Manifold Topics Infra Mechanical and Thermal Team Glenn Charest & John Fernandes

Data Center Source Liquid What ΔT ranges or flow rates does the solution need to support? What liquid types need to be supported? What DC supply pressure ranges are industry standard that we should account for?

LC Connection Types We realize we will need more than one option for QC’s (quick connectors) due to varying implementations and flow rates. However, the goal is to agree on a small subset of connection types and sizes to minimize cost (leverage volumes across the industry) and minimize complexity . Another goal is to have multi-source supplier agnostic QC solutions. QC’s to CDU QC’s to IT gear QC’s to DC source What materials are recommended (metal, plating, O-ring materials, etc..)?

Connection Locations Connection (Plumbing) Locations to DC: What locations in rack are connections from rack to DC preferred? Are top and bottom of rack connections acceptable? Connection (Plumbing) Locations to CDU: What locations in rack are connections from manifold to CDU preferred? Recommendation is to have CDU’s in bottom of rack and have connections on bottom side of manifolds.

Manifold Sizes & Mfg. Processes Prefer to use standard extrusions available in industry Suggested sizes/volume of manifolds? Manifold and IT gear machining for QC’s can be costly, are there specific QC attachment methods that have proven to be the most cost effective or are less prone to leaks? What is acceptable space between manifolds and busbar for service access (fans etc.) In ORV3 layout now, if we use 30mm wide manifolds with small gaps between hot and cold, 2 x 60mm fan trays are likely the widest can support 30mm x 50mm: Support ~70LPM flow with minimal flow variation across loops (42 post) Recommended high quality manifold manufacturers? Secondary process(es) for condensation mitigation? Head space requirement for fluid expansion? ~12PSI at 70LPM Less than 0.05LPM variation across 42 IT loops

Mate Forces Quick Connector mate forces can be fairly large. Estimated mate loads can be >30lbs per QC pair (@20PSI manifold pressure); this in addition to force needed to install chassis into rack. These forces may require inject/ejector levers to overcome these loads. If manifold pressures are higher, the larger the mate forces become. These forces may require inject/ejector levers to overcome these loads. What have others seen in real world mate forces and loads due to QC’s and varying manifold pressures. If DC liquid pressures are high, concerns arise with connection install forces. Have folks dealt with high connection/fitting loads? How have the loads been overcome?

Chassis to Manifold Registration Spring-loaded mechanisms will likely be need to ensure QC’s maintain full mating to counteract rack and chassis tolerances. As the QC’s de-mate, the valves start to close and increase pressure drop. Floating features are also a likely requirement to prevent the QC’s from “fighting the IT gear” due to rack tolerances & chassis. We don’t want the QC’s to carry the load of the it gear in the lateral and vertical directions. Some method of guiding the connections to align will need to be designed (guide pins, etc..) Looking for suggestions and solutions from the industry for this. What have been the challenges found in ensuring fully seated QC’s and floating/guidance? Larger vs. smaller QC’s have different mated depths and will require different mating gaps that will need to be handled by IT gear side. Suggestions with regards to ‘containment’ near QC-to-pipe transition on the chassis-side?

In-Rack CDU What are acceptable space/size for CDU? Recommended ΔT ranges or flow rates for CDU? CDU placement preference in rack? We recommend bottom of rack due to weight and CDU to manifold connections. CDU connections to manifold (size, location, type)?

Serviceability/Mounting With manifolds likely to be pre-filled with liquid, the rack support structure must be strong to support the weight and mate forces discussed earlier. This will add weight during servicing. The priority will be structural strength and location precision for the attachment method. Any suggestions or preferences for manifold to rack attachment method? Current plan is to have the manifolds mounted in the right rear of the rack (looking from the rear) Goal is to have service be from the rear. May require IT gear to slide forward ~1FT/.3M to access attachment screws.