Quick answer: a coolant loop is only as clean as its worst weld. Orbital TIG welding with internal argon purging produces smooth, oxide-free joints that match hygienic tube’s internal finish — and a disciplined flush, clean and passivation sequence at commissioning gets the loop to water-quality targets before a single server is energised. Specify both up front; retrofitting cleanliness into a live hall is miserable.
Why welds are the weak point
Hygienic tube arrives with a controlled bore, but every joint is a chance to undo it. Manual welds without purge leave “sugaring” — rough, oxidised beads inside the tube that shed particles, trap debris and seed corrosion. Multiply that by the hundreds of joints in a TCS loop and you’ve built a particulate generator upstream of your cold plates.
What good looks like
- Orbital TIG — a machine-rotated arc producing repeatable, full-penetration welds with consistent profile, joint after joint
- Internal purge — argon displacing oxygen inside the tube during welding, so the weld root stays bright and smooth
- Matched components — tube and fittings with consistent wall thickness (one reason to buy the loop’s tube and fittings from one range) so weld parameters stay stable
- Documentation — weld procedure specifications, welder qualifications, weld maps, and borescope inspection on a sampled or critical basis
This is standard practice for pharmaceutical and food-industry fabricators — which is exactly the labour pool experienced in it, and why hygienic-industry supply chains are moving into data centres.
Commissioning: the sequence that protects the chips
- Flush at high velocity to carry construction debris out through temporary strainers — smooth-bore tube reaches particle-count targets in fewer passes
- Chemical clean to remove oils and residues
- Passivate so the stainless surface’s protective oxide layer is uniform from day one
- Fill and dose with the specified coolant (e.g. PG25) and verify inhibitor levels
- Baseline water quality, so drift is detectable for the next 20 years
Each avoided flushing cycle is programme days back. On fast-track AI builds, that’s the quiet argument for specifying internal finish and weld quality together: they’re bought once, at design stage, and they pay at commissioning.
Neumo supplies orbital-weldable tube and matched fittings with full 3.1 traceability: stainless steel tube · fittings & flanges.
Talk to us about your project
Kevin Windsor — Product Manager, Data Centre Liquid Cooling
kw@neumo.co.uk · 01952 583 999