Flanges for Data Center Cooling Systems

By material

The loop decides the material. Carbon steel is standard on condenser water and most facility water mains. Stainless steel is required wherever the coolant reaches the IT equipment, because rust particles from carbon steel would foul cold plates.

Stainless steel flanges

304L and 316L for CDUs, TCS loops and stainless mains. Pickled and passivated on request.

ASTM A182 F304L · F316L

Carbon steel flanges

A105 and A350 LF2 for chilled water, condenser water and facility water mains.

ASTM A105 · A350 LF2 · A516-70

By standard

Most data center piping specs call up ASME B16.5 Class 150 in North America, the Middle East and Asia, and EN 1092-1 PN16 in Europe. Mains above 24 inches move to ASME B16.47 or to AWWA waterworks flanges.

ASME B16.5

NPS 1/2 to 24, Class 150 and 300. The default for data center mechanical piping.

Class 150 · RF · FF

ASME B16.47

Series A and B weld neck and blind flanges, NPS 26 to 60, for large headers.

Series A · Series B

EN 1092-1

PN10, PN16 and PN25 flanges for European data centers, from a PED certified manufacturer.

PN16 · Types 01, 05, 11

AWWA C207

Steel ring, hub and blind flanges for large chilled and condenser water mains.

Class B · D · E · F

AWWA C228

Stainless ring slip-on and blind flanges for large stainless water mains.

Class SA to SF

By flange type

Weld neck flanges

Butt welded with a smooth bore. First choice on TCS headers and equipment nozzles.

WN · RF · FF

Slip-on flanges

Economical, easy to align. The workhorse on carbon steel water mains.

SO · SORF · Type 01 / 12

Blind flanges

Header ends, future phase tie-ins, flushing and hydrostatic test points.

BL · RF · FF

Lap joint and stub ends

Only the 316L stub end is wetted; the loose flange rotates for easy alignment.

B16.9 · MSS SP-43

Flat face flanges

For cast iron chillers, pumps and valves, and FRP cooling tower connections.

FF · full-face gasket

Quick selection by loop

A starting point for the piping spec. Your design pressure, temperature and the mating equipment decide the final choice.

Typical flange selections in a liquid-cooled data center
Loop or system	Usual material	Usual standard and class	Face	Common types
Condenser water and cooling towers	Carbon steel A105; A350 LF2 where it is cold	ASME B16.5 Class 150; AWWA C207 Class D on large mains	RF; FF to cast iron	Weld neck, slip-on, blind
Chilled water plant and facility water mains	Carbon steel A105, or stainless 304L/316L	ASME B16.5 Class 150; B16.47 above 24 in; EN 1092-1 PN16	RF; FF at chillers and pumps	Weld neck, slip-on, blind
Coolant distribution units	Stainless 316L or 304L	ASME B16.5 Class 150; EN 1092-1 PN16	RF	Weld neck, slip-on, lap joint
Technology cooling system (TCS)	Stainless 316L, pickled and passivated	ASME B16.5 Class 150	RF	Weld neck, lap joint, blind

Racks of finished stainless steel flanges sorted by size in the RIC stores — Finished stainless flanges sorted by size and grade in our stores.

What every order includes

An EN 10204 3.1 inspection certificate with chemistry, mechanical results and heat treatment for each heat or lot.
Hard stamping of manufacturer, specification, grade, size, class and lot number on each flange.
100% visual and dimensional inspection, and 100% PMI on stainless steel.
Export packing in wooden cases. Third-party inspection by your nominated agency can be arranged.

Flanges for data center cooling systems