Liquid cooling
Liquid-Cooling Quick Disconnects: Suppliers, UQD, and Blind-Mate Options
A coupling choice starts with the interface family, the way it mates, and the fluid. Nominal size is one line of that request.
On this page
Specify the interface family, the mating method, the fluid and seal materials, and the operating conditions the design already uses. Two couplings with a similar body size can be hand-mate, blind-mate, or built to different documents. This comparison uses manufacturer pages and the Open Compute Project UQD specification v2.0.0, dated September 22, 2026. It is not a distributor list, and Rust Belt Industrials does not sell these parts.
What to specify before choosing a coupling
Write four things before you compare catalogs. First, the interface name and size code, such as UQD04 or UQDB04, plus the specification version if the design names one. Second, whether a person mates it by hand or the equipment mates it blind. Third, the fluid and the seal materials the design allows. Fourth, the temperature, pressure, and flow conditions that already govern the loop. A thread size or a hose barb, by itself, does not select the coupling.
UQD and blind-mate terminology
OCP's Universal Quick Disconnect Specification v2.0.0 defines UQD as the hand-mate universal quick disconnect and UQDB as the blind-mate version. Hand-mate means a person couples and uncouples the pair. Blind-mate means the pair is coupled by some other mechanism, without that direct alignment. The same document defines a hybrid as a blind-mate coupling of a UQD plug and a UQDB socket. The scope is non-combustible single-phase water and glycol systems for liquid cooling of electronics.
The specification's marking table uses the size codes 02, 04, 06, and 08, written as UQD02 v2 through UQD08 v2 and the matching UQDB codes. Version 2 is described as designed to be backwards compatible with the earlier separate UQD and UQDB specifications, and the text says end-user deployment assessment is encouraged. Risks of mixing version 1 and version 2 parts are placed in an appendix. That is a narrower statement than a rule that every brand and every series will mate.
Manually connected interfaces
CEJN's product page lists UQD02, UQD04, UQD06, and UQD08, in stainless steel, with double EPDM seals and a push-lock hose barb. An earlier CEJN article named only UQD-02 and UQD-04 and said couplings built to the UQD specification are connectable. The product page does not say whether those couplings are latched by hand or mated blind. JetCool lists UQD02, UQD04, UQD06, and UQD08 for hand insertion at the server node, and says they are designed per OCP specifications. Gates lists universal quick disconnect couplings on its data center cooling page and does not, on that page, publish the size codes. CPC's cold-plate page describes latched Everis couplings and does not use the name UQD. Separate Everis UQD pages do. The UQD02 page describes a latch and one-handed operation.
Blind-mate interfaces
OCP defines UQDB as the blind-mate coupling. JetCool lists UQDB02 through UQDB08, with blind insertion and a stated radial float of plus or minus 1 mm on that product description. Gates lists blind-mate couplings under the name UQDB and does not publish sizes on the family page. CPC's UQD08 page describes blind-mate configurations and also traditional socket and plug connections. Parker's July 2026 brochure labels UQDB as blind-mate in sizes 02, 04, 06, and 08. Danfoss describes a UQDB blind connection with 1 mm of radial compensation, lists size -04, and says sizes -02, -06, and -08 are coming soon. Amphenol's product page calls UQDB a self-aligning blind-mate connection and says Rev 2.0 supports a UQD plug in a UQDB socket.
Suppliers and published product families
Rows are alphabetical. A blank attribute means the page reviewed on October 16, 2026 did not state it. Parker's HTML product pages returned an access error. The July 2026 brochure is the Parker source used here. Ratings stay on the model page that states them, because the test conditions are not the same from one maker to the next.
