Abstract: An ultra high head pumpturbine power generating plant with a turbine having a runner rotating with water flow supplied through a high head conducting tube. A rotary electric machine rotates with rotation of the runner. The head is in the range of 400-600 m, and the runner is at least 5 meters in diameter. The said runner has characteristics of toughness at room temperature: at least 500 N/mm.sup.2, or tensile strength at room temperature: at least 650 N/mm.sup.2, elongation at least 16%, reduction of area at least 45%, 2 mm U-notch impact value at 0.degree. C. at least 100 J, and fracture toughness at least 6000 N/mm.sup.3/2.

Abstract: High toughness stainless steel type 13Cr5Ni containing C: 0.008-0.03% (by weight, all of the following elements), Si: max. 1%, Mn: max. 2%, Cr: 10.0-14.0%, Ni: 4.0-7.0%, and Mo: 0.2-2.0%, in which (Cr/Ni) ratio is in a range of 2.0-3.0 or (C/Mo) ratio is in a range of 0.015-0.1, as a structural material for fluid machinery, austenitic stainless steel containing C: 0.10-0.30% (by weight, all of the following elements), Si: max. 1%, Mn: max. 2%, Cr: 16.00-23.00%, Ni: 1.00-8.00%, and Co: 2.00-9.00%, and Ni+Co: 6.00-12.00% as a weld padding layer forming material, and fluid machinery using the same.

Abstract: A water turbine runner has a plurality of vanes, each made of a rolled steel plates which contains, by weight, 0.01 to 0.10% of C, 0.10 to 1.0% of Si, 0.10 to 2% of Mn, 2 to 7% of Ni, 10 to 15% of Cr and 0.10 to 4% of Mo, 71.9 to 87.7% of Fe, and which has a metallic structure mixture containing, by volume, martensite and 10 to 35% of residual austenite. Each of the vanes is made of a plurality of plate pieces, cut out from the rolled steel plate, press-formed in a shape of a part of the vane and joined by welding into the complete vane.

Abstract: In a wicket gate protecting device for hydraulic machines, a pair of link plates transmitting a force between a gate control ring and a gate lever, is connected to the gate lever through a shear pin. The gate lever disposed between the link plates, and rotatably supported about the shear pin. When the movement of the wicket gate is restricted by obstacles entered between adjacent gate vanes, the shear pin is cut and a part of the shear pin supporting the gate lever moves along between the link plates for a distance and is stopped by friction between the link plates and the shear pin, thereby preventing damage to the neighboring gate vanes.