02 – Test Parameters per OCP UQD Specification v2.0.0
Source: Open Compute Project – Cooling Environments: Cold Plate Sub-Project, Design Specification Universal Quick Disconnect (UQD) v2.0.0, effective 2026-09-22.
Products: UQD02, UQD04, UQD06, UQD08 (handmate) · UQDB02, UQDB04, UQDB06, UQDB08 (blindmate)
Units: mm unless stated otherwise. bar(g)/psi(g) = gauge pressure.
1. General test requirements
| Parameter |
Value |
Ref |
| Medium (system type) |
Non-flammable single-phase, water/glycol |
§5 |
| Min. samples per test (verification) |
5 (ISO 18869) |
§9 |
| Min. samples per test (cross-verification) |
3 |
§10 |
| Instrument accuracy |
Per ISO 18869:2017 §6.3 |
§9 |
| Helium leak test |
Per ASTM E493 |
§9 |
| QD Property Tests (9.1.x) |
May run in parallel on different samples |
§9 |
| Thermal/Mechanical Tests (9.2.x) |
Run sequentially on the same samples |
§9 |
| Cross-verification |
At least 3 other suppliers; tests 9.1.2, 9.1.3, 9.1.4, 9.1.5 |
§10 |
| Marking |
UQDxx v2 / UQDBxx v2; handmate: colour identification red + blue (minimum) |
§11 |
Test sequence 9.2 (same sample set)
- Helium leak test (optional screening)
- Non-Op temperature cycling (9.2.1)
- Helium leak test (optional screening)
- Op temperature cycling (9.2.2)
- Hydrostatic pressure test (9.2.4)
- Mechanical cycling (9.2.3)
- Hydrostatic pressure test (9.2.4)
| Parameter |
Unit |
02 |
04 |
06 |
08 |
Test |
| Max operating pressure |
bar(g) / psi(g) |
6.89 / 100 |
6.89 / 100 |
6.89 / 100 |
6.89 / 100 |
9.1.1 |
| Min burst pressure |
bar(g) / psi(g) |
20.68 / 300 |
20.68 / 300 |
20.68 / 300 |
20.68 / 300 |
9.1.1 |
| Rated flow |
L/min |
2.27 |
6.44 |
11.36 |
17.79 |
9.1.4, 9.1.5 |
| Rated flow |
GPM |
0.6 |
1.7 |
3.0 |
4.7 |
9.1.4, 9.1.5 |
| Min Cv |
– |
0.30 |
1.1 |
2.2 |
3.6 |
9.1.4 |
| Max Cv |
– |
0.43 |
1.6 |
3.3 |
5.6 |
9.1.4 |
| Max coupling force @ 0 psi ¹ |
N |
55.0 |
65.0 |
90.0 |
135.0 |
9.1.3 |
| Max coupling force @ 0 psi ¹ |
lbf |
12 |
15 |
20 |
30 |
9.1.3 |
| Force/pressure scaling factor |
N/bar |
3.47 |
9.62 |
16.06 |
24.00 |
9.1.3 |
| Force/pressure scaling factor |
lbf/psi |
0.054 |
0.164 |
0.274 |
0.409 |
9.1.3 |
| Min number of coupling cycles |
# |
5000 |
5000 |
5000 |
5000 |
9.2.3 |
| Max fluid loss per cycle |
mL |
0.02 |
0.03 |
0.04 |
0.07 |
9.1.2 |
| Temp. non-operating/shipping |
°C |
−40 … +70 |
← |
← |
← |
9.2.1 |
| Temp. operating |
°C |
+5 … +65 |
← |
← |
← |
9.2.2 |
| Storage life (from T0 = date of manufacture) |
years |
5 |
5 |
5 |
5 |
– |
| Service life in operation (after storage) |
years |
10 |
10 |
10 |
10 |
– |
¹ Applies to UQDB only (valve force). For handmate UQD the latch mechanism is expected to give a marginally higher force.
Pressure drop equation: ΔP(Q) = A·Q² + B·Q (ΔP in psi, Q in L/min). Min/max for A, B are not yet defined in v2.0.0.
Max flow (recommendation): volume flow corresponding to 5 m/s through the smallest cross-section area – contact the QD supplier.
