The springs are categorized into six major types: fluid pipeline connector springs, valve pressure control springs, cold plate hardware locking springs, vibration damping structural springs, energized sealing springs, and cutting-edge shape memory alloy springs. This document marks practical application scenarios, common materials, operating condition parameters, as well as implementation details compliant with NVIDIA GB200/GB300 and OCP standards.
I. Canted Coil Springs (Largest Consumption & Mandatory Component for AI Liquid Cooling)
Application Scenarios
1.UQD/UQDB blind-mate quick disconnect couplings (standard configuration of 252 sets of couplings per cabinet for NVIDIA GB300): Provide radial sealing preload to compensate for thermal expansion & cold contraction and blind-mate alignment deviation (±1~4 mm). Prevent leakage under high pressure of 10~30 bar while balancing plugging service life and resistance against cabinet vibration.
2.GPU cold plate locking rings & metal sealing of cold plate ports: Uniformly compress sealing rings circumferentially to avoid pressure relaxation after long-term high-low temperature cycling.
3.EMI electromagnetic shielding for liquid cooling couplings: Combine sealing performance with grounding conductivity to eliminate electromagnetic interference in high-density computing cabinets.
Main Mass-Production Materials (Genuine Grades)
▫️General working conditions: 316L stainless steel, SUS301; compatible with ethylene glycol and deionized water, operating temperature range: -40℃~120℃
▫️High-pressure / fluorinated liquid immersion cooling: Inconel X-750, Hastelloy C276, MP35N; resistant to fluorinated liquid corrosion and high-temperature creep, with no permanent decline of elastic force under long-term compression
▫️High conductivity requirements: Beryllium Copper C17200
Mandatory Working Parameters (Industry Tested)
Plugging service life ≥ 80,000 cycles; uniform circumferential spring force; leakage rate approaching zero; compliant with OCP liquid cooling coupling specifications
II. Precision Cylindrical Helical Compression Springs (Core Components for Valves & Self-Sealing Couplings)
Application Scenarios
1.Built-in one-way self-sealing poppet springs for UQD quick disconnects: The spring pushes the valve disc closed immediately upon decoupling to achieve zero dripping; the poppet is pushed open for fluid flow during mating. It is the critical part enabling leak-free hot/cold plug maintenance (standard equipment for Stäubli, CPC and domestic BICO UQD).
2.CDU (Coolant Distribution Unit): Reset for overflow relief valves, one-way check valves and flow regulating valves.
3.Reset of manual ball valves on liquid cooling pipelines and locking of cabinet liquid cooling doors.
4.GPU radiator spring assembly: The spring presses the cold plate downward to closely attach to the GPU chip, resisting long-term high-temperature creep and preventing GPU frequency throttling caused by poor thermal contact. These hot compression springs are mandatory for high-power AI GPUs.
Material Classification
1.Conventional water cooling (ethylene glycol): 304/316 stainless steel, SWP-B piano wire; temperature resistance: -40~120℃, complying with GB/T 24588 Stainless Steel Spring Wire standard.
2.High-temperature cold plates (local chip temperature above 120℃): Inconel X-750, SUS631; subjected to closed-end heat treatment to relieve stress relaxation, with compression force attenuation less than 5% throughout long-term operation.
3.High-pressure pump & valve: 50CrVA, 60Si2CrA alloy steel; compliant with GB/T 39519 high-stress hydraulic spring specification, featuring fatigue life of over one million cycles against pressure impact.
III. Wave Springs (Alternative to Ordinary Compression Springs for Narrow Spaces, Exclusive for Compact Cold Plate Structures)
Application Scenarios
1.Sealing preloading for cold plate flanges and pipeline flange end faces: Deliver uniform surface pressure within limited axial thickness, replacing multiple compression springs; top choice for densely stacked cold plate layouts.
2.Seal compensation for liquid cooling pump shaft ends: Wave springs continuously replenish compression force for seals to counteract axial pump wobble during operation.
3.Floating bases of UQDB blind-mate couplings: Multi-turn wave springs enable multi-directional floating to offset cabinet assembly misalignment.
Materials
SUS301, Inconel X-750; resistant to coolant immersion and vibration fatigue, suitable for full temperature range of -55℃~125℃.
IV. Belleville Disc Springs (For Heavy Pressure Impact, Dedicated to High-Pressure Liquid Cooling)
Application Scenarios
1.Mechanical sealing assemblies of high-pressure circulating pumps in CDU: Liquid cooling pressure fluctuates drastically; disc springs feature high bearing capacity with small deflection and maintain stable sealing preload under frequent high-pressure shocks.
2.Flange locking for high-pressure liquid cooling pipelines: Anti-loosening for high-power (80~120kW per cabinet) high-pressure cooling loops.
