Abstract: A repair welding method according to at least one embodiment is for a member in which a first end and a second end of a parent material are connected by welding and includes: a step of removing a portion including at least a part of a first heat-affected zone of an existing welded portion of the member; and a step of performing repair welding after removing the portion. In a cross-section including the parent material and the existing welded portion, all intersection portions between the first heat-affected zone of the existing welded portion and a second heat-affected zone due to the repair welding have an intersection angle between the first heat-affected zone and the second heat-affected zone of 70° to 110°.

Abstract: A repair welding method according to at least one embodiment is for a member in which a first end and a second end of a parent material are connected by welding and includes: a step of removing a portion including at least a part of a first heat-affected zone of an existing welded portion of the member; and a step of performing repair welding after removing the portion. In a cross-section including the parent material and the existing welded portion, all intersection portions between the first heat-affected zone of the existing welded portion and a second heat-affected zone due to the repair welding have an intersection angle between the first heat-affected zone and the second heat-affected zone of 70° to 110°.

Abstract: A pump with high performance and cleanability includes a casing having a smaller volute and a larger volute; a space between an outer circumference of an impeller and a starting end of the smaller volute being greater than that of the larger volute, generating a circulating flow of self-priming water from the smaller volute to the larger volute; and a diffusing part of the larger volute being formed into an upright, cylindrical self-priming water separating chamber guiding the self-priming water from the smaller volute to flow in for air-water separation. An inner circumference part of the casing is formed concentric with the outer circumference of the impeller with a predetermined space therebetween; defining members are protrusively disposed on the inner circumference part of the casing so as to define the shapes of the two volutes; and the self-priming water separating chamber is made attachable to and detachable from the casing.

Abstract: This invention provides a microscopic bubble generator that can stably/efficiently generate a large amount of microscopic bubbles in liquid in a short time and can be easily cleaned in an assembled state and in a disassembled state, and a gas-liquid dissolving tank that can be suitably used for the apparatus. In the gas-liquid dissolving tank that promotes dissolution of gas mixed with liquid in the liquid, openings that pass the flowing gas-liquid are formed at an upper portion and a lower portion of a container of the tank, a plurality of separation walls that vertically divide a plurality of chambers are disposed in the container, openings that connect upper and lower chambers are formed through the separation walls, the upper ends of the openings of the separation walls extend predetermined distances upward from the separation walls, and the lower ends of the openings of the separation walls extend predetermined distances downward from the separation walls.

Abstract: This invention provides a microscopic bubble generator that can stably/efficiently generate a large amount of microscopic bubbles in liquid in a short time and can be easily cleaned in an assembled state and in a disassembled state, and a gas-liquid dissolving tank that can be suitably used for the apparatus. In the gas-liquid dissolving tank that promotes dissolution of gas mixed with liquid in the liquid, openings that pass the flowing gas-liquid are formed at an upper portion and a lower portion of a container of the tank, a plurality of separation walls that vertically divide a plurality of chambers are disposed in the container, openings that connect upper and lower chambers are formed through the separation walls, the upper ends of the openings of the separation walls extend predetermined distances upward from the separation walls, and the lower ends of the openings of the separation walls extend predetermined distances downward from the separation walls.

Abstract: A pump with high performance and cleanability includes a casing having a smaller volute and a larger volute; a space between an outer circumference of an impeller and a starting end of the smaller volute being greater than that of the larger volute, generating a circulating flow of self-priming water from the smaller volute to the larger volute; and a diffusing part of the larger volute being formed into an upright, cylindrical self-priming water separating chamber guiding the self-priming water from the smaller volute to flow in for air-water separation. An inner circumference part of the casing is formed concentric with the outer circumference of the impeller with a predetermined space therebetween; defining members are protrusively disposed on the inner circumference part of the casing so as to define the shapes of the two volutes; and the self-priming water separating chamber is made attachable to and detachable from the casing.

Abstract: In order to provide a welding structure of a tube header and tube stubs which successfully improves the durability thereof against creep and fatigue damage of the tube stubs without interposing a component of a different material between the tube header and the tube stubs, i.e. requiring additional components, a welding structure of the present invention comprises: a tube header (2) being made of ferritic heat resisting steel; a plurality of tube stubs (4) which are welded onto an outer surface of the tube header, each of the tube stubs having a bended section, in which the plurality of tube stubs (4) are made of austenite stainless steel, and welded to the tube header (2) by using nickel base alloy as a welding material.

Abstract: The present invention provides a gas-liquid separator with enhanced performance and easy operation, enabling to perform gas-liquid separation such as advanced defoaming or degassing, and facilitating easy cleaning with CIP (Cleaning In Place) and COP (Cleaning Out Place) ability that meets sanitary specifications. This gas-liquid separator for gas-liquid separation performed by centrifugal force of an impeller mounted on a shaft which rotates in a casing comprises: a discharge impeller part providing discharge force to the passing fluid formed on an axial end of the impeller; a discharge outlet of the casing disposed in a position opposite the discharge impeller part; the other axial end of the impeller being formed to slide on the inner wall of the casing; an exhaust outlet of the casing disposed in a position opposite the sliding impeller part; vacuum means connected to the exhaust outlet; and a suction inlet of the casing disposed in a position between the discharge outlet and the exhaust outlet.

Abstract: The present invention provides a gas-liquid separator with enhanced performance and easy operation, enabling to perform gas-liquid separation such as advanced defoaming or degassing, and facilitating easy cleaning with CIP (Cleaning In Place) and COP (Cleaning Out Place) ability that meets sanitary specifications. This gas-liquid separator for gas-liquid separation performed by centrifugal force of an impeller mounted on a shaft which rotates in a casing comprises: a discharge impeller part providing discharge force to the passing fluid formed on an axial end of the impeller; a discharge outlet of the casing disposed in a position opposite the discharge impeller part; the other axial end of the impeller being formed to slide on the inner wall of the casing; an exhaust outlet of the casing disposed in a position opposite the sliding impeller part; vacuum means connected to the exhaust outlet; and a suction inlet of the casing disposed in a position between the discharge outlet and the exhaust outlet.

Abstract: A welding method and a welded joint for high strength, temperature resistant steels produce the same strength as the base metal in the welded joint, thereby resolving strength problems in the heat affected area by making a simple change to the welding method. Additionally, this advantage is extended to high strength ferrite heat resistant steels by providing a multi-pass buildup welding method for such high strength ferrite heat resistant steels. A multi-layered cap 15a fusion area extends past the heat affected area 13 that lies outside groove 11, and the surface area of the foregoing extension that is required to impart the same level of creep strength as is inherent in the base metal is based on the relationship between the groove width and the base metal thickness shown as hatched area in FIG. 1(B).

Abstract: This invention provides a welding method and a welded joint for high strength, temperature resistant steels that produces the same strength as the base metal in the welded joint, thereby resolving the strength problems in the heat affected area by making a simple change to the welding method, and additionally, to extend this advantage to high strength ferrite heat resistant steels by providing a multi-pass buildup welding method for such high strength ferrite heat resistant steels. The multi-layered cap 15a fusion area extends past the heat affected area 13 that lies outside groove 11, and the surface area of the foregoing extension that is required to impart the same level of creep strength as is inherent in the base metal is based on the relationship between the groove width and the base metal thickness shown as hatched area in FIG. 1(B).