ORv3 Blind Mate Liquid Cooling Interfaces Overview & Update

Author: Glenn Charest, Engineer, Meta; Grace Piette, Engineer, Meta Collection: 2023 Global Summit - Cooling Environments

Summary

Glenn Charest and Grace Piette (Meta engineers) present the system-level overview and 2023 progress update for the OCP ORv3 Blind Mate Liquid Cooling project — a closed workstream developing a holistic liquid cooling solution for ORv3 racks that enables self-aligning blind-mate fluid connections when chassis are inserted. This presentation covers the system architecture, valve design, manifold design, and rack-level flow testing results. A companion presentation by Safeway/Wiwynn covers the component-level detail.

The ORv3 blind mate system uses a bolt-on liquid cooling kit added to a standard ORv3 rack. Hot and cold manifolds are positioned at the rear corners of the rack. IT chassis carry plug valves; the rack manifolds carry socket valves. When a chassis is inserted, the plug and socket self-align and mate without manual connection. The valve design includes an alignment cone, ISO threads, EPDM seal on the socket side, and a floating body on the plug side that accommodates both radial and angular misalignment. A novel injector mechanism with compound motion and long travel is used to develop the necessary force to engage and disengage the valves.

Key 2023 updates: a revised valve design (January 2023) with longer plug body increased leverage and dramatically smoothed the connection stroke. An interoperability build in early 2023 tested components from all four valve suppliers; results were mostly positive but identified some force and flow uniformity issues. A further build was completed in September 2023 to address remaining issues. Manifold design was updated to support both top and bottom connections and modular purge assemblies. A preliminary design document was published on the OCP wiki and the cold plate mailing list.

Rack-level flow testing across configurations of 4, 8, and 12 chassis with mixed QC vendors showed flow variation under 5% at up to 40 LPM. Pressure drop modeling predicts less than 3.5 PSI at 80 LPM. A larger pump is needed to test above 40 LPM directly; future testing planned with higher-capacity pump.