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.

Abstract: A method is provided for preventing copper and zinc from being eluted from a copper-alloy-made plumbing instrument that includes valves and pipe joints and suppresses copper and zinc from being eluted from the copper-alloy-made plumbing instrument while using for the plumbing instrument copper alloy as-is that includes bronze and brass, to provide a copper-alloy-made plumbing instrument using the method and to provide a film-forming agent. The method forms on at least a liquid-contact portion of the copper-alloy-made plumbing instrument a film of an organic substance comprising unsaturated fatty acid and coating with the film both copper and zinc in the surface layer of the liquid-contact portion of the plumbing instrument, thereby suppressing the elution of copper and zinc.

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.

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: 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 polymer actuator is capable of being utilized for any of various drive sources, and the amount of deformation of the polymer actuator can particularly be used also for a valve or shaft-sealing device. The polymer actuator includes a power driver deformed upon receiving electro stimuli and electrodes disposed on the upper and lower surface sides of the power driver in an opposite manner for applying positive and negative electro stimuli to the power driver in a planar fashion. The electrodes have different stimuli application regions to have different electrical field distributions for causing distribution of stress generated in the power driver to be eccentrically located on one of positive and negative sides, thereby bending and deforming the power driver onto a side on which the opposite stimuli application regions do not exist.

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 fluid purification device includes an inner tube composed of a non-conductive material and an outer tube which is spaced apart from the inner tube by predetermined space S and composed of a non-conductive material, and the tubes are concentrically arranged. A conductive member is attached to apart or entire periphery of the inside of the outer tube to provide an electrode so as to form a device main body. When a voltage is applied to the electrode of the device main body, discharge in the space S is created by using a fluid to be treated W composed of liquid such as water which flows within the inner tube as an earth electrode. This causes a gas such as oxygen or air flowing in the space S to be reacted to generate ozone and mixes the ozone with the fluid to be treated W so as to purify the fluid.