Data Center Liquid Cooling Manifolds
Liquid cooling manifolds distribute and collect coolant across multiple server connections within a rack or row. They form the central distribution point of a rack-level cooling loop, connecting the CDU supply and return circuits to individual server cold plates via QDC couplings or hose assemblies.
How It Works
A rack manifold typically consists of a supply header and a return header, each with multiple outlet ports corresponding to the number of servers or cooling circuits in the rack. Coolant from the CDU enters the supply manifold, is distributed to each server cold plate, and returns through the return manifold back to the CDU. Flow balancing — either through fixed orifices or adjustable valves — ensures each server receives adequate coolant flow regardless of its position in the rack. Manifolds are designed for the specific rack height, port count, and connection type of the target installation.
Applications
- Rack-level coolant distribution for direct-to-chip cooling
- Row-level supply and return headers for multiple racks
- CDU supply and return circuit interface
- Multi-server GPU rack cooling infrastructure
- AI accelerator platform cooling loops
- HPC cluster rack cooling
- OEM liquid-cooled rack and server systems
- Modular data center cooling infrastructure
Key Technical Specifications
| Configuration | Supply + return pair, single-piece or modular |
| Port Count | 4 to 24 ports per manifold; custom available |
| Port Sizes | G1/4" to G1" and NPT equivalents |
| Materials | Stainless steel 316L, aluminum 6061, copper |
| Working Pressure | Up to 16 bar |
| Temperature Range | -20°C to +150°C (material dependent) |
| Flow Balancing | Fixed orifice or adjustable needle valve options |
| Mounting | Rack rail, DIN rail, panel mount, custom bracket |
| End Connections | Threaded, compression, push-fit, flanged |
| Surface Treatment | Passivation, anodizing, electropolishing options |
| Certifications | Options available depending on configuration and manufacturing partner. Please specify project requirements. |
Specifications are indicative. Final parameters depend on manufacturing partner and project configuration. Contact us with your specific requirements.
Available Configurations
- Rack-height manifold pairs (1U to 42U rack coverage)
- Modular manifold sections for scalable port count
- Integrated flow balancing valves per port
- Pressure gauge and temperature sensor ports
- Drain and fill ports for system commissioning
- QDC socket integration for tool-free server connections
- Hose barb or compression fitting ports
- Custom port spacing to match specific rack equipment layout
Materials
Operating Conditions
- Working pressure: up to 16 bar — confirm with manufacturing partner
- Temperature: -20°C to +150°C — dependent on material and seal selection
- Fluid compatibility: water, glycol/water, dielectric fluids — confirm chemistry
- Rack environment: designed for 19" or 21" rack mounting
- Vibration: specify if rack is subject to seismic or transport vibration requirements
Selection Guide
Manifold selection depends on: (1) Port count — match to the number of servers or cooling circuits in the rack; (2) Port size — determined by required flow rate per circuit and allowable pressure drop; (3) Material — stainless steel for corrosion resistance, aluminum for weight reduction, copper for thermal applications; (4) Flow balancing — fixed orifices are simpler and lower cost; adjustable valves allow field balancing for mixed server configurations; (5) Mounting — confirm rack rail compatibility and available space; (6) End connections — match to CDU supply/return pipe size and connection type.
OEM & Custom Manufacturing
Custom manifold designs are available for OEM equipment manufacturers and system integrators. Custom options include non-standard port counts and spacing, proprietary connection interfaces, integrated sensor ports, custom materials for specific coolant chemistries, and private label manufacturing. Provide your rack layout drawing and flow requirements for a design review.
Submit Custom RequirementQuality & Testing
Manifolds for data center liquid cooling require pressure testing, leak testing, and cleanliness verification before installation. Hydrostatic pressure testing to 1.5× working pressure is standard practice. Cleanliness specifications — including particle count and flush requirements — should be specified for cold plate and CDU protection. Certification options are available depending on configuration and manufacturing partner.
Frequently Asked Questions
How many ports does a rack manifold typically have?
Port count depends on the number of servers in the rack. A standard 42U rack with 1U servers could require up to 42 ports per manifold, though in practice most AI GPU racks have fewer, higher-density servers. Common configurations range from 4 to 16 ports. Custom port counts are available.
What is flow balancing and why is it important?
Flow balancing ensures each server in the rack receives adequate coolant flow. Without balancing, servers closer to the manifold inlet receive more flow than those further away. Fixed orifices provide passive balancing; adjustable needle valves allow field adjustment for racks with mixed server types or varying heat loads.
Can manifolds be used with both water and glycol/water coolants?
Yes. Stainless steel 316L manifolds with appropriate seal materials are compatible with both deionized water and glycol/water mixtures. The glycol concentration and inhibitor chemistry should be confirmed with the manufacturer to ensure seal compatibility.
Are custom manifold lengths available for non-standard rack heights?
Yes. Custom manifold lengths, port spacing, and port counts are available for non-standard rack heights or equipment layouts. Provide your rack drawing and server layout for a custom design review.
Need Liquid Cooling Manifolds for Your Project?
Send your connection size, coolant type, flow requirements and estimated quantity. Our team will review the application and identify suitable manufacturing options.