2.1 Calculated max coupling forces at test pressure (UQDB)
F_max = F(0 psi) + p · scaling factor
| Size |
0 bar(g) |
2.76 bar(g) |
6.89 bar(g) |
| UQDB02 |
55.0 N |
64.6 N |
78.9 N |
| UQDB04 |
65.0 N |
91.6 N |
131.3 N |
| UQDB06 |
90.0 N |
134.3 N |
200.7 N |
| UQDB08 |
135.0 N |
201.2 N |
300.4 N |
2.2 Calculated flows for the tests
| Size |
25 % (L/min) |
100 % (L/min) |
150 % (L/min) |
200 % – Seal washout (L/min) |
200 % (GPM) |
| 02 |
0.57 |
2.27 |
3.41 |
4.54 |
1.2 |
| 04 |
1.61 |
6.44 |
9.66 |
12.88 |
3.4 |
| 06 |
2.84 |
11.36 |
17.04 |
22.72 |
6.0 |
| 08 |
4.45 |
17.79 |
26.69 |
35.58 |
9.4 |
3. Test parameters per test
9.1.1 Burst Pressure
| Parameter |
Value |
| Object |
Plug, socket and mated coupling |
| Position |
Fully mated (UQD only) and unmated (all plugs/sockets) |
| Test pressure |
To failure, or 3 × min. proof pressure – whichever is lower |
| Pressure rise rate |
Per ISO 18869 |
| Acceptance |
Burst pressure > 20.68 bar(g) / 300 psi(g) |
| Result |
P/F per sample (1–5) for Plug / Socket / Mated |
⚠️ "Minimum proof pressure" is not defined in the specification – determine the value (e.g. from ISO 18869 or customer requirement) before the test.
9.1.2 Fluid Loss
| Parameter |
Value |
| Method |
ISO 18869 §12 |
| Test medium |
Water |
| Acceptance (mL/cycle) |
02: ≤ 0.02 · 04: ≤ 0.03 · 06: ≤ 0.04 · 08: ≤ 0.07 |
| Record |
Liquid level before/after (mL), number of couplings, loss per cycle, mean over samples |
9.1.3 Force to Connect
| Parameter |
Value |
| Method |
ISO 18869 §7 |
| Repetitions |
5 per sample; max force per test, the mean of all maxima over all samples is reported |
| Temperature |
Room temperature |
| Test pressure |
0 / 2.76 / 6.89 bar(g) (0 / 40 / 100 psi(g)), pressure on both plug and socket |
| Medium |
Air or water, pressurized |
| Connection speed |
40 ± 10 mm/s |
| Alignment |
Fully radially and angularly aligned (unless stated otherwise) |
| Lubrication |
No extra lubrication or alignment beyond normal use |
| Specific to UQDB |
Test at max radial misalignment (SA = 1.00 +0.30/−0.00 mm), reset after each cycle |
| Acceptance |
See table 2.1 (UQDB) |
9.1.4 Pressure Drop
| Parameter |
Value |
| Method |
ISO 18869 §13 (with deviations below) |
| Temperature |
25 ± 5 °C |
| Medium |
Water |
| Flows |
At least 6 flows between 25 % and 150 % of rated flow, incl. 100 % |
| Flow direction |
Both: S→P and P→S |
| Samples |
n = 5 minimum, mean per direction |
| UQDB & Hybrid |
Fully mated, hard-stop |
| Tare (§13.3) |
Remove the coupling, connect hoses with a tare adapter; same hose/fittings between the pressure taps in test and tare |
| Net pressure drop (§13.5) |
Pressure drop test − pressure drop tare |
| Report |
Curve fit ΔP = A·Q² + B·Q (psi, L/min), ΔP at 100 % and 150 %, A, B, min Cv |
