For data-center buyers writing immersion-cooling RFQs in mid-2026, the binding constraint is the dielectric fluid, not the tank, and the procurement spec must be anchored to a named chemistry (3M Novec 7000-series with 49-76 °C boiling points and Novec 649 at 49 °C, or Chemours Vertrel/Opteon lines) before any tank or CDU vendor is qualified [S1][S6].
Two-phase fluorinated stacks and single-phase mineral/synthetic-oil baths do not share a supply base, and treating them as interchangeable in an RFQ produces unpriceable bids: the two-phase tier is a chemistry-licensor supply chain with a small set of named vendors, while the single-phase tier is a commodity tank/CDU/pump market with hundreds of Asian contract fabricators and MOQs from US$ 99.9 to US$ 5,000 per pump [S1][S6].
Fluid-Chemistry Tier: Named-First, Compatibility-Second
Two-phase dielectric immersion cooling is gated by hydrofluoroether (HFE) and perfluoroketone (PFK) chemistries from 3M and Chemours, with Shell and ExxonMobil also positioned as fluid licensors for the data-center adjacency [S1]. The fluids typically carry a dielectric strength above 30 kV at a 0.1 in gap, which is the figure the rest of the PCB, plastics, elastomer, and conformal-coating stack is designed against [S1].
Buyers should anchor the RFQ to a named fluid grade and require the tank OEM to publish a materials compatibility list (plastics, elastomers, metals, coatings) against that specific fluid, not a generic "dielectric fluid" claim, because fluid chemistry is the binding constraint on PCB compatibility, materials of construction, and reclamation [S1]. Shell's June 2025 launch of DLC Fluid S3 (a propylene-glycol-based direct liquid cooling fluid rated for freeze protection down to -10 °C, more than 6-year life, and OCP PG25 compliance) shows how fluid suppliers are repositioning to capture the data-center adjacency that was historically held by immersion-only vendors [S7]. A 1 MW immersion deployment can require tens of thousands of litres of qualified dielectric, so the fluid line item should be a separate LOI with volume tier and reclamation terms, not buried in a tank BOM [S7].
Tank and CDU Tier: Where the Commodity Supply Sits
The second tier, covering tank fabricators, CDUs, and skid assemblers, is far less concentrated than the fluid tier and is dominated by Asian contract manufacturers and surface-treatment thermal-control firms that have migrated from plating, anodizing, and rectifier lines into immersion skids [S1]. Haney Electromechanical Equipment Co., Ltd. (Liuyang, Hunan, China, established 2006) is a representative example, listing high-frequency switching rectifiers, industrial water-cooled chillers, immersion heaters, chemical filters, plating tanks, centrifugal pumps, and titanium baskets as a single integrated surface-treatment product set, which is essentially the BOM an immersion CDU/tank integrator needs minus the fluid chemistry [S1].
Made-in-China's B2B index lists 938 immersion-pump manufacturers with 2,814 active SKUs, and representative entries sit in the US$ 99.9-5,000 per piece MOQ band, including Taizhou Kangqiao Electromechanical (US$ 500 per piece, ISO 9001:2015 / ISO 14001 / ISO 45001:2018), Jiangsu South Pump Group (US$ 5,000 per piece), Dongguan Vinsome (US$ 1,000 per set), Shanghai Suoto Pump (US$ 250-999 per piece), and Guangzhou Baiyun Pump (US$ 99-129.9 per piece) [S1]. The same vendor pool typically bids immersion-heater and chiller skids for the secondary side, which means a single-phase RFQ can be consolidated to 2-3 suppliers for the full skid, with the fluid loop spec carried over from the two-phase tier's compatibility matrix where it overlaps [S1]. For adjacent instrumentation on the tank return line, the flow-meter and pressure-transmitter encyclopedia pages cover the dielectric-fluid metering and loop-pressure constraints that apply to immersion tanks. For broader flow-loop instrumentation the flow-meter and pressure-transmitter reference pages give a useful baseline.
Single-Phase vs Two-Phase: Decision Criteria, Side by Side
The two options differ on at least four procurement-critical axes: fluid sourcing model, heat-reuse readiness, secondary-loop complexity, and qualified-vendor count. Two-phase fluorinated stacks are gated by a small set of named fluid licensors (3M, Chemours) with published compatibility lists and reclamation programmes, but require sealed CDUs, condensers, and vapour-handling safety [S1][S6]. Single-phase mineral-oil and synthetic-oil baths are built on commodity tanks, CDUs, and pumps with hundreds of Asian fabricators, MOQs from US$ 99.9 per pump, and a parts base that overlaps with the broader surface-treatment thermal-control industry [S1][S7].
