Mechanical equipment and its assembly at the Krasnoyarsk hydroelectric station

Conclusions

• 1. Steels 09G2, 09G2S, and 138IZ delivered as sheets in a standardized and improved state with a guaranteed impact strength norm at temperatures from \t-40\dg to \t-70\dgC are among the most reliable steels, other conditions being equal, and therefore are recommended for the manufacture of mechanical equipment and metal structural members of hydraulic structures constructed in regions where the air temperature is below \t-40\dgC.

• 2. The deep gates, intended for operation during the construction period, should be designed on the basis of the norms for the designing of service gates, their manufacture should be accomplished within the allowance accepted in machine construction, and careful work is required during their assembly.

• 3. The quality of the assembly and welding of the aeration tubes should be high, and all welds should be strong and tight to prevent entrance of cement mortar during injection. Before concreting the aeration tubes, the tightness and strength of the welds should be checked hydraulically. li]4.|A high efficiency when constructing the penstocks can be achieved only by reducing the entire assembly cycle: a) by introducing effective welding methods; b) by using highly productive specialized and universal assemblywelding machines. The well-developed technology of enlarging and assembling penstocks, the construction of a yard for consolidating the links of the pipe line and other structural members and equipment, the creation of a shop for assembling and automatic welding andx-ray inspection, the development of special devices and properly selected equipment of the welding shop (stands for welding straight links and elbows, flux cushions, bridge crane, etc.) have made it possible to industrialize and shorten the period of installation of the pipe lines and to improve considerably the quality of the work.

• 4. The use of 50-ton tower cranes along the route has greatly facilitated the assembly of the links of the pipe lines and reduced the time of their assembly.

• 5. The rather simple and fast method of raising the tower cranes from one level to another, which was mastered by \ldGidromontazh\rd Trust, made it possible to perform concreting on the dam successfully.

• 6. Of particular value is the use of concreted seats at the final state of construction under conditions of a flooded pit and successive startup of the turbine-generator units, when the front of the works and the area of the construction site are being reduced markedly. Industrialization of all work at this stage largely compensates for reduction in the construction rate which is inevitably caused by los, of communications and production areas.