At 11:45 p.m. local time on August 28, the first unit of the Tarbela 5 Hydropower Extension Project in Pakistan, undertaken by Harbin Electric International (HEI), successfully completed its spiral case hydrostatic test. The milestone marks a major breakthrough in the installation of the unit and lays a solid foundation for subsequent hydrogenerator pit concrete placement, installation of the unit’s main equipment, and eventual commercial power generation.

The spiral case is a critical pressure-bearing component of a hydroelectric generating unit. Its manufacturing precision, weld sealing performance, and overall structural stability directly affect the unit’s safety and stability after commissioning, making it a key focus of quality control during the unit installation process. The spiral case hydrostatic test lasted approximately five hours. In strict accordance with industry standards, the test was carried out through the complete sequence of gradual pressurization, pressure holding, and depressurization. The maximum test pressure reached 2.37 MPa, equivalent to the pressure exerted by a 230-meter column of water, and the pressure was stably maintained at the specified high-pressure level for 30 minutes. All process parameters met the required standards.

To ensure the successful completion of the test, the project team prioritized planning and maintained strict control over details, carrying out all preparatory work to a high standard. Personnel were organized to check and verify the pressurization equipment, monitoring instruments, sealing devices, and safety protection facilities one by one. During the test, the project team strictly followed standardized operating procedures, steadily increasing the pressure, accurately maintaining the required pressure, and systematically reducing the pressure in accordance with the predetermined pressure curve. Key process parameters, including the pressurization rate and pressure-holding duration, were strictly controlled throughout the test. At the same time, monitoring data such as pressure and structural deformation were collected, while comprehensive leakage inspections were conducted on all welds, sealing interfaces, and connection points of the spiral case. The successful completion of the test fully verified the excellent manufacturing workmanship of the unit’s spiral case and the high-precision quality of its installation.

Going forward, the Tarbela 5 Hydropower Extension Project team will continue to uphold the bottom line of safety and quality, optimize construction plans, precisely control construction milestones, and steadily advance the subsequent electromechanical installation work. Every effort will be made to ensure the high-quality and efficient construction of the project, contribute to the development and utilization of clean energy in Pakistan, and strive to achieve the target of generating power with the first unit in 2027, adding another landmark achievement to China-Pakistan energy cooperation.