Overview

General comment

Universal Quick Disconnect (UQD) blind-mate assembly for data center liquid cooling. Enables tool-free connection/disconnection of server trays to rack manifolds. The UQD standard was developed within OCP (Open Compute Project) as a global standard for spill-free quick couplings. Each tray requires a supply/return pair. The coupling body is modelled as machined from brass rod.

Technology: Fluid Connection, Blind-Mate Liquid Cooling
Geography: Global average data from equipment vendor specifications and industry literature

System boundary

The figure groups this dataset's unit processes by class. It is not a count of manufacturing steps — each process runs over as many passes as the flow requires, and those pass counts ship with the dataset.

Download this figure (SVG)

Data quality and references

Composite DQI 1.9 Very good

Reliability

2.5

Completeness

2.5

Temporal

1.3

Geographic

2.0

Technological

1.5

How the score is calculated: Constituent datasets have more influence when they contribute a larger share of the modelled cradle-to-gate energy demand.

Pedigree scores follow the ecoinvent data-quality matrix: 1 is the best attainable, 5 the weakest. The composite is their aggregate.

Sampling procedure: Component vendor specifications, academic papers, industry literature
Coverage status: Partial
Pedigree-scored source files: 4 — the source records behind this dataset's manufacturing operations. Each carries the five pedigree axes above; the composite DQI aggregates them.

Technosphere inputs

13 flows. Quantities are not published; they ship with the dataset on Circa.

Brass Materialkg · ±18.9%

Derivation basis: Calculated from per-operation consumption, operation counts, and manufacturing yield.
REEL derivation: engineering estimate of liquid-cooling manifold and quick-disconnect coupling mass and process inventory from vendor product data and the measured part geometry; no single published inventory covers these parts

The sources for this row are listed below.
Source citations (dataset-level): MGX Accelerated Computing Rack and Trays Specification 1.1
OCP UQDB Specification Revision 1.0
Background data: ecoinvent 3.12
Background dataset: brass
Notes: Purchased input grossed to fund the authored process loss booked as Brass Turnings (mass-closure funding; the retained mass is the product-side figure).
Uncertainty: ±18.9% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: kg

Stainless Steel Materialkg · -7.6% / +11.5%

Derivation basis: Calculated from per-operation consumption, operation counts, and manufacturing yield.
REEL derivation: engineering estimate of liquid-cooling manifold and quick-disconnect coupling mass and process inventory from vendor product data and the measured part geometry; no single published inventory covers these parts

The sources for this row are listed below.
Source citations (dataset-level): MGX Accelerated Computing Rack and Trays Specification 1.1
OCP UQDB Specification Revision 1.0
Background data: ecoinvent 3.12
Background dataset: steel, chromium steel 18/8, hot rolled
Notes: Purchased input grossed to fund the authored process loss booked as Stainless Steel Turning Swarf (mass-closure funding; the retained mass is the product-side figure).
Uncertainty: -7.6% / +11.5% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: kg

Helium Materialkg

Derivation basis: Calculated from per-operation consumption, operation counts, and manufacturing yield.
REEL derivation: engineering estimate of liquid-cooling manifold and quick-disconnect coupling mass and process inventory from vendor product data and the measured part geometry; no single published inventory covers these parts

The sources for this row are listed below.
Source citations (dataset-level): MGX Accelerated Computing Rack and Trays Specification 1.1
OCP UQDB Specification Revision 1.0
Background data: ecoinvent 3.12
Background dataset: helium
Uncertainty: No range defined.
Unit: kg

Synthetic Rubber Materialkg · -4.3% / +8.6%

Derivation basis: Calculated from per-operation consumption, operation counts, and manufacturing yield.
REEL derivation: engineering estimate of liquid-cooling manifold and quick-disconnect coupling mass and process inventory from vendor product data and the measured part geometry; no single published inventory covers these parts

