detecting external leakage and specifying its position of occurrence even for valves with different sizes and shapes by performing pressure-resistance inspection with a simple structure quickly with high accuracy while preventing errors in test results, without requiring post-treatment for the valves, and also capable of mass processing by automation. Provided are a cover 2 in which a test valve 1 is accommodated in a state of being isolated from outside and a sensor 22 inside this cover 2 and capable of moving to a position close to an outer surface of the test valve 1 filled with a search gas. This sensor 22 is a gas sensor capable of detecting external leakage of the search gas from the test valve 1.

Abstract: Provided are a closed rearing method and a closed rearing apparatus which can decompose and remove ammonia contained in rearing water without supplying an excessive amount of ozone and can also suppress generation of toxic oxidants.

Abstract: By enhancing a stress corrosion cracking resistance in a leadless brass alloy, specifically by suppressing a velocity of propagation of corrosion cracks in the brass alloy, a straight line crack peculiar to the leadless brass alloy is suppressed, a probability of cracks coming into contact with ? phases is heightened and local corrosion on the brass surface is prevented to suppress induction of cracks by the local corrosion, thereby providing a leadless brass alloy contributable to enhancement of the stress corrosion cracking resistance. The present invention is directed to an Sn-containing Bi-based, Sn-containing Bi+Sb-based or Sn-containing Bi+Se+Sb-based leadless brass alloy excellent in stress corrosion cracking resistance, having an ?+? structure or ?+?+? structure and having ? phases distributed uniformly therein at a predetermined proportion to suppress local corrosion and induction of stress corrosion cracks.

Abstract: A trunnion-type ball valve including a seat retainer (14) attaching a ball seat(s) to at least one side of a ball (12) having a through hole (12a) provided in a body (11). The ball is turnably provided via a stem (13), and the ball seat is attached in a protrusion-prevented and free state in an attachment groove formed in the seat retainer. An excessive pressure due to an abnormal pressure rise in a cavity upon full close or upon full open is configured to be relieved into a flow channel via a communication part provided between an inner peripheral surface of the ball seat and the attachment groove by moving the seat retainer in a direction opposite to the ball by self-tension utilizing the pressure and pushing-out the ball seat to a ball-side by the excessive pressure flowed into a rear-surface side of the ball seat in the attachment groove.

Abstract: Provided is a brass alloy excellent in recyclability and corrosion resistance while avoiding the addition of Bi and Si, and with which machinability is ensured and processing is facilitated with preventing inclusion of lead. The present invention includes at least 58.0 to 63.0 mass % of Cu, 1.0 to 2.0 mass % of Sn and 0.05 to 0.29 mass % of Sb and the remainder composed of Zn and unavoidable impurities. With the present invention, stress corrosion crack resistance and machinability are improved. 0.05 to 1.5 mass % of Ni is included in a copper alloy to improve stress corrosion crack resistance as a result of the interaction between Ni and Sb. Furthermore, 0.05 to 0.2 mass % of P is included to improve anti-dezincification properties.

Abstract: Provided is a method for preventing the elution of Bi from copper alloy, in which the elution of Bi is prevented in leadless copper-alloy plumbing equipment and the like containing a trace of lead and a predetermined amount of Bi. The present invention relates to a method for preventing the elution of Bi from copper alloy in which at least Bi present on the surface of copper alloy containing Bi is selectively removed by preferentially dissolving Bi in a 4 to 20 mass % concentration of nitric acid while suppressing Cu dissolution. Furthermore, elution of Pb is suppressed using a 10-20 mass % concentration of nitric acid. In this case, by removing at least Bi present on the surface of copper alloy containing Bi using nitric acid and then treating the surface of the copper alloy by shot-blasting corrosive products, such as oxides, produced from the nitric acid are removed, and gloss is imparted to the surface.

Abstract: A high-pressure trunnion ball valve which is particularly suitable for a high-pressure fluid, the high-pressure trunnion ball valve is composed of a ball (10) rotatably provided in a body (3) having a lid member (2), a seat retainer (11) seal-connected to the ball, a spring member (12) applying an elastic force to the seat retainer to a seal side, and a seal member (13) attached to an outer circumferential face of the seat retainer. An upper stem (50) and a lower stem (51) having the same diameter are provided on an upper side and a lower side of the ball in an extending manner, respectively, to constitute a ball member (52), shaft-attaching seal mechanisms (20) having the same structure are attached to the upper and lower stems at symmetrical positions regarding the ball to achieve a balance structure, thereby avoiding thrust loads.

