Electric ball valves are widely used in municipal projects and industrial pipe networks, so how many meters should one be installed on the pipeline. The penstock is arranged in such a way that one main pipe is divided into three branches through two bifurcated pipes to supply water to three units in the powerhouse.
The upper flat section, inclined section and the first half of the lower flat section of the pipeline are buried in rock, and the second half of the lower flat section is buried in sand and gravel. The main pipe has a diameter of 4.20m and a length of 334.15m, of which the upper flat section is 26.70m long, the inclined pipe is 148.44m long, with an included angle of 53 ° to the horizontal, the lower flat section is 134.96m long, the inner diameter of the branch pipe is gradually changed from 2.42m to 2.00m, connected with the butterfly valve in the plant, * the short branch pipe is 22.85m long, * the long branch pipe is 34.50m long. Since the powerhouse is ground type and the foundation overburden of the powerhouse is deep, the lower flat section of the penstock needs to cross the boundary between bedrock and overburden. In order to adapt to the uneven settlement and temperature deformation of the overburden foundation, a main pipe is set at the boundary between bedrock and overburden where the main pipe crosses.
The foundation of the powerhouse is treated with vibroflotation gravel piles. The foundation bearing capacity of the penstock bifurcated pipe and branch pipe section can meet the requirements and will not be treated, but in consideration of the possible settlement difference between the branch pipe and the powerhouse, a branch pipe is set on the branch pipe of the upstream wall of the powerhouse. The electric pipe ball valve is composed of upstream and downstream connecting pipes, intermediate connecting pipes and two compensation pipes in series. The electric pipe ball valve has the advantages of compact structure, high pressure bearing capacity, good working performance, simple piping, corrosion resistance, easy maintenance, etc. Since the penstock is wrapped with concrete and backfilled with sand and gravel to the ground elevation of the plant area, a permanent deformation joint is set at both ends of the main pipe section, and a certain thickness is wrapped with flexible materials outside the section, and then the concrete is wrapped to ensure the free displacement of the electric ball valve of the pipe. The branch pipe joint is arranged under the auxiliary power house, and the design adopts the way of setting the manhole.