The sources for this row are listed below.
Source citations (dataset-level): MGX Accelerated Computing Rack and Trays Specification 1.1
OCP UQDB Specification Revision 1.0
Background data: ecoinvent 3.12
Background dataset: synthetic rubber
Notes: Purchased input grossed to fund the authored process loss booked as Seal Moulding Flash (mass-closure funding; the retained mass is the product-side figure).
Uncertainty: -4.3% / +8.6% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: kg

Hardware Materialkg

Derivation basis: Calculated from per-operation consumption, operation counts, and manufacturing yield.
REEL derivation: engineering estimate of liquid-cooling manifold and quick-disconnect coupling mass and process inventory from vendor product data and the measured part geometry; no single published inventory covers these parts

The sources for this row are listed below.
Source citations (dataset-level): MGX Accelerated Computing Rack and Trays Specification 1.1
OCP UQDB Specification Revision 1.0
Background data: ecoinvent 3.12
Background dataset: steel, low-alloyed, hot rolled
Uncertainty: No range defined.
Unit: kg

Argon shield and purge gas Materialkg · ±35.1%

Derivation basis: REEL derivation: shielding and purge gas consumption per joint is a declared engineering estimate; no retrievable public document was identified for the adopted value

No source is attached to this row.
Source citations: Not stated
Background data: ecoinvent 3.12
Background dataset: argon, liquid
Uncertainty: ±35.1% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: kg

Citric acid Materialkg · ±33.2%

Source citations: ASTM A967/A967M, Standard Specification for Chemical Passivation Treatments for Stainless Steel Parts
Background data: ecoinvent 3.12
Background dataset: citric acid
Uncertainty: ±33.2% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: kg

Tungsten electrode wear Materialkg

Derivation basis: REEL derivation: tungsten electrode tip-dressing loss per joint is a declared engineering estimate; no retrievable public document was identified for the adopted value

No source is attached to this row.
Source citations: Not stated
Background data: proxy-mapped
Background dataset: tungsten carbide powder
Uncertainty: No range defined.
Unit: kg

Stainless Steel Bar Production Process activityg

Derivation basis: Specified for this manufacturing operation and scaled to the dataset's functional unit.

No source is attached to this row.
Source citations: Not stated
Background data: ecoinvent 3.12
Background dataset: section bar rolling, steel
Notes: Production of 303 SS bar stock
Uncertainty: No range defined.
Unit: g

CNC Turning (Stainless) Process activityg

Derivation basis: Specified for this manufacturing operation and scaled to the dataset's functional unit.

No source is attached to this row.
Source citations: Not stated
Background data: ecoinvent 3.12
Background dataset: chromium steel removed by turning, average, computer numerical controlled
Notes: Precision turning of coupling bodies
Uncertainty: No range defined.
Unit: g

CNC Turning (Brass) Process activityg

Derivation basis: Specified for this manufacturing operation and scaled to the dataset's functional unit.

The sources below come from the manufacturing operations behind this row.
Sources (inherited): Inherited, rolled up from the contributing process steps:

copper.org (date not recorded). Copper Development Association Inc., "Brass: The Cost-Effective Choice" (publication A7033), finished-part cost comparison for a screw-machined brass insert, built on 2014 production data from a Midwestern machine shop. PDF document.

copper.org (date not recorded). Kundig, K.J.A., "Free-Cutting Brass: A Closed Environmental Loop", Copper Development Association Inc., Innovations newsletter, July 1998.
Background data: ecoinvent 3.12
Background dataset: brass removed by turning, average, computer numerical controlled
Notes: Precision turning of the brass coupling bodies from rod
Uncertainty: No range defined.
Unit: g

Electricity, Global (GLO) ElectricitykWh · -19.6% / +20.5%

Derivation basis: Calculated from equipment energy across all manufacturing operations. This model includes no facility support, so the total is the manufacturing operations alone.
REEL derivation: engineering estimate of liquid-cooling manifold and quick-disconnect coupling mass and process inventory from vendor product data and the measured part geometry; no single published inventory covers these parts

The sources for this row are listed below.
Source citations (dataset-level): MGX Accelerated Computing Rack and Trays Specification 1.1
OCP UQDB Specification Revision 1.0
Background data: ecoinvent 3.12
Background dataset: electricity, medium voltage
Uncertainty: -19.6% / +20.5% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: kWh

Process water WaterL · ±50%

Derivation basis: Calculated from process-water and ultrapure-water demand across all manufacturing operations. This model includes no facility support, so the demand is the manufacturing operations alone. The fresh intake shown is that demand less the share reused under the water-recycling scenario this dataset assumes, and wastewater follows the same balance.