| Supplier | Family on the page | Mating | Ends or materials stated | Source |
|---|---|---|---|---|
| Amphenol Industrial | UQD, UQDB, BMQC, LQC, MQD, and SHQD on the product page. Headquarters listed in Endicott, New York. | UQD is described as a manual connection. UQDB is described as blind mate. | Shell described as stainless steel. Seal options on the portfolio page include EPDM, FKM, and FMVQ, by series. A plant is not named. | Product page |
| CEJN | UQD02, UQD04, UQD06, and UQD08. North American address in Gurnee, Illinois. Plant city not stated. | Mating method is not stated on the product page. | Stainless steel (AISI 303). Double EPDM seals. Push-lock hose barb. | UQD couplings |
| CPC, cold-plate page | Everis couplings for cold-plate liquid cooling. Address listed in Arden Hills, Minnesota. | Latched and blind mate, plus straight and elbow bodies. | Plated brass, aluminum, stainless steel, and polymers. Seal options include EPDM and FKM. UQD is not named on this page. | Cold plate page |
| CPC, Everis UQD | UQD02, UQD04 with UQDB04, and UQD08 with UQDB08. UQD06 is not on these pages. | UQD02 describes a latch. UQD08 describes blind-mate and traditional connections. | Model pages name stainless housings and EPDM seals. Do not copy the cold-plate material list onto these models. | UQD family |
| Danfoss | Hansen UQD in four sizes. Corporate address on the fact sheet is Nordborg, Denmark. A plant is not named. | UQD is push-to-connect. UQDB is described as a blind connection. Size -04 is listed. Other UQDB sizes are described as coming soon. | Fact sheet: 303/304 stainless steel and peroxide-cured EPDM seals. Ends include ORB, BSPP, and push-on hose. | Fact sheet |
| Parker | UQD and UQDB, sizes 02, 04, 06, and 08, in a July 2026 brochure. A plant is not named. | Brochure labels UQD hand-mate and UQDB blind-mate. | Stainless steel and EPDM in the selection guide. UQDB plugs are also described with zinc-plated steel. Thread, Push-Lok, and hose barb options are printed. | July 2026 brochure |
| Gates | UQD couplings and UQDB blind-mate couplings, listed with cooling hoses. | The page names both hand-mate UQD and blind-mate UQDB products. | Sizes, seals, and end fittings are not on the family page. | Data center cooling |
| JetCool | UQD and UQDB sizes 02, 04, 06, and 08, developed by Coreworks. Address listed in Littleton, Massachusetts. | UQD for hand insertion. UQDB for blind insertion. | Bidirectional self-sealing is stated. Barb or port thread is not stated on this page. | Product page |
What changes the selection?
Fluid and seals come first. OCP v2.0.0 tells the supplier to use wetted materials compatible with OCP's water-based and propylene-glycol fluid guidelines. CPC says Everis seal options include EPDM and FKM and that the couplings are used with coolants that include dielectric fluids. A seal that is fine for one fluid is a question for the other. Ask for the compatibility statement for the fluid you will run.
Temperature, pressure, flow, and pressure drop need the model's conditions. This guide does not copy one maker's flow curve onto another. Leakage language also differs. CPC describes dry-break non-spill disconnection. JetCool describes a self-sealing design. OCP v2 requires visible size marking and, for hand-mate parts, a means of color identification with red and blue at a minimum. Those are specification requirements for parts built to that document, not a test result for every catalog coupling that uses the letters UQD.
Cleanliness and the installation envelope still change the part. A blind-mate coupling needs the alignment the equipment provides. A latched coupling needs a hand and a service clearance. Manifold pages and hose assemblies pick up the hardware on either side of the coupling.
How couplings fit into hoses and manifolds
CPC's cold-plate description places quick disconnects at the manifold and at the server or cold plate, with tubing between the cold plate and a heat exchanger. CoolIT's manifold page, linked from the manifold guide, says its manifolds can be fitted with hand-mate or blind-mate quick disconnects. The coupling, the hose, and the manifold each have a maker. Matching the interface family across those three is the purchasing task.
Questions to resolve with the supplier
Can brands be mixed?
CEJN's product page says any manufacturer's products are connectable when they follow the UQD specification. OCP v2.0.0 defines interface dimensions for interoperability and still tells the user to assess deployment when version 1 and version 2 parts are combined. Parker's July 2026 brochure says its UQD and UQDB couplings are fully interchangeable with other UQD-approved manufacturers. That line is the brochure's claim. Amphenol, JetCool, CPC, Parker, and Danfoss also sell series that are not the UQD hand-mate pair. Mixing those series is a separate question. Ask for the specification version, the size code, and a statement that covers the two part numbers you want to mate.
What does non-spill mean for the listed model?
It means what that model's document says. CPC uses dry-break and non-spill for Everis. The OCP specification discusses fluid-loss requirements for the UQD interface and points the test at water. Those are different texts. Ask for the spill or fluid-loss figure, the test fluid, and the document that contains it. A catalog adjective is not that figure.
Which tests and documents are needed?
Ask for the interface drawing or the specification revision, the materials list, the seal compound, the pressure and temperature range, and the leakage or fluid-loss statement. If the loop is supposed to follow OCP v2.0.0, say so. If the part is a CPC Everis model, name the model page, because the cold-plate description and the UQD model pages do not carry the same ratings.
Sources and comparison method
The OCP text used here is specification v2.0.0, with the date September 22, 2026 printed in the document. Manufacturer claims are limited to the pages linked below. No coupling was mated for this guide, and no cross-brand fit was assumed.