Exposed Piping Installation - Voith Snowy 2.0

⁠⁠⁠Installation and testing:

• Complete installation and testing of piping spools, pumps, vessels, structural steel platforms, piping supports preassembly, valves, inline equipment and instrumentation of the following water systems in accordance with the Employers Requirements, statutory and project requirements:

1.  Station Cooling Water System
2.  Unit Cooling Water System for Units 1 to 6.
3.  Drainage and Dewatering System
4.  Turbine Dewatering System for Units 1 to 6
5.  Oil Separator System

• Provide all consumable materials, tools and temporary equipment required to complete the installation of those listed in the above systems. Equipment and consumable material requirements include, but are not limited to, welding equipment and welding consumables, cleaning and special equipment and tools, drill plugs, anchors, drilling equipment, and trade-required tools for installation and testing

• Piping & spooled materials are all free-issued, except for the consumables listed above.

• All Practical Completion requirements.

Station Cooling Water System

The SCW is an open circuit configuration. The water of SCW system is extracted with three extraction lines from the draft tube gates of Unit 02, Unit 03 and Unit 05. Each of these tapping lines is sufficient to meet demand of the entire SCW system. After

passing the related filter and pump, the water is pumped to the consumers and returned to the downstream surge shaft.

The SCW system has three 100% operating capacity intake pipes, three 100% operating capacity pump/filter sets and two 100% operating capacity supply pipes, headers, and discharge lines. The pump/filter sets are installed in TH on the elevation 450masl. The fire pump supply is branched off two of the three intake pipes. One of the 3 extraction points is located on the downstream side of the draft tube gate of Unit 03. The other extraction points are located on the upstream side of the associated draft tube gate. This configuration ensures the fire pump supply, even when the DTG gates are closed.

Unit Cooling Water System

The UCW is an open circuit configuration for each pump-turbine unit. The water of each UCW system is extracted with one extraction line from the draft tube liner of the associated unit.

After passing the system related filter and pump, the water is pumped to the consumers and returned to the downstream surge shaft.

The UCW system consists of two redundant pump and filter sets, each with 100% operating capacity and a single discharge manifold. In each circuit one pump/filter set is active at a time, the other pump/filter set is switched off.

Drainage and Dewatering System

There are two dewatering pits located between units 2 and 3within machine bay 3 respectively units 4 and 5 within machine bay 5. The two dewatering pits are linked via the drainage gallery. In the overflow weir from the drainage gallery to the drainage pit, slide gates will be provided to allow all water to be diverted to one drainage pit while maintenance is carried out on the other drainage pit.

Turbine Dewatering System

The turbine dewatering system is designed to depress the water level in the runner chamber to dewater the runner for pump start and for synchronous condenser operation (SCO) in pump or turbine operation. That means the runner spins completely in air.

It consists of water-cooled compressors, air receivers and other equipment shown on the P&I diagrams. The air supply for the Turbine Dewatering System will be equipped with six (6) air compressors that supply twelve (12) accumulator tanks for six units. The air compressors are installed in two separate compressor rooms.

Oil Separator System

There are two transfer pits in the machine hall located below MIV-floor. One is between unit 1 and 2 and another pit in between unit 3 and 4 on EL 427.30. Above each transfer pit there´s the oil water separator and its main equipment located on EL 430.80. A dirty water collector pipe collects the separated water from the oil separators of the transformers and the oil contaminated water from the floor drains by gravity and leads it into both oil separator rooms