Material Selection for Penstocks in Hydropower Plants Using a Multi-Criteria Decision-Making Approach

In hydropower plants, penstocks are used to convey water from a reservoir or dam to the turbines, where the water's kinetic energy is converted into mechanical energy. The material selection for penstocks is crucial to ensure their durability, resistance to corrosion, and ability to withstand highpressure water flow. Several factors influence the choice of materials for penstocks Penstocks must be able to withstand high water pressures without failure. Therefore, materials with high strength and durability are preferred. Commonly used materials include steel alloys such as carbon steel, high-strength low-alloy (HSLA) steel, and stainless steel. Since penstocks are constantly exposed to water, they are susceptible to corrosion. Corrosion can weaken the structure and decrease its lifespan. Materials that exhibit excellent corrosion resistance, such as stainless steel or corrosion-resistant all oys (CRAs), are often chosen to mitigate this issue. Penstocks are typically fabricated by welding sections together. Therefore, the material should possess good weldability to ensure proper construction and maintenance. Carbon steel and stainless steel are commonly selected due to their favorable welding characteristics. The cost of materials plays a significant role in the selection process. While stainless steel and CRAs offer excellent corrosion resistance, they are often more expensive than carbon steel. Thus, the project budget and cost-effectiveness considerations may influence material choices. It's important to note that the selection of penstock materials is typically carried out by engineering professionals, taking into account the specific project parameters and requirements. They perform detailed analyses, considering factors like pressure ratings, material properties, and cost-effectiveness, to arrive at the most suitable material choice for each project. The research significance of penstock material selection in hydropower plants lies in its ability to ensure structural integrity, enhance performance, and mitigate corrosion-related challenges. The choice of materials directly impacts the safety and reliability of the penstocks, which are critical components in hydropower systems. By conducting research on penstock materials, engineers and researchers can identify and evaluate materials that exhibit high strength, durability, and resistance to corrosion. Furthermore, research on penstock materials also explores innovative and advanced materials, such as composite materials or new alloy formulations that could offer improved performance characteristics. These materials may exhibit superior strength, corrosion resistance, or other desirable properties that can enhance the efficiency and lifespan of penstocks. WASPAS (Weighted Aggregated Sum Product Assessment) is a multicriteria decision-making (MCDM) method used to evaluate and rank alternatives based on multiple criteria. It is a widely used technique in various fields, including engineering, management, and decision sciences. Poly vinyl chloride (PVC), High-density polyethylene (HDPE), Glass reinforced plastic (GRP), Mild steel (MS) yield strength (YS), life (L), thickness (T), material cost(C), maintenance cost (MC) This result states” Rank” the of penstocks material selection in hydropower plants. Where First Rank is secured by GRP and last rank is secured by PVC whereas MS scored second one and HDPE followed it at third position.