Quick answer: direct-to-chip systems use different piping at each level. Server loops and cold plates use copper and flexible hose (supplied with the hardware). Rack manifolds are typically stainless steel. Room and row distribution — the Technology Cooling System — is predominantly 304/316L stainless steel tube, chosen for coolant purity and design life; polymer (PP-H/PP-RCT) appears as an alternative. Facility water loops beyond the CDUs use stainless, carbon steel or polymer at building-services scale.
Walk the loop from the chip outwards and the material logic explains itself:
1. Inside the server
Cold plates (copper, sometimes nickel-plated) connect via short flexible hoses with quick disconnects. All of this ships with the IT hardware — nobody on the construction side procures it.
2. The rack manifold
Vertical stainless headers distributing coolant to each server. Usually OEM-supplied with the rack ecosystem.
3. Row and room distribution (TCS)
This is the contractor-procured scope, and where the material decision genuinely sits. Stainless steel — typically 316L sanitary tube with controlled internal finish — is the benchmark because the coolant it carries ends up in microchannels a fraction of a millimetre wide. Cleanliness, pressure headroom, warm-water tolerance and a 20-year life without de-rating are the drivers. Polymer systems compete here on weight and jointing speed; the trade-offs are covered in our stainless vs polymer comparison.
4. CDU connections
Demountable stainless joints — clamp fittings and unions — with butterfly valve isolation either side, so units can be serviced without draining the loop.
5. Facility Water System
Beyond the CDUs it’s conventional building services: larger-bore stainless (EN 10217-7 metric systems), carbon steel or polymer, flanged to plant.
The one-line specification most projects land on
316L stainless sanitary tube, hygienic internal finish, EN 10204 3.1 certified, orbital-welded, clamp-connected at serviceable equipment, butterfly valve isolation at branches — from the CDU inwards; pressure-rated stainless or alternatives outwards.
Neumo UK stocks that entire specification in one warehouse: see piping for direct-to-chip liquid cooling.
Talk to us about your project
Kevin Windsor — Product Manager, Data Centre Liquid Cooling
kw@neumo.co.uk · 01952 583 999