No source is attached to this row.
Source citations: Not stated
Background data: ecoinvent 3.12
Background dataset: tap water
Notes: Water demand from internal passivation, adjusted for assembly yield.
Uncertainty: ±50% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: L

Outputs and waste

Wastewater Wastewaterm3 · ±50%

Derivation basis: Calculated from the water balance: fresh-water input minus evaporation.

No source is attached to this row.
Source citations: Not stated
Background data: carried, no background dataset
Background dataset: No treatment route recorded for this output.
Uncertainty: ±50% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: m3

Stainless Steel Turning Swarf Solid wastekg · -28.6% / +42.9%

Derivation basis: Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

No source is attached to this row.
Source citations: Not stated
Background data: ecoinvent 3.12 treatment route
Background dataset: treatment of inert waste, sanitary landfill
Uncertainty: -28.6% / +42.9% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: kg

Brass Turnings Solid wastekg · ±30%

Derivation basis: Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

The sources below come from the manufacturing operations behind this row.
Sources (inherited): Inherited, rolled up from the contributing process steps:

copper.org (date not recorded). Copper Development Association Inc., "Brass: The Cost-Effective Choice" (publication A7033), finished-part cost comparison for a screw-machined brass insert, built on 2014 production data from a Midwestern machine shop. PDF document.

copper.org (date not recorded). Kundig, K.J.A., "Free-Cutting Brass: A Closed Environmental Loop", Copper Development Association Inc., Innovations newsletter, July 1998.
Background data: ecoinvent 3.12 treatment route
Background dataset: market for copper scrap, sorted, pressed
Uncertainty: ±30% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: kg

Seal Moulding Flash Solid wastekg · -33.3% / +66.7%

Derivation basis: Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

No source is attached to this row.
Source citations: Not stated
Background data: ecoinvent 3.12 treatment route
Background dataset: treatment of inert waste, sanitary landfill
Uncertainty: -33.3% / +66.7% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: kg

Spent brazing-filler dross Solid wasteg

Derivation basis: Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

No source is attached to this row.
Source citations: Not stated
Background data: ecoinvent 3.12 treatment route
Background dataset: treatment of hazardous waste, underground deposit
Uncertainty: No range defined.
Unit: g

Weld-rework grinding dust Solid wasteg

Derivation basis: Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

No source is attached to this row.
Source citations: Not stated
Background data: ecoinvent 3.12 treatment route
Background dataset: treatment of hazardous waste, underground deposit
Uncertainty: No range defined.
Unit: g

Rejected Assemblies Solid wastekg

Derivation basis: Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

No source is attached to this row.
Source citations: Not stated
Background data: ecoinvent 3.12 treatment route
Background dataset: treatment of inert waste, sanitary landfill
Uncertainty: No range defined.
Unit: kg

Emissions to air

2 elementary flows released to air by this dataset's own operations. Quantities are not published; they ship with the dataset on Circa.

Boron and silicon volatiles Emission to airg

Derivation basis: REEL derivation: trace boron and silicon volatiles from the brazing filler metal are a declared engineering estimate; no retrievable public document was identified for the adopted value
No corresponding ecoinvent dataset or flow was identified for this entry, so it is published with its own quantity and no background link

No source is attached to this row.
Source citations: Not stated
Compartment: Air
ecoinvent 3.12 elementary flow: Not stated
Uncertainty: No range defined.
Unit: g

Particulate matter (Cr, Ni, Fe oxides) Emission to airg

Derivation basis: REEL derivation: weld-fume particulate release per joint is a declared engineering estimate; no retrievable public document was identified for the adopted value

No source is attached to this row.
Source citations: Not stated
Compartment: Air (non-urban air or from high stacks)
ecoinvent 3.12 elementary flow: Particulate Matter, < 2.5 um
Uncertainty: No range defined.
Unit: g

Emissions to water

2 elementary flows released to water by this dataset's own operations. Quantities are not published; they ship with the dataset on Circa.