On heat reuse, heated fluid exiting the rack can feed district heating or absorption chillers in European pilot deployments tied to waste-heat recovery mandates, a pattern most visible on two-phase retrofits where the loop already runs at 49-76 °C [S1][S6]. On secondary-side complexity, the two-phase stack needs a vapour condenser and tighter leak management, while single-phase needs only a pumped loop and a plate heat exchanger to the facility water loop [S1][S7]. On standards coverage, no single global standard yet covers immersion cooling end-to-end the way ASHRAE TC 9.9 covers air-side, which is why the named-fluid-and-compatibility-list approach dominates qualified RFQs [S1][S6]. For larger AI-cluster builds with adjacent rack-scale power and motion control, the AI accelerator sourcing guide from China and the related VSD selection piece for wind power are useful procurement cross-references: AI accelerator sourcing from China: 2026 cluster map, vendor lineup, and spec gates and VSD selection for wind power: DFIG, PMSG and full-converter drive-train spec map.
Failure Modes and Constraints Buyers Should Pre-Load
The most common RFQ failure is anchoring on commodity-crypto-mining tank pricing, where high-fluidity dielectric fluids and higher-grade tanks still cost more than the open-air mining containers that dominated the 2017-2021 cycle, and HPC/AI buyers will be unpleasantly surprised if the bid is benchmarked to that pricing band [S1][S8]. A second failure mode is conflating "immersion cooling" with adjacent categories: Made-in-China's index returns a vendor population that is dominated by surface-treatment thermal-control firms (plating, anodizing, rectifier lines) that have pivoted into CDU and heater skids, not fluid chemistry licensors, and the two populations must be qualified separately [S1].
A third constraint is dielectric-fluid metering on the return line, where conventional flow-meter selections sized for water-glycol will read incorrectly on HFE or perfluoroketone fluids because of the differing kinematic viscosity and density profiles, so the metering spec must be re-validated against the named fluid, not the water baseline [S1][S6]. A fourth constraint is the open standards gap: ASHRAE TC 9.9 covers air-side thermal envelopes, but immersion is not yet covered end-to-end, which means the buyer's compatibility matrix is the de facto spec and should be written into the contract, not treated as vendor goodwill [S1][S6].
Procurement Workflow: RFQ, Bid Evaluation, and Award
The first pass is a named-fluid-and-compatibility matrix, locked before any tank vendor is engaged, and the matrix should be issued as a single document so that bid responses can be compared on a fixed compatibility baseline [S1]. The second pass is a two-track bid: Track A for the two-phase fluorinated stack (3M Novec 7000-series or Novec 649, Chemours Vertrel/Opteon) against the licensor's published fluid spec, and Track B for the single-phase oil bath against a separate tank/CDU/pump BOM with its own MOQ tier [S1][S7].
The third pass is fluid LOI: a separate letter of intent on fluid volume, reclamation, and take-back terms, because the fluid line item is large enough (tens of thousands of litres per MW) to move the project financial model on its own [S7]. The fourth pass is secondary-side qualification, where pump, heater, chiller, and filter vendors from the surface-treatment thermal-control industry (Haney Electromechanical, Taizhou Kangqiao, Jiangsu South Pump Group) are scored on plant scale, ISO certifications (ISO 9001:2015 / ISO 14001 / ISO 45001:2018), and MOQ [S1]. The fifth pass is standards and certifications: buyers targeting European chemical-plant or data-center builds should weight third-party sustainability certifications heavily, with industry surveys showing 72% of global IT decision-makers consider these certifications "extremely important" when validating PUE and water-conservation claims [S9]. The market context for the award is a 2024 Grand View Research projection of an 18.7% CAGR from 2024 to 2030 and a valuation above US$ 6.2 billion, with a separate 2026 path projecting a US$ 2.61 billion market by 2032, which gives finance teams a defensible growth narrative for capex approval [S4][S8].
Who This Is For, and Who It Is Not For
Two-phase fluorinated immersion is the right answer for HPC and AI training clusters with 50 kW+ per rack, where the heat-reuse path into district heating or absorption chillers is monetisable and the higher fluid and skid cost can be amortised over a 5-7 year operating window [S1][S6]. Single-phase oil immersion is the right answer for retrofit mining, edge, and brownfield data-center builds where the fluid licence, reclamation, and condenser package of the two-phase stack cannot be installed inside the existing envelope [S1][S7].
It is the wrong answer for buyers who need a turnkey air-cooled drop-in: the BOM, fluid handling, and safety envelope are not interchangeable with hot-aisle/cold-aisle, and the qualification cost is non-trivial even on the commodity single-phase side [S1][S6]. It is also the wrong answer for buyers who cannot pre-commit to a fluid reclamation programme, because the same fluids that define the boiling point and dielectric strength (49-76 °C for 3M Novec 7000-series, 49 °C for Novec 649, above 30 kV dielectric strength at 0.1 in gap) are the constraint on end-of-life handling [S1][S6].
Trackable signals for the next procurement cycle: a published revision or new entrant on the OCP PG25-style open fluid spec that the Shell DLC Fluid S3 launch (June 2025) targeted, and any movement on the open immersion-cooling standard gap relative to ASHRAE TC 9.9 coverage of air-side thermal envelopes [S1][S6][S7].
Spec-level background on the components involved: linear guide.