As the adoption of generative AI expands, demand for water- and liquid-cooled data centers is increasing in Japan. However, liquid-cooling systems require specifications and materials that differ significantly from conventional air-conditioning infrastructure, and domestic expertise remains limited. Additionally, concerns over water-leak risks have led many organizations to approach liquid cooling with caution. This seminar will introduce collaborative case studies among manufacturers of valves, hoses, and couplings, illustrating practical approaches to Direct Liquid Cooling (DLC) system design. By leveraging the strengths of multiple manufacturers and adapting to site-specific requirements, the seminar highlights the importance of optimal piping selection for the safe and efficient deployment of water-cooled data centers.