OCP Cooling Environments: Cold Plate Sub-Project Design Specification, Universal Quick Disconnect (UQD), v2.0.0 (effective September 22, 2026)

Overview

The specification covers couplings used in non-combustible single-phase (water and glycol) technology cooling system (TCS) loops for electronics liquid cooling. Version 2.0.0 merges the earlier separate UQD Rev 1.0 and UQDB Rev 1.0 documents, to ease adoption and to give parity of key performance parameters across sizes and configurations. Authors are Mark Sprenger, Jordan Johnson and Bret Henkel (Intel) for version 1 and Travis Gaskill, Elizabeth Langer (CPC) and Paul Artman (AMD) for version 2.

The dimensional chapter tabulates socket and plug dimensions for sizes 02, 04, 06 and 08, UQDB socket and plug dimensions and terminations. For blind-mate couplings the connected length (panel to panel, excluding termination length) is nominally 36.1 mm for size 02 and 51.4 mm for size 08 (50.9-51.9 mm). Hybrid applications need extra compliance mechanisms (a floating device) for overdrive and radial offset, outside cross-verification testing. Terminations are given as ORB stud ends per ISO 11926-3 (for example ORB-04, 7/16-20 UNF-2A for size 02) or push-lock hose barbs (1/4 to 5/8 in), and sealing surfaces are machined to 32 Ra maximum.

The performance table sets, for all sizes, a maximum operating pressure of 6.89 bar(g) (100 psig) and a minimum burst pressure of 20.68 bar(g) (300 psig). Rated flows are 2.27 L/min for size 02, 6.44 for 04, 11.36 for 06 and 17.79 for 08; general maximum-flow guidance is the volumetric flow at 5 m/s through the minimum cross-section. Cv ranges are 0.30-0.43 for 02, 1.1-1.6 for 04, 2.2-3.3 for 06 and 3.6-5.6 for 08. Maximum coupling force at zero pressure is 55, 65, 90 and 135 N. At least 5,000 coupling cycles are required with maximum fluid loss per cycle of 0.02, 0.03, 0.04 and 0.07 mL. Operating temperature is 5-65 C, non-operating and shipping -40 to 70 C, storage life 5 years and service life 10 years.

The verification chapter defines property tests (pressure, leakage, coupling force, flow and pressure drop) and shipping temperature cycling plus operating-temperature and mechanical cycling tests. Suppliers must cross-validate their parts with at least 3 other suppliers, publish the list of suppliers they have passed with, and use at least 3 samples per test in line with ISO 18869. Wetted materials must be compatible with the acceptable materials in OCP's water-based and propylene-glycol fluid guidelines, and plug and socket surfaces in forceful contact must use defined similar-hardness materials such as SUS 303/304/304L/316/316L. Appendices cover version interchangeability, quality guidelines and supplier verification report templates.

Key points

1. Scope is limited to non-combustible single-phase (water and glycol) TCS loops for electronics liquid cooling.
2. Version 2.0.0 merges UQD and UQDB Rev 1.0, stays backward compatible and covers sizes 02, 04, 06 and 08.
3. Blind-mate (UQDB) connected length is nominally 36.1 mm for size 02 and 51.4 mm (50.9-51.9 mm) for size 08.
4. All sizes are rated for a maximum operating pressure of 6.89 bar(g) (100 psig) and a minimum burst pressure of 20.68 bar(g) (300 psig).
5. Rated flow by size: 02 = 2.27 L/min (0.6 gpm), 04 = 6.44 (1.7 gpm), 06 = 11.36 (3.0 gpm), 08 = 17.79 (4.7 gpm); the maximum-flow guidance corresponds to 5 m/s through the minimum cross-section.
6. Cv ranges: 0.30-0.43 for size 02, 1.1-1.6 for 04, 2.2-3.3 for 06 and 3.6-5.6 for 08.
7. Maximum coupling force at zero pressure is 55, 65, 90 and 135 N by size, scaling with pressure.
8. Couplings must survive at least 5,000 connect cycles, losing no more than 0.02-0.07 mL of fluid per cycle depending on size.
9. Operating range is 5-65 C, non-operating and shipping range -40 to 70 C, storage life 5 years and service life 10 years.
10. Suppliers must cross-validate with at least 3 other suppliers and publish the list of those passed.

Using it in design

• Select size (02-08) by rack or server loop flow: rated flows run from 2.27 to 17.79 L/min; estimate pressure drop from the Cv range and ask for correction or extra testing where the fluid differs from water.
• Specify manifold and server-side ports to ISO 11926-1 and terminations as ISO 11926-3 ORB stud ends or push-lock hose barbs, and design the floating (overdrive) mechanism separately for blind-mate applications.
• For racks with many connections, compute total connect force from the 55-135 N zero-pressure base plus the pressure scaling factor and compare it with server insertion force.
• Check line pressure against the 6.89 bar(g) operating and 20.68 bar(g) burst limits, and compare operating temperature with 5-65 C and shipping with -40 to 70 C.
• In procurement request the cross-verification reports, the list of suppliers passed, and the 5,000-cycle and per-cycle fluid-loss results, and verify wetted-material compatibility with OCP's fluid guidelines.

Who should read it

Engineers designing cold-plate racks, servers and manifolds, and quick-disconnect suppliers and procurement teams.

Document contents

1. License
2. Compliance with OCP Tenets
3. Version Table
4. Terms & Definitions
5. Scope
6. Overview
7. Interchangeability with Previous Versions
8. Connected Length Coupled State
9. Feature & Dimensional Requirements
10. UQD Socket Dimensions
11. UQD Plug Dimensions
12. UQDB Socket Dimensions
13. UQDB Plug Dimensions
14. Terminations
15. Performance Requirements
16. Performance Verification Tests
17. QD Property Tests
18. Thermal / Mechanical Cycling Tests
19. Supplier Cross-Verification Testing
20. Marking & Packaging Requirements
21. Wetted Materials
22. Safety & Regulatory Requirements
23. References
24. Appendix (version interchangeability, quality guidelines, reporting templates)

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Publication details

Authors

Travis Gaskill; Elizabeth Langer; Paul Artman; Mark Sprenger; Jordan Johnson; Bret Henkel

Publisher

Open Compute Project Foundation

Year

2026

Document language

English

Source type

Industry body

Access

Open licence — downloadable

Licence

OWFa 0.9 — Open Compute open specification licence; redistribution permitted

Licence evidence

www.opencompute.org

Citation