| Cv formula |
Cv = Q · √(SG / ΔP), Q in GPM, ΔP in psi |
| Acceptance |
Cv at rated flow within [Min Cv, Max Cv] per Table 6 |
Straight pipe lengths (ISO 18869 Fig. 13), minimum:
| Section | Length |
|---|---|
| L1 | 10 × inside diameter |
| L2 | 5 × inside diameter |
| L3 | Length of the coupling incl. end fittings |
| L4 | 10 × inside diameter |
| L5 | 5 × inside diameter |
Hose/pipe ID for the test (= hosebarb size in Table 5, ±10 %):
| Size | Nominal ID | ID range (mm) | L1/L4 min (mm) | L2/L5 min (mm) |
|---|---|---|---|---|
| 02 | 1/4" = 6.35 mm | 5.72 – 6.99 | 63.5 | 31.8 |
| 04 | 3/8" = 9.525 mm | 8.57 – 10.48 | 95.3 | 47.6 |
| 06 | 1/2" = 12.70 mm | 11.43 – 13.97 | 127.0 | 63.5 |
| 08 | 5/8" = 15.875 mm | 14.29 – 17.46 | 158.8 | 79.4 |
Adapters ISO 11926-3 male stud → hosebarb (example in spec):
| End | ID (mm) | Tol. | Length (mm) | Tol. |
|---|---|---|---|---|
| 11926 7/16 | 4.4 | ±0.08 | 9.1 | ±0.2 |
| 1/4 HB | 4.4 | ±0.08 | 20.5 | REF |
| 11926 9/16 | 7.5 | ±0.1 | 10 | ±0.2 |
| 3/8 HB | 7.5 | ±0.1 | 24.1 | REF |
| 11926 3/4 | 10 | ±0.1 | 11.1 | ±0.2 |
| 1/2 HB | 10 | ±0.1 | 28 | REF |
| 11926 7/8 | 12.5 | ±0.1 | 12.7 | ±0.2 |
| 5/8 HB | 12.5 | ±0.1 | 38 | REF |
| 11926 1-1/16 | 15.5 | ±0.12 | 15.1 | ±0.2 |
| 3/4 HB | 15.5 | ±0.12 | 38 | REF |
Common: stud length 9.5 mm [0.38"], Ø per SAE J1926-3 / ISO 11926-3.
Tare adapter (straight, thread 1 – thread 2):
| Coupling | Thread 1 | Diameter D (mm) | Length L (mm) | Thread 2 | Length L2 (mm) |
|---|---|---|---|---|---|
| UQDB02/UQDH02 | 7/16-20 | 9.88 ± 0.15 | 96 ± 5 | 9/16-18 | 14.5 ± 0.5 |
| UQDB04/UQDH04 | 9/16-18 | 12.92 ± 0.17 | 112 ± 5 | 3/4-16 | 16 ± 0.5 |
| UQDB06/UQDH06 | 3/4-16 | 17.5 ± 0.18 | 124 ± 5 | 7/8-14 | 18 ± 0.5 |
| UQDB08/UQDH08 | 7/8-14 | 20.48 ± 0.21 | 139 ± 5 | 1-1/16-12 | 20.5 ± 0.5 |
Threads per SAE J1926-1 / ISO 11926-1.
9.1.5 Seal Washout (closed loop)
| Parameter |
Value |
| Number of cycles |
20 per flow direction (P→S and S→P) |
| Connection speed |
40 ± 10 mm/s |
| Flow |
2 × rated flow (see table 2.2) |
| Temperature |
60 °C |
| Pressure |
6.9 bar(g) / 100 psi(g) operating (excl. transient spike) |
| Max pressure spike at disconnect |
≤ 30 psi (2.07 bar) above pressure before disconnect |
| Medium |
Water or PG25 |
| Latch mechanism (handmate) |
May be removed/bypassed |
| Pipe length L (WHA ↔ QD) |
< 5 × ID |
| Acceptance |
No leakage, no seal washout |
Set-up: Accumulator (air, valve A), circulation pump with bypass (valve B), pressure gauge C (upstream) and D (downstream), WHA on both sides of the QD, flow meter (LPM).
Procedure: Set the flow with the coupling mated → stop the pump, disconnect → start the pump → pressurize via A to max operating pressure at C → stop the pump → connect → check flow → run cycles → change flow direction and repeat.
