The liquid cooling pipeline is the channel through which the liquid coolant flows. The liquid cooling pipeline needs to participate in the flow-resistance distribution of the entire liquid cooling system and provide convenient connection interfaces for external liquid cooling equipment. Server liquid cooling pipelines are mainly used to connect cold plates and liquid cooling racks, primarily to carry heat away from the heat source through the pipes. Currently, pipelines are divided into non-metallic flexible hoses and metallic flexible hoses. Previously, the mainstream liquid cooling server pipelines mainly used non-metallic pipes such as EPDM, FEP, and PTFE. This year, NVIDIA's GB300 began to officially promote stainless steel corrugated metal pipes, allowing this pipeline solution to be adopted in mass production and becoming one of the mainstream solutions.
Many liquid load banks are also using stainless steel hoses now.
Recently, a major manufacturer of NVIDIA GB200/300 servers, in a report, provided a detailed comparison of the advantages and disadvantages of EPDM and stainless steel corrugated pipes for the first time. This comparison was based on the final test results of the GB200 and GB300 liquid-cooled servers.
EPDM hoses are a cost-effective solution, with core advantages including excellent flexibility, lightweight design, good vibration-damping capabilities, and low initial cost. This makes them easy to install in server chassis with limited space and complex wiring, and they can effectively absorb system vibrations.
However, their drawbacks are also significant: lower pressure resistance, the risk of coolant leakage, a relatively shorter lifespan, and potential material degradation after prolonged use. This leads to more frequent maintenance requirements and may occupy more space due to larger diameters. They are typically suitable for liquid cooling applications where cost is a primary concern and the workload is relatively standard.
Stainless steel corrugated tubing represents high performance and high reliability. Its core value lies in its excellent pressure and temperature resistance, extremely low permeability, ultra-long service life, and more compact diameter, providing stable, virtually maintenance-free long-term cooling for high-power density servers.
The trade-off is higher material and manufacturing costs, lower flexibility, and greater weight. Installation requires precise bending and reliable welding, and it may transmit mechanical vibrations. It is primarily intended for advanced liquid-cooled servers that demand ultimate cooling performance, reliability, and space efficiency.
Why does the GB300 start using stainless steel corrugated pipes for mass production?
Pressure resistance: EPDM rubber is very soft and flexible at normal temperature or low pressure, but it will experience creep and local bulging under continuous high pressure or repeated pressure pulsations; the metal corrugated pipe body is made of metal, which has high pressure resistance and stable elastic recovery, making it suitable for high-pressure/pulsating scenarios.