Iron Emission to waterg

Derivation basis: REEL derivation: free-iron release to the passivation bath is a declared engineering estimate; no retrievable public document was identified for the adopted value

No source is attached to this row.
Source citations: Not stated
Compartment: Water (surface water)
ecoinvent 3.12 elementary flow: Iron ion
Uncertainty: No range defined.
Unit: g

Chromium Emission to waterg

Derivation basis: REEL derivation: minor chromium release during citric-acid passivation is a declared engineering estimate; no retrievable public document was identified for the adopted value

No source is attached to this row.
Source citations: Not stated
Compartment: Water (surface water)
Formula: Cr3+
CAS number: 16065-83-1
ecoinvent 3.12 elementary flow: Chromium III
Uncertainty: No range defined.
Unit: g

Flows not quantified

4 flows are recorded for this dataset but carry no quantity — cut off below the significance threshold, or with no background dataset available. They remain inside the declared system boundary; each is listed with its reason.

Not modelled (4)

Alkaline degreaser Materialkg

Derivation basis: REEL derivation: alkaline pre-clean drag-out taken as a declared engineering estimate for a typical degreaser bath concentration; no retrievable public document was identified for the adopted value

No source is attached to this row.
Source citations: Not stated
Background data: not modelled
Background dataset: Not applicable: this flow is not quantified in the inventory.
Reason: The quantified material is retained, but its authored name does not identify a sufficiently specific background dataset or defensible proxy; background modeling remains an explicit gap.
Uncertainty: No range defined.
Unit: kg

BCuP-2 atmospheric brazing filler Materialkg

Derivation basis: Calculated from per-operation consumption, operation counts, and manufacturing yield.
REEL derivation: engineering estimate of liquid-cooling manifold and quick-disconnect coupling mass and process inventory from vendor product data and the measured part geometry; no single published inventory covers these parts

The sources for this row are listed below.
Source citations (dataset-level): MGX Accelerated Computing Rack and Trays Specification 1.1
OCP UQDB Specification Revision 1.0
Background data: not modelled
Background dataset: Not applicable: this flow is not quantified in the inventory.
Reason: The quantified material is retained, but its authored name does not identify a sufficiently specific background dataset or defensible proxy; background modeling remains an explicit gap.
Uncertainty: No range defined.
Unit: kg

BNi-6 atmospheric brazing filler Materialkg

Derivation basis: Calculated from per-operation consumption, operation counts, and manufacturing yield.
REEL derivation: engineering estimate of liquid-cooling manifold and quick-disconnect coupling mass and process inventory from vendor product data and the measured part geometry; no single published inventory covers these parts

The sources for this row are listed below.
Source citations (dataset-level): MGX Accelerated Computing Rack and Trays Specification 1.1
OCP UQDB Specification Revision 1.0
Background data: not modelled
Background dataset: Not applicable: this flow is not quantified in the inventory.
Reason: The quantified material is retained, but its authored name does not identify a sufficiently specific background dataset or defensible proxy; background modeling remains an explicit gap.
Uncertainty: No range defined.
Unit: kg

MBF vacuum-brazing filler Materialkg

Derivation basis: REEL derivation: amorphous Ni-Cr-B-Si brazing foil consumption taken as about 0.5 percent of assembly mass as a declared engineering estimate; no retrievable public document was identified for the adopted value

No source is attached to this row.
Source citations: Not stated
Background data: not modelled
Background dataset: Not applicable: this flow is not quantified in the inventory.
Reason: The quantified material is retained, but its authored name does not identify a sufficiently specific background dataset or defensible proxy; background modeling remains an explicit gap.
Uncertainty: No range defined.
Unit: kg

Limitations and unquantified flows (2)

Limits this dataset declares about itself: first any limit stated in its own description, then any limit it declares flow by flow, grouped by channel. Each entry below is the model's own disclosure.