9.2.1 Non-Operational (Shipping) Temperature Cycling
| Parameter |
Value |
| Position |
Fully mated (UQD/UQDB) and unmated (plug/socket); mated: connect the counterpart and plug the end |
| Set-up |
QD in an all-metal enclosure, total volume ≤ 0.5 L (as small as possible) |
| Temperature |
−40 °C for 72 h, +70 °C for 72 h, back to room temp. |
| Transition rate |
5 – 10 °C/min |
| Medium |
Air, 28 – 30 psi(g) (≈ 1.93 – 2.07 bar(g)) |
| Pressurization / reading |
At room temperature before and after |
| Specific to UQDB |
Fully mated, hard-stop |
| Helium leak test |
Optional before and after (ASTM E493) |
| Acceptance |
Pressure drop per QD ≤ 1 % of the pressure at T0 (at 30 psi: ≤ 0.3 psi/QD) |
Example: 30 → 28 psi with 10 QDs = 0.2 psi/QD < 0.3 psi → pass.
9.2.2 Operational Temperature Cycling
| Parameter |
Value |
| Position |
Mated at nominal engagement (UQD/UQDB/Hybrid) and unmated (plug/socket) – two populations or the same in series |
| Temperature |
+5 °C for 72 h, +65 °C for 72 h, back to room temp. |
| Transition rate |
5 – 10 °C/min |
| Pressure |
6.9 bar(g) / 100 psi(g) at test temperature |
| Medium |
Water or PG25 (compensate for evaporation) |
| Acceptance |
No visible leakage; followed by hydrostatic test 9.2.4 |
9.2.3 Mechanical Cycling
| Parameter |
Value |
| Number of cycles |
5000 |
| Connection speed |
40 ± 10 mm/s |
| Temperature |
Normal lab environment |
| Pressure |
2.75 bar(g) / 40 psi(g) |
| Medium |
Water or PG25 |
| UQD |
Latch engaged every cycle; on-axis |
| Hybrid |
On-axis; floating mechanism not needed but compliance must exist in the fixture |
| UQDB |
Cycled with SA offset (1.00 mm radial) |
| Acceptance |
No visible leakage; followed by hydrostatic test 9.2.4 |
9.2.4 Hydrostatic Pressure Test
| Parameter |
Value |
| Object |
Plug, socket and/or mated coupling per the preceding test |
| Preparation |
Bleed the system |
| Pressure |
6.9 bar(g) / 100 psi(g) |
| Hold time |
≥ 3 min |
| Unmated |
Pressure in the direction that tends to close the valve |
| Mated |
Ensure 6.9 bar(g) internally; connect the counterpart and plug the end |
| Temperature |
Normal lab environment |
| Medium |
Water or PG25 |
| Acceptance |
No visible leakage |
| Size |
Hybrid (UQD plug + UQDB socket) MIN / NOM / MAX |
UQDB MIN / NOM / MAX |
| 02 |
35.85 / 36.30 / 36.75 |
35.6 / 36.1 / 36.6 |
| 04 |
43.6 / 44.1 / 44.5 |
43.8 / 44.3 / 44.8 |
| 06 |
47.1 / 47.6 / 48.0 |
47.1 / 47.6 / 48.1 |
| 08 |
51.1 / 51.6 / 52.0 |
50.9 / 51.4 / 51.9 |
Hard-stop: UQDB = flat faces against each other; Hybrid = the socket cone against the tangent diameter on the plug flange. Handmate: socket length is the max keep-in (DD), the plug position varies with the latch mechanism.
5. Dimensions
5.1 UQD Socket (Table 1)
| Dim |
Tol. |
UQD02 |
UQD04 |
UQD06 |
UQD08 |
| A |
MIN |
11.25 |
15.65 |
18.85 |
22.05 |
| B (sealing surface) |
±0.025 |
6.71 |
11.15 |
14.38 |
17.56 |
| C |
±0.025 / [MIN, MAX] |
3.63 |
7.14 |
[9.45, 9.65] |
[10.73, 11.07] |
| E |
MIN – MAX |
12.8 – 13.7 |
16.6 – 18.1 |
17.3 – 18.8 |
18.5 – 20.0 |
| F |
±0.10 |
3.3 |
4.7 |
5.4 |
6.6 |
| S max (valve stroke) |
REF |
8.0 |
11.7 |
14.5 |
17.3 |
| CC (Ø keep-in) |
MAX |
21.0 |
26.0 |
30.0 |
37.0 |
| DD (length keep-in) |
MAX |
50.0 |
60.0 |
65.0 |
75.0 |
| Entry chamfer angle |
|
35° ± 0.5° |
← |
← |
← |
Note: Sealing surface B is machined to ≤ 32 Ra. Asymmetric latch mechanisms may exceed CC.
