Abstract: A floor surface blasting apparatus is used for removing rustproof coating (blasting) on a tank bottom surface to inspect weld lines on the bottom surface of high-capacity fuel tank. The floor surface blasting apparatus comprises a work arm which has weld line detecting sensors for detecting a weld line at the tip end and also has a blast head incorporating a suction nozzle; a work carriage which has the work arm and magnet devices incorporating a magnetic substance and travels arbitrarily on the floor surface; a transfer carriage which has a blast device for supplying blasting material to the blast head and travels arbitrarily on the floor surface; and a control device which controls the blast head so that the blast head is positioned on a weld line in accordance with the detection signal from the weld line detecting sensors and the signal of a position detecting device for detecting the position of the blast head and also makes the transfer carriage follow the work carriage.

Abstract: A floor surface blasting apparatus is used for removing rustproof coating (blasting ) on a tank bottom surface to inspect weld lines on the bottom surface of high-capacity fuel tank. The floor surface blasting apparatus comprises a work arm which has weld line detecting sensors for detecting a weld line at the tip end and also has a blast head incorporating a suction nozzle; a work carriage which has the work arm and magnet devices incorporating a magnetic substance and travels arbitrarily on the floor surface; a transfer carriage which has a blast device for supplying blasting material to the blast head and travels arbitrarily on the floor surface; and a control device which controls the blast head so that the blast head is positioned on a weld line in accordance with the detection signal from the weld line detecting sensors and the signal of a position detecting device for detecting the position of the blast head and also makes the transfer carriage follow the work carriage.

Abstract: A floor surface blasting apparatus is used for removing rustproof coating (blasting) on a tank bottom surface to inspect weld lines on the bottom surface of high-capacity fuel tank. The floor surface blasting apparatus comprises a work arm which has weld line detecting sensors for detecting a weld line at the tip end and also has a blast head incorporating a suction nozzle; a work carriage which has the work arm and magnet devices incorporating a magnetic substance and travels arbitrarily on the floor surface; a transfer carriage which has a blast device for supplying blasting material to the blast head and travels arbitrarily on the floor surface; and a control device which controls the blast head so that the blast head is positioned on a weld line in accordance with the detection signal from the weld line detecting sensors and the signal of a position detecting device for detecting the position of the blast head and also makes the transfer carriage follow the work carriage.

Abstract: A hydraulic blasting apparatus has an abrasive storage tank disposed operatively between an abrasive recovery tank and a hydraulic pressurized tank. The abrasive storage tank is provided with a first valve openable from the inside of the storage tank to the atmospheric pressure, and also with a second valve to open the connection between the storage tank and the recovery tank and with a third valve to open the connection between the storage tank and the pressurized tank. The pressure in the abrasive storage tank will become the same as the atmospheric pressure by opening the first valve. Next the first and second valve are closed, and after that the third valve is opened so as to drop the abrasive only into the pressurized abrasive tank for a recycle use.

Abstract: A powdery material supply valve mechanism including a valve means disposed in front of a piston rod means in a longitudinally aligned relationship with each other, a valve housing means incorporating operatively the valve means and the piston rod means therein and a valve cylinder/piston means. This valve cylinder means is disposed shiftably in the longitudinal direction relative to the valve housing means, and a valve piston means disposed slidably in the bore of the cylinder means along the axis thereof to be urged operatively upon a valve seat of the valve housing means against the resilient force of a valve spring means under the effect of operating fluid pressure fed to the valve cylinder means, while the valve means is opened away from its valve seat with the resilient force of the valve spring means, when the operating fluid pressure is opened to the atmosphere.

Abstract: A welding beveling of a T-joint of a member welded to a rib on a lower plate, the rib varying in thickness along its length, comprises a beveling on an upper plate partially overlapping the rib at the thicker portion of the rib and having a clearance between the upper plate and the rib at the thinner portion, and a part of the beveling at the thicker rib portion being provided with a detecting hole for detecting the overlap.

Abstract: A method for assembling narrow gap members by welding is described. In the method, separate narrow gap members having spaces therein when assembled are provided and a deformation-preventive material consisting of a water-soluble material or a material capable of being disintegrated with water is filled in each space and is formed with a through groove or hole in the filled preventive material. In this state, the separate narrow gap members are subjected to welding, and immersed in water to remove the deformation-preventive material from each space. The through grooves may have a width larger than a leg length of each penetration bead, in which a heat-resistant flux is filled in each groove. The deformation-preventive material may be covered with a heat-resistant ceramic backing member shaped in a specific form or with a heat-resistant particle layer and a copper member shaped in conformity with an intended size and shape of a penetration bead.

Abstract: A T-jointing weld beveling for welding a plate member to a rib-like member having a varying thickness in a T-shaped manner is improved in that a beveling width changes in accordance with the thickness of the rib-like member and the edges of the beveled portion are wave-shaped so as to form intermittent gap space portions between the rib-like member and said edges, whereby uniform penetration beads can be formed, the welding can be achieved with a small electric current over the entire length of the rib-like member, and control of a welding condition can be facilitated.