Abstract: A rotary valve and a quick exhaust valve for a railway vehicle in which high sealability and operability at the time of valve opening and closing are ensured. Outflow/inflow ports (10, 11) and a discharge port (12) are formed in a valve body accommodating part having a spherical surface part or a tapered surface part formed on part of an inner periphery in a body (2), and a valve body (3) is rotatably inserted from an opening which is open from the valve body accommodating part. A spherically-shaped surface part or a tapered-shaped surface part is formed at a position opposing the spherical surface part or the tapered surface part, a plurality of through ports communicating the outflow/inflow ports or the discharge port and an attachment groove opposing the outflow/inflow ports in a direction crossing the through ports are formed, and a seal member is attached to the attachment groove.

Abstract: A circulation type aquaculture method and a circulation type aquaculture apparatus which treat and remove ammonia harmful to fishes/shellfishes. The method includes a first step of finding an ammonia decomposition rate upon preliminarily treating cultivation water by using ozone or hypochloric acid so as to set a target remaining amount of ammonia after the decomposing treatment, a second step of finding the amount of ammonia in cultivation water so as to calculate a treating period of time required for reducing the amount of ammonia to the target remaining amount of ammonia based upon the ammonia decomposition rate of the first step, a third step of treating the cultivation water using ozone or hypochloric acid during the treating period of time calculated in the second step so as to treat and decompose ammonia in the cultivation water and a fourth step of returning the cultivation water to the aquaculture tank.

Abstract: To contribute to an improvement in a dezincification resistance of a copper alloy, focusing attention on a relation between a dezincification resistance of a copper alloy and the crystal grain size of an ? phase, and the specific object is to provide a method of producing a hot forged product using a lead-free brass capable of ensuring corrosion resistances such as a prescribed dezincification resistance and the like even at sites of different thickness and shape, a hot forged product, and a wetted product such as a valve and a water faucet, molded using the same. A method of producing a hot forged product using a brass, comprising heat-treating a raw material to be subjected to forging work using a brass having a composition containing at least 59.2 to 63.0% by mass of Cu, 1.00 to 2.00% by mass of Sn and 0.05 to 0.25% by mass of Pb and containing the residue composed of Zn and inevitable impurities at a heating rate of 5.2° C./s or more from 350° C. until reaching the forging temperature.

Abstract: A trunnion ball valve includes a ball provided inside a body main unit in a freely rotatable manner; and a seal mechanism provided on positions on both sides of the ball so as to be in seal contact with the ball, the seal mechanism including: a seat retainer having a sealing surface that is to be in seal contact with a ball surface of the ball; a spring member provided for applying elastic force on a sealing surface side; and a sealing member provided on an outer surface of the seat retainer.

Abstract: A trunnion ball valve for high pressure and a hydrogen station are provided, which achieves low torque during operation, and whose durability is improved to maintain sealing ability for a long period of time. In a trunnion ball valve including a ball provided inside a body main unit in a freely rotatable manner; and a seal mechanism provided on positions on both sides of the ball so as to be in seal contact with the ball, the seal mechanism including: a seat retainer having a sealing surface that is to be in seal contact with a ball surface of the ball; a spring member provided for applying elastic force on the sealing surface side; and a sealing member provided on an outer surface of the seat retainer, at least both of the sealing surface and the ball surface has a coating layer of diamond-like carbon provided thereon, so as to exhibit sliding ability and sealing performance.

Abstract: A shaft sealing device switches a sealing state and an unsealing state of a fluid, with high sealing performance maintained, because no abrasion accompanies movement of a sealing material or a sealing member, enabling feeding a fluid at a predetermined flow rate, and adjusts the expanding rate of the sealing material with the quantity of an external electric signal and accordingly adjusts the contact face pressure to enable controlling the amount of leakage of the fluid highly precisely, so that it can be used for all applications. The shaft sealing device includes a shaft sealing body formed of a macromolecular material and made expansible or contractible, or deformable, through external electrostimuli applied to a shaft sealing portion disposed in a device body, and flow passages disposed in the shaft sealing portion for feeding the fluid leaked due to the expansion or contraction, or the deformation, of the shaft sealing body.