5.2 UQD Plug (Table 2)
| Dim |
Tol. |
UQD02 |
UQD04 |
UQD06 |
UQD08 |
| G |
±0.025 |
11.0 |
15.4 |
18.6 |
21.8 |
| H (sealing surface) |
±0.025 |
6.65 |
11.07 |
14.30 |
17.48 |
| J |
MIN |
21.0 |
29.0 |
32.5 |
36.5 |
| L |
±0.025 |
3.73 |
7.24 |
9.75 |
11.17 |
| M |
MIN – MAX |
2.4 – 3.0 |
3.0 – 3.8 |
3.5 – 4.8 |
3.8 – 5.8 |
| N |
±0.1 |
15.5 |
21.5 |
25.0 |
29.0 |
| P |
±0.06 |
14.8 |
20.7 |
24.2 |
28.2 |
| Q |
±0.3 |
19.4 |
26.5 |
30.0 |
34.0 |
| R |
MAX |
6.8 |
11.2 |
14.2 |
17.4 |
| AA (TSC) |
±0.10 |
14.10 |
19.20 |
22.67 |
26.69 |
| BB |
±0.10 |
27.0 |
35.4 |
38.9 |
42.9 |
| GG |
MAX |
16.5 |
19.8 |
25.5 |
30.0 |
| HH |
±0.10 |
0.50 |
0.85 |
0.85 |
0.85 |
| JJ |
±1.0° |
15° |
10° |
10° |
10° |
Detail A (latch surfaces): 20° ± 0.5°, 45° ± 0.5°, 35° ± 0.5°, R1.0 ± 0.10, R0.2 ± 0.10, R0.2–0.3.
Detail B (tip): R0.3 min or equivalent chamfer, 2× R0.4 ± 0.10. Sealing surface H ≤ 32 Ra.
5.3 UQDB Socket (Table 3)
| Dim |
Tol. |
UQDB02 |
UQDB04 |
UQDB06 |
UQDB08 |
| B (sealing surface) |
±0.025 |
6.71 |
11.15 |
14.38 |
17.56 |
| C |
±0.025 / [MIN, MAX] |
3.63 |
7.14 |
[9.45, 9.65] |
[10.73, 11.07] |
| T (TSC) |
REF |
4.81 |
5.20 |
4.95 |
4.76 |
| U (TSC) |
±0.1 |
11.2 |
16.0 |
19.0 |
22.0 |
| V |
±0.3 |
7.11 |
8.90 |
9.35 |
10.36 |
| FF |
±0.1 |
23.62 |
28.50 |
31.75 |
35.56 |
| KK |
MIN |
15.5 |
19.5 |
24.5 |
26.5 |
| MM |
±0.15 |
18.0 |
22.9 |
26.1 |
29.9 |
| NN |
±0.2 |
15.2 |
20.0 |
25.2 |
27.5 |
| PP |
MIN |
5.3 |
6.7 |
8.3 |
9.0 |
| QQ |
±0.15 |
17.5 |
22.3 |
27.5 |
29.8 |
| RR |
±0.15 |
17.5 |
22.3 |
27.5 |
33.0 |
| Cone angle |
|
25.0° ± 0.5° |
← |
← |
← |
Detail C: 2.65 ± 0.1, (1.15), 4× R0.2 ± 0.1. Other: R0.2 min, R0.2 ± 0.10, 1.5 min. Sealing surface ≤ 32 Ra.
