A manifold is the most nozzle-dense piece of pipe on the project and the one most likely to be built wrong in the field. Buy it as a tested assembly with its valves on.
Sourcing manifolds & headers for a data center project? Call 601.892.5017 or email collin.t@fabtekindustries.com — send the drawings and the spec and we quote to print.
- Specify manifolds from the isometric plus the valve schedule plus the equipment layout; nozzle spacing is checked against the racks, not just the drawing.
- Decide whether valves are installed by the fabricator and included in the hydrotest; they should be.
- Stainless technology-loop headers need a cleanliness and passivation spec; write it in.
- Tag each branch to its equipment tag, not just the manifold number.
What you are buying
Distribution manifolds split a hall's supply and return into branches for CDUs, in-row coolers or rear-door exchangers; plant headers collect and distribute at the chillers and pumps; CDU and rack-row headers carry the technology loop to the racks. Each is a large-bore barrel with branch nozzles, isolation and balancing valves, instrument taps, drains, vents and flanged or grooved ends, on welded saddles or stands. Carbon steel for facility water, stainless for technology loops. The mechanical engineer sizes and lays them out; the fabricator welds, tests and tags them.
Where it sits in the project
Mechanical contractors and developers buy manifolds to cut field welding at the busiest point in the room; cooling-equipment OEMs buy headers to complete their packages. Manifolds ship with the spools for their area or built into a pre-piped skid or prefabricated MEP module, and they are needed before the equipment they feed can be connected.
What to put in the RFQ
| Isometric and layout | Manifold iso with nozzle spacing and orientation, plus the rack or CDU layout it serves |
|---|---|
| Materials | Carbon steel or stainless grade, barrel and branch sizes, schedule, end types |
| Valves and taps | Valve schedule by branch: isolation, balancing, drain, vent, instrument; owner-furnished or fabricator-procured |
| Code and test | B31.1 or B31.3; hydrotest pressure and hold; witness points |
| Cleanliness | Internal cleaning, passivation of stainless, capping and bagging for technology-loop headers |
| Supports | Saddles, stanchions or wall brackets shipped with the assembly |
| Tagging | Manifold number plus equipment tag on each branch; delivery by area |
How to qualify a fabricator
- Stainless capability. A separate stainless cell, GTAW procedures and passivation through a qualified partner.
- Nozzle-spacing verification. Ask how branches are checked against the equipment layout before welding.
- Valve installation and test. Valves installed, oriented and included in the hydrotest.
- Skid integration. A fabricator who builds the skids and spools can deliver the manifold inside them.
Lead time, sequencing and delivery
Manifolds release with the spool package for their area, once the equipment layout is frozen; the nozzle positions depend on it. Ship capped, bagged where cleanliness is specified, on supports, tagged by branch, with the spools they connect to.
Common mistakes
- Welding before the layout is final. A branch that misses its CDU by a foot is a field cut and a re-weld.
- Valves shipped loose. Field-installed valves are not in the hydrotest and often not oriented right.
- Skipping the cleanliness spec on stainless. Debris in a technology loop ends up in a cold plate.
- One tag per manifold. The crew needs to know which branch goes where.
How FabTek supplies it
FabTek fabricates manifolds and headers in carbon and stainless at its Hazlehurst, Mississippi plants with Section IX welders, hydrotested with valves installed, and ships them with the spools for the area or built into pre-piped skids and prefabricated MEP assemblies.
Frequently asked questions
What is a chilled water distribution manifold?
A large-bore header with a row of valved branch connections that splits one supply or return main into the individual feeds for CDUs, in-row coolers or rack rows, usually with drains, vents and instrument taps.
Should manifolds be carbon steel or stainless?
Facility-water manifolds are commonly carbon steel; technology-cooling-system headers that touch the rack loop are commonly stainless with a cleanliness and passivation requirement. The specification governs.
Should the fabricator install the valves?
Yes where the design allows. Factory-installed valves are oriented correctly, included in the hydrotest and arrive ready to connect.
Who fabricates manifolds for data center liquid cooling?
FabTek Industries fabricates distribution manifolds, plant headers and CDU headers at its Mississippi plants for mechanical contractors, developers and cooling-equipment OEMs, tested and tagged by branch.
