Where flanges are used in data center cooling
A liquid-cooled data center moves heat from the chips to the atmosphere through a chain of water circuits. The flange specification changes along the way, from carbon steel waterworks flanges at the cooling towers to clean 316L at the rack manifolds.
The cooling chain, from heat rejection to the rack
Supply, cooler water to the racksReturn, warmer water to the plant
- Heat rejectionCooling towers, dry coolers, condenser water pumpsA105, A350 LF2
AWWA C207, B16.5 Class 150
Flat face to cast iron pumps - Chiller plantChillers, primary and secondary pumps, headersA105, 304L, 316L
B16.5, B16.47, AWWA C207
Weld neck, slip-on, blind - Facility waterMains from the plant to the white space and CDUsA105 or 304L/316L
B16.5 Class 150, B16.47
4 to 48 in mains - Coolant distribution unitHeat exchanger between facility water and the IT coolant316L, 304L
B16.5 Class 150
Pickled and passivated - Technology coolingRow manifolds to racks and cold plates316L stainless
Class 150 WN, SO, lap joint
Clean, PMI checked
Systems
Chilled water systems
Plant rooms, headers and facility water mains. A105 and stainless, Class 150 and PN16.
CHW, FWSCondenser water and cooling towers
Large, low pressure mains to towers and dry coolers. A105, LF2 and AWWA C207.
CW, heat rejectionCoolant distribution units
Stainless flanges and stub ends for CDU builders and skid fabricators.
CDU, FWS to TCSTechnology cooling system (TCS)
The clean secondary loop to the racks. 316L, pickled and passivated, crevice-free joints.
TCS, SFN, DLCWhat changes from loop to loop
| Factor | Heat rejection and chilled water | Facility water to CDUs | Technology cooling system |
|---|---|---|---|
| Fluid | Treated water, sometimes glycol | Treated water or glycol | Inhibited water or PG25 |
| Wetted metal | Carbon steel common | Carbon or stainless steel | Stainless steel and copper alloys only |
| Usual standard | B16.5 Cl 150, B16.47, AWWA C207 | B16.5 Cl 150, EN 1092-1 PN16 | B16.5 Cl 150, EN 1092-1 PN16 |
| Cleanliness | Normal construction practice | Flushed and treated | Pickled, passivated, flushed to low conductivity |
Read the guide to facility water and technology cooling loops for the definitions behind this table.