5.4 UQDB Plug (Table 4)
| Dim |
Tol. |
UQDB02 |
UQDB04 |
UQDB06 |
UQDB08 |
| H (sealing surface) |
±0.025 |
6.65 |
11.07 |
14.30 |
17.48 |
| K |
±0.3 |
11.0 |
16.1 |
19.6 |
23.6 |
| L |
±0.025 |
3.73 |
7.24 |
9.75 |
11.17 |
| M |
MIN – MAX |
2.4 – 3.0 |
3.0 – 3.8 |
3.5 – 4.8 |
3.8 – 5.8 |
| X |
±0.1 |
27.0 |
35.4 |
38.9 |
42.9 |
| Y |
±0.3 |
14.50 |
19.60 |
23.10 |
27.10 |
| W |
±0.15 |
21.4 |
25.4 |
28.4 |
31.4 |
| SA (radial self-alignment) |
+0.30 / −0.00 |
1.00 |
1.00 |
1.00 |
1.00 |
| HH |
±0.10 |
0.50 |
0.85 |
0.85 |
0.85 |
| JJ |
±1.0° |
15° |
10° |
10° |
10° |
Cone angle 150° min. Keep-in zone bounded by Y, K and the min angle.
6. Terminations (Table 5)
Plug – UQD & UQDB (stud end ISO 11926-3)
| Size |
Stud |
Thread |
Hex UQD |
Hex UQDB |
Torque |
| 02 |
ORB-04 |
7/16-20 UNF-2A |
14 mm |
19 mm |
9 Nm |
| 04 |
ORB-06 |
9/16-18 UNF-2A |
17 mm |
24 mm |
15 Nm |
| 06 |
ORB-08 |
3/4-16 UNF-2A |
22 mm |
27 mm |
25 Nm |
| 08 |
ORB-10 |
7/8-14 UNF-2A |
27 mm |
30 mm |
30 Nm |
Socket – UQDB (stud end ISO 11926-3)
| Size |
Stud |
Thread |
Hex |
Torque |
| 02 |
ORB-06 |
9/16-18 UNF-2A |
16 mm |
15 Nm |
| 04 |
ORB-08 |
3/4-16 UNF-2A |
20 mm |
25 Nm |
| 06 |
ORB-10 |
7/8-14 UNF-2A |
25 mm |
30 Nm |
| 08 |
ORB-12 |
1-1/16-12 UN-2A |
27 mm |
48 Nm |
Socket – UQD (hosebarb, push-lock, reinforced EPDM hose)
| Size |
02 |
04 |
06 |
08 |
| Hosebarb |
1/4" |
3/8" |
1/2" |
5/8" |
Receiving port: ISO 11926-1. Torques are recommended (depend on material, lubrication etc.).
7. Materials (Table 8)
| Area |
Material |
| UQD/UQDB plug – outer tip/shaft |
SUS 303 / 304 / 304L / 316 / 316L |
| UQD/UQDB cone and guide area |
SUS 303 / 304 / 304L / 316 / 316L |
Wetted materials shall be compatible with the OCP guidelines for water-based and PG-based coolants respectively.
8. Visual inspection (Appendix 15.2, recommendation)
| Attribute |
Acceptance |
Zone |
| Surface defects |
≤ 0.3 mm² |
1, 2, 4a, 4b, 7 |
| Surface defects |
≤ 1.0 mm² |
3, 4, 5, 6 |
| Machining marks |
OK within Ra requirement |
All |
| Chips/burrs |
None (loose or attached) |
All |
| Foreign material/corrosion |
None (passivation yellowing OK) |
All |
| Thread profile |
Check with thread gauge or mating port |
1, 7 |
Inspection: 360° rotation, magnification recommended, illumination ~700–1200 lux, TAPPI/ANSI T 564 for size assessment, loose particles may be blown off with filtered compressed air.
9. Open points / ambiguities in the specification
- Burst 9.1.1: "minimum proof pressure" has no definition – needs to be determined.
- Hybrid configuration (UQD plug + UQDB socket) is included in 9.2.2/9.2.3 and the mated lengths – decide whether it is to be tested in addition to the UQD and UQDB pairs.
- Pressure drop coefficients A, B: min/max not defined in v2.0.0 – reporting only.
- Force/pressure scaling factor: N/bar and lbf/psi in Table 6 do not agree for 04–08 (see 04-Backlog ER-001). Table 2.1 uses N/bar.
- Test template 15.3.3 wrongly labels operational cycling "Subtest 9.2.1" – should be 9.2.2.
- Coupling force requirement in Table 6 formally applies to UQDB only; no limit exists for UQD.