What valves do Brazilian hydropower stations use?

The valve selection of hydropower station is a systematic project, which needs to be judged according to the function positioning, medium characteristics, pressure level and installation space. The mainstream valve types are concentrated in the butterfly valve, gate valve, ball valve, check valve, globe valve five categories.

Why do hydropower plants need so many different types of valves?

The core of a hydropower station is the conversion of water flow energy, but a huge auxiliary system runs around the generator set. Functionally, these systems can be grouped into three broad categories:

Water supply: technical water supply, fire water supply, domestic water supply

Drainage: leakage drainage, maintenance drainage, factory drainage

Auxiliary medium: oil system, compressed air system

Each system has different medium, pressure, and caliber requirements, which determine the difference in valve type.

Technical logic of valve selection for each system

The technical water supply system is the lifeblood of the cooling of the generator set, with large pipe diameter (DN50-DN400) and medium pressure (1.0-2.5MPa). Butterfly valve here has a natural advantage - short structure length, light weight, 90°fast opening and closing, suitable for large diameter pipeline; Gate valve as an isolation valve, the flow resistance is close to zero when fully open, does not increase system energy consumption; Check valve is installed at the pump outlet to prevent water hammer impact during shutdown. It should be noted that the water source of hydropower stations is mostly river water with high sediment content, and the sealing surface should have the ability of erosion resistance.

The pressure of drainage system (leakage, maintenance, factory area) is low (0.6-1.0MPa), but the reliability requirement is high. A gate + butterfly + check valve combination is standard.

The oil system (turbine oil, insulating oil) requires high cleanliness and tightness, and ball valve and globe valve are the mainstream choice. Ball valve full diameter design does not accumulate grease, globe valve is suitable for flow adjustment, diameter is generally small (DN15-DN80), but the pressure can reach 4.0MPa.

Finally, a practical selection of recommendations, hydropower station valve failure is often costly - downtime means loss of power generation. Therefore, when selecting models, do not only look at the initial cost, but also pay attention to the durability of the seal, the ability to resist sediment erosion and the maintenance cycle.