Data Center Cooling
Nickel Alloy in Liquid Cooling — Only Where 316L Is Not Enough
Industry Overview
Setting expectations first: the CDU core loop in an NVIDIA NVL-class data centre is specified in 316L electropolished tube, and TOKO ALLOY does not supply 316L. We will not pretend otherwise. What we can supply is the small set of components downstream of that specification where 316L is the weak point: brazed and welded heat-exchanger cores in high-chloride make-up water, corrosion-resistant valve and pump trim, and high heat-flux cold-plate hardware in aggressive-water locations. If your project is a standard CDU loop, buy 316L from a stainless supplier — that is the correct engineering answer, and it is also what the platform vendor mandates.
Key Challenges
Make-Up Water Chloride in Hot Climates
Middle East and Gulf sites routinely run cooling make-up water at several hundred ppm chloride, which concentrates two to four times across evaporation cycles. At that point 316L is at the edge of its pitting margin in the hottest parts of the loop — this is the specific case where a nickel alloy is justified.
Brazed Plate Heat Exchanger Cores
Facility-water heat exchangers are the highest-chloride, highest-temperature point in a liquid-cooled facility. Corrosion here contaminates the whole secondary loop with particulate, which is far more damaging than the exchanger failure itself.
Ultra-Cleanliness Requirements
Cold-plate micro-channels of 0.3–1.0 mm block on particulate above roughly 150 µm. Any alloy substitution has to hold the same internal surface finish, cleanliness and helium leak-tightness as the 316L it replaces — the corrosion argument alone is not sufficient.
Traceability at Hyperscale
A 100 MW facility consumes tens of tonnes of wetted material across multiple construction zones on a 14-month schedule. Heat-number traceability and lot consistency matter as much as the alloy itself.
TOKO ALLOY Solutions
Inconel 625 for High-Chloride Exchanger Tube (N06625)
ASTM B704/B705 tube for facility-water and make-up-water heat exchangers where chloride concentration would pit 316L. PREN > 45, and the same bright-annealed surface finish route used for high-purity tubing.
Monel 400 for Marine and Brackish Cooling (N04400)
ASTM B163 tube for coastal and seawater-cooled facilities — high resistance to flowing seawater at the velocities plate-and-frame exchangers run.
Hastelloy C-276 for Treated-Water and Dosing Skids (N10276)
ASTM B622 small-bore pipe and B626 tube for biocide dosing, sidestream filtration and water-treatment skids, where hypochlorite or chlorine dioxide is present at full strength.
Alloy 718 and 625 Bar for Valve and Pump Trim (N07718 / N06625)
ASTM B637 and B446 bar for stems, seats and trim in high-chloride loops — the components that fail first when the wetted material is under-specified, and the cheapest place to add corrosion margin.
Recommended Materials Data Center Cooling
View detailed chemical composition, mechanical properties, and corrosion resistance data for each recommended grade:
Related Products
Need Piping Solutions for Data Center Cooling?
Tell us about your project requirements and we will recommend the optimal material and product specification.
Request Quote