3.Load-bearing structures of pressure relief safety valves: Rapid rebound to open the valve and release excess pressure when overpressure occurs.
Materials
50CrVA, Inconel 718; fatigue life ≥ 1,000,000 cycles, tolerant to frequent pressure fluctuations in liquid cooling systems.
V. Precision Torsion Springs (Valve Angle Control)
Application Scenarios
1.Liquid cooling proportional flow control valves and manual throttle valves: Precisely control valve rotation opening angle to stabilize loop flow rate.
2.Sliding sleeve unlocking mechanism of pipeline quick couplings: Torsion springs drive automatic rebound and locking of sleeves to prevent accidental disconnection caused by vibration.
Precision Requirements (Mass Production Standards)
Dimensional tolerance ±0.01 mm, torque tolerance ±2%; service life ≥ 100,000 cycles; applicable to narrow pipeline layouts in high-density cabinets. Common materials: SUS304, Beryllium Copper C17200.
VI. V-Springs Embedded in Spring-Energized Seals (Dynamic Seals for Cold Plates & Pump Shafts)
Not independent external springs yet indispensable for liquid cooling sealing: Metal springs are embedded inside modified PTFE sealing rings.
Application Scenarios
Dynamic sealing of inlet/outlet ports on GPU cold plates, shaft sealing for CDU circulating pumps, cable feedthrough & pipeline sealing for immersion liquid cooling tanks. The inner spring continuously tensions PTFE to automatically compensate for wear. Compatible with ethylene glycol and fluorinated liquid, leakage rate ＜0.01mL/min.
Common spring grades: 316L, Hastelloy C276, Inconel X-750.
VII. Vibration Damping & Reset Springs (Pipeline Anti-Vibration for Cabinets)
Application Scenarios
Anti-vibration modules for liquid cooling pipelines of AI servers (Patent No. CN224137695U): Horizontal vibration reset springs paired with dampers offset pipeline shaking induced by water pumps and fans, avoiding leakage resulting from long-term vibration fatigue of couplings. Widely applied on anti-vibration brackets for full-cabinet wiring.
Materials
304 stainless steel, silicon-manganese spring steel.
VIII. SMA Shape Memory Alloy Springs (Mass-Produced Advanced Product, Bulk Adopted by Huawei & Ruijie Liquid Cooling Valves)
Application Scenarios
Passive temperature-controlled flow valves: No sensors required; SMA springs deform with coolant temperature to autonomously adjust valve opening. Spring elongates with rising water temperature to increase flow rate and contracts at low temperature to reduce flow rate. This simplifies liquid cooling temperature control circuits and has achieved commercial application in NVIDIA supporting liquid cooling modules.
Compatible media: ethylene glycol, fluorinated liquid; operating temperature range: -20~100℃, eliminating risks of electronic control failure.
Concise Spring Selection Table by Subsystem
|
AI Liquid Cooling Subsystem |
Core Spring Types |
Core Functions |
Premium Common Materials |
| UQD/UQDB Blind-Mate Couplings |
Canted coil springs, poppet compression springs, torsion springs |
Sealing, self-sealing, locking, floating alignment |
316L, Inconel X-750, C17200 |
| GPU Cold Plates |
Canted coil springs, wave springs, GPU hold-down compression springs |
Sealing preloading, thermal contact compression |
SUS301, Inconel X-750 |
| CDU Pump & Valve Assemblies |
Belleville springs, general compression springs, energized seal springs |
Pressure regulation, non-return, pump sealing |
50CrVA, Hastelloy C276 |
| Cabinet Pipelines |
Damping compression springs, wave springs |
Vibration resistance, flange sealing |
304 Stainless Steel |
| Intelligent Temperature Control Loops |
SMA shape memory springs |
Passive temperature-based flow adjustment |
Nitinol (Nickel-Titanium Alloy) |
Practical Selection Guidelines to Avoid Failures (Non-Negotiable Industry Rules)
1.Ordinary carbon steel springs are prohibited for contact with ethylene glycol/fluorinated liquid. Carbon steel will inevitably rust, clog pipelines, abrade seals and cause leakage.
2.Ordinary stainless steel cannot be used for cold plate springs under long-term high temperature (>100℃); Inconel series is mandatory, otherwise high-temperature creep leads to permanent loss of spring force.
3.Hastelloy C276 and MP35N are prioritized for fluorinated liquid immersion cooling; stainless steel suffers corrosion after long-term immersion.
4.Canted coil springs are required for blind-mate couplings. Standard O-rings cannot compensate thermal expansion, leading to high probability of leakage after long-term operation on GB300 cabinets.
Tiktok
Kwai
REDnote
