A construction method for laying pressure steel pipes in a water tunnel of a hydropower station

Abstract

The present invention discloses a construction method for laying pressure penstocks inside a water tunnel of a hydropower station. Manufactured pressure penstocks are first transported to an installation site inside the water tunnel, antiseptic treatment is carried out on the pressure penstocks at the installation site and comprises a rust removing process and a spraying process, a shot peening method is used for the dust removing process, the grain size of the shots is 0.5-1.5 mm, the surface clearness of the pressure penstocks after rust removal reaches a Sa2.5 grade and above while the surface roughness reaches Ry40-70[mu]m, the spraying process is carried out after the dust removing process and comprises undercoat spraying and finish paint spraying, a solvent-free super-strength wear-resisting epoxy corrosion-prevention undercoat is adopted with the coating thickness being no smaller than 500 [mu]m, a solvent-free super-strength wear-resisting epoxy corrosion-prevention finish paint is adopted with the coating thickness being no smaller than 300 [mu]m, the spraying process is implemented at an environment temperature about 20 DEG C, and a spraying interval of the undercoat and the finish paint is 24 hours. The corrosion prevention quality of the pressure penstocks is ensured, the construction cost can be effectively lowered, and the construction duration is shortened.

Description

technical field [0001] The invention relates to a construction method for laying penstock steel pipes in water tunnels of hydropower stations, and belongs to the technical field of construction of buried penstock steel pipes in hydropower station tunnels. Background technique [0002] In water conservancy, hydropower and petroleum engineering, in order to improve the service life of the penstock, reduce the number of maintenance of the inner wall of the penstock, and ensure the long-term safe operation of the penstock, it is generally necessary to carry out anti-corrosion on the inner and outer walls of the penstock. At the same time, due to the high flow rate of the liquid in the steel pipe , will cause corrosion and wear to the anti-corrosion material in the pipe wall, and the maintenance after corrosion is difficult and expensive. Therefore, the anti-corrosion measures for pressure steel pipes should be carefully selected. [0003] Currently commonly used anti-corrosion ...

AI Technical Summary

Problems solved by technology

[0011] The object of the present invention is to provide a construction method for laying pressure steel pipes in the water tunnel of a hydropower station, so as to solve the problems of long construction period, high cost and difficult construction in the existing anti-corrosion measures and construction methods, so as to overcome the problems of the prior art insufficient