From the dataset description

Coupling vendors do not publish how the body is formed, and a cast or forged body would be brought closer to its finished shape before machining, so the rod route is a declared proxy for the construction rather than a description of it, and it is the route for which a public metal removal rate could be sourced. A reader who needs the forming burden of a near-net-shape body should treat the machining side of this dataset as an upper estimate.

General

The forming of the brass bar this coupling body is machined from is not inventoried. The background database publishes a turning service for brass but no bar, rod or section forming service for it, so drawing the rod is a declared gap here rather than a row. The stainless bar this assembly also buys is unaffected: its rolling is published and is inventoried.

The flows above are this dataset's own records. What follows are the scope rules set once for the whole database in the methodology report, repeated here so every dataset page carries them.

Database-wide boundary policy — applies to every REEL dataset

These boundaries are set once for the whole database, in Chapter 2 of the methodology report, and apply to this dataset wherever they are relevant to it. The excluded flows listed above are specific to this dataset.

Use phase: Product operation is outside the cradle-to-gate scope.
End-of-life treatment: Recycling and disposal are outside the cradle-to-gate scope.
Distribution and retail: The gate is a finished component ready for integration into a higher-level assembly.
Inbound transport of raw materials: Transport of purchased raw materials to the manufacturing facility is already inside the upstream "market for" datasets that users link to a background database, so it is not modelled a second time here. This does not cover freight between REEL production stages, which is modelled where a dataset authors it.
Returnable shipping containers: Where freight between production stages is modelled, the mass moved is the product itself. The shipping container (FOSB, SEMI M31) is returnable capital equipment whose per-trip share is unsourced, so its tare is excluded from the transport effort.
Photomask fabrication: A mask set's embodied burden is amortised across a high-volume production run and is not attributed per wafer. Users assessing low-volume production should add mask fabrication separately; the methodology report gives the basis for the exclusion.
Employee transport, administration and R&D overhead: Employee transportation, facility administration and R&D/pilot-production overhead are outside scope.
Capital goods: Manufacturing equipment, cleanroom construction and facility infrastructure are excluded, on the grounds of absent public data on equipment embodied energy, uncertainty in equipment lifetime and allocation, common practice in electronics LCA, and a focus on the operational inventory. Future versions may include capital goods when sufficient public data becomes available.
Precious metal recovery credits: Scrap recovery credits for precious metals are excluded pending data availability.
Wafer reclaim: Test wafers and scrap are outside the system boundary.

Inside the boundary, linked rather than modelled

Silicon ingot growth and wafer slicing: Inside the cradle-to-gate scope, but treated as upstream material inputs linked to background databases rather than modelled as REEL processes.
Freight between production stages: Where a dataset's product moves between REEL production stages - wafer fabrication to the packaging site, for example - that leg is authored as a transport service and linked to an ecoinvent freight activity. It is measured as a transport effort in tonne-kilometres, not as a mass. Route distances are authored per route class with a stated band; a lower bound of zero is a modelling statement that the two sites can be co-located, not a missing value.

Cut-off criteria

A flow is excluded from a process inventory when it contributes less than 1 % of the total mass of inputs to that unit process, or less than 1 % of its total energy input. The denominator is total process inputs, not product mass. That distinction matters in semiconductor manufacturing, where the input mass of water, chemicals and gases greatly exceeds the product mass, so the threshold removes only genuinely minor flows.

Included regardless of the cut-off

Perfluorocarbons (CF4, C2F6, SF6, NF3) - high GWP, EPA regulated
Heavy metals (Pb, Cd, Hg, Cr(VI)) - RoHS regulated, high toxicity
Volatile organics (photoresist solvents, PGMEA) - air quality
Precious metals (Au, Ag, Pd, Pt) - high embodied impacts
Ozone-depleting substances (legacy CFCs, HCFCs) - Montreal Protocol