Liquid Cooling Manifold
System Overview
The HD-MF manifold takes one supply and one return line from the CDU and splits it into 4 to 12
balanced branches, one per server or per cold plate pair. It mounts inside the rack, behind the servers, and carries
the quick coupling interface that the hose assemblies plug into.
The header is fabricated from 316L seamless tube with orbital welds on every branch. Internal surfaces are pickled and passivated to Ra 0.8 micron or better, so no weld scale reaches the cold plate or the pump. Each branch can be fitted with a manual balancing valve, a temperature / pressure test port and a UQD or UQDB blind-mate coupling.
Manifolds are delivered pressure tested and labelled branch by branch, which removes the usual site guesswork about which drop feeds which server.
The header is fabricated from 316L seamless tube with orbital welds on every branch. Internal surfaces are pickled and passivated to Ra 0.8 micron or better, so no weld scale reaches the cold plate or the pump. Each branch can be fitted with a manual balancing valve, a temperature / pressure test port and a UQD or UQDB blind-mate coupling.
Manifolds are delivered pressure tested and labelled branch by branch, which removes the usual site guesswork about which drop feeds which server.
Basic Parameters
| Material | 316L (1.4404) seamless tube, orbital welded |
| Branch count | 4 / 6 / 8 / 10 / 12 |
| Branch coupling | UQD04, UQD08 or UQDB blind-mate |
| Main connection | DN25 / DN32 / DN40 threaded, flange or grooved |
| Working pressure | 1.0 MPa design, 1.5 MPa test for 30 minutes |
| Internal finish | Pickled and passivated, Ra ≤ 0.8 micron |
| Media | PG25 or deionized water, -20 to +65 °C |
| Leak test | Helium leak test ≤ 1x10-6 mbar.L/s on request |
| Branch accessories | Balancing valve, T/P test port, drip tray |
| Rack standard | 19 inch and OCP ORV3, 42U to 48U |
| Mounting | Rear rail bracket, serviceable from front and rear |
| Traceability | Heat number on each header, EN 10204 3.1 on request |
Values above are typical ranges. Final selection is confirmed against the project datasheet, flow rate, coolant and rack layout before order.
Balanced Flow at Every Branch
Branch valves are set on the test bench against the design flow of each cold plate, so the last server in the rack receives the same coolant flow as the first. Imbalance is the most common cause of hot GPUs in a liquid cooled rack.
Dripless Service
UQD quick couplings close both sides on disconnection. A server can be pulled for maintenance without draining the loop, and the spill is limited to the drop that stays inside the coupling body.
Clean Internal Surface
Orbital welding inside an argon purge, followed by pickling and passivation, keeps the loop free of scale. A rough internal weld is enough to clog a 0.5 mm cold plate channel within a few months of operation.
Application Notes
Order the manifold with the rack layout and the per-server flow rate, not just the branch count. Branch spacing has to
match the server pitch, otherwise hoses will cross and the rear of the rack becomes unserviceable. For blind-mate racks,
confirm the UQDB tolerance stack-up with the rack integrator before fabrication - the manifold is the fixed reference and the
server tray must land inside it.