The call came in on a Tuesday afternoon. A mechanical contractor managing the HVAC buildout for a new 40MW AI data center in Texas had a problem — not with the chillers, not with the cooling towers, and not with the CDUs. The leak was in a flex connector. A standard rubber expansion joint that had been spec’d off a generic catalog, installed under pressure during a compressed schedule, and now failing at a weld flare fitting. The system had been live for eleven weeks.
That story is more common than most people in this industry want to admit. And as liquid cooling becomes the standard for AI infrastructure — not the exception — the stakes around flexible connectors and thermal piping components are rising fast.
The Market Numbers Are Not Subtle
The data center liquid cooling market was valued at $4.8 billion in 2025 and is expected to grow at an 18.2% CAGR through 2035, according to Global Market Insights. A separate analysis puts the market at $5.5 billion in 2025, tracking toward $15.8 billion by 2030. Liquid cooling connectors specifically — the quick-disconnects, braided hoses, and flexible couplings that make a CDU loop possible — are projected to grow from roughly $203 million in 2025 at a 9.8% CAGR through 2033.
The driver isn’t a mystery. NVIDIA’s H200 GPU carries a 700W TDP. The GB200 NVL72 rack system can exceed 100kW of thermal load. Air cooling simply cannot move that kind of heat efficiently. IDTechEx estimates approximately $55,000 in cooling components are required per GB200 server rack — and the flexible piping connecting those racks to the CDU is not where any engineer wants to find the weak link.
At the same time, the broader data center cooling market — encompassing chillers, CRAC units, HVAC systems, and all associated piping infrastructure — hit $26.3 billion in 2025 and is projected to reach $128.3 billion by 2033, a 22.3% CAGR. The HVAC segment alone accounted for 76% of the cooling solutions market in 2025. Every one of those HVAC installations depends on expansion joints, flexible connectors, pump connectors, and vibration isolators doing their job without failure.
Who Is Actually Buying These Components — and Why It Matters
If you’re reading this, you’re likely one of a few types of buyers. You might be a mechanical or MEP contractor working on a hyperscaler build-out or a colo expansion. You might be a data center facilities manager responsible for keeping a 20MW or 40MW campus running at five-nines uptime. You could be a design engineer at an AEC firm speccing piping systems for a new liquid-cooled AI cluster. Or you’re a procurement professional at a colocation operator trying to source fast, spec compliantly, and avoid the kind of part substitution that ends with a leak in month three.
All of these buyers share the same core problem: the components that connect the cooling infrastructure together — flexible hose assemblies, rubber and metal expansion joints, pump connectors, pipe guides and anchors — are often treated as commodity line items. They are not.
An AI data center chiller plant running glycol-water coolant at elevated pressures through direct-to-chip loops is not the same application as a commercial office HVAC system. The thermal cycling is more aggressive. The operating pressures are higher. The penalty for unplanned downtime — with GPU clusters that cost tens of millions of dollars sitting idle — is measured in hours of lost compute revenue, SLA penalties, and reputational damage to the operator.
What Liquid Cooling Actually Demands from the Piping System
The shift from air-cooled to liquid-cooled architectures is reshaping what the piping infrastructure must do. In a direct-to-chip or rear-door heat exchanger installation, coolant is flowing continuously through CDUs, manifolds, cold plates, and the facility chilled water plant. That loop includes dozens — sometimes hundreds — of flexible connection points.
Each one must handle vibration isolation from pumps and compressors, thermal expansion and contraction as system temperatures cycle, pressure surges during startup and shutdown, and potential misalignment between equipment skids and fixed piping. A rubber expansion joint that performs adequately in a low-pressure office HVAC circuit may delaminate, collapse under vacuum, or fail at the bead ring in a data center loop running at higher differential pressures or with aggressive glycol concentrations.
Metal expansion joints — particularly stainless steel bellows assemblies — have become the preferred choice in many high-spec liquid cooling installations because of their resistance to permeation, their ability to handle higher working pressures, and their compatibility with the chemical inhibitors used in coolant formulations. But metal expansion joints also require proper anchor and pipe guide placement to function correctly. Undersupported bellows will absorb forces they were never designed to handle, and fatigue failure follows.
The 2025 cooling buildout cycle has revealed a gap: the CDU vendors, the chiller OEMs, and the cooling loop integrators have matured rapidly, but the ancillary piping components — the flex connectors, the pump isolation joints, the anchors and guides — are often still being sourced as an afterthought, from whoever can ship fastest at the lowest price.
The Five Component Categories You Need to Get Right
For any MEP contractor, facilities engineer, or procurement lead working on an AI data center cooling system, the following component categories deserve specification-level attention — not catalog shopping.
Pump Connectors and Vibration Isolation Joints. Every chilled water pump and CDU pump introduces vibration into the system. Without proper flexible pump connectors, that vibration transmits into piping supports, causes fatigue in welded joints, and generates noise that violates data center acoustic requirements. High-pressure-rated pump connectors in stainless steel or EPDM are the right call for liquid cooling loops, not generic rubber couplings pulled from distribution stock.
Rubber and Metal Expansion Joints at Thermal Interfaces. Direct-to-chip loops experience significant temperature swings — from ambient during shutdown to operating temperatures well above 30°C during full GPU load. That thermal delta drives linear expansion in piping that must be absorbed somewhere. Properly sized expansion joints, placed at the right intervals with correctly specified anchor and guide systems, are the engineering solution. Skipping them, or under-specifying them, means that force gets transmitted to equipment flanges, structural supports, or the CDU connection points themselves.
Flexible Metal Hose Assemblies for Equipment Connections. Anywhere a CDU, chiller, or pump skid connects to the facility piping, there will be some degree of misalignment, vibration, and thermal movement. Flexible stainless steel hose assemblies — braided, with appropriate end fittings for the application — bridge that gap. The braid rating matters. The end fitting material matters. The bend radius in the installed position matters. These are engineered components, not plumbing supplies.
Pipe Anchors and Guides. This is the part that most purchasing teams don’t think about until something goes wrong. Expansion joints only function as designed when the piping system is properly constrained. Anchors hold fixed points. Guides allow controlled axial movement. Without them, the entire pipe guide and anchor system fails as a system, and expansion joints absorb forces in directions they weren’t designed to handle.
Seismic and Structural Flexible Connectors. Data centers in seismic zones — which includes a significant portion of the western U.S. and expanding markets in the Pacific Rim — require flexible connections that can accommodate seismic movement without system failure. This is not optional in high-risk zones, and the specification requirements are exacting.
The Schedule Problem — and the One Thing That Solves It
AI data center construction timelines have compressed dramatically. Hyperscaler campuses that once took 24 to 36 months to deliver are being pushed to 18 months or less. That schedule pressure flows directly to the mechanical subcontractors and procurement teams who need flexible connectors and piping components on-site, to spec, fast.
This is where most national distribution channels fall short. They can ship generic catalog items quickly. They cannot rapidly deliver custom-fabricated metal expansion joints, application-specific rubber flex connectors, or non-standard hose assemblies with engineered end fittings — not without long lead times, not without multiple qualification rounds, and not without the kind of technical support that helps an engineer select the right product for the operating conditions.
What the AI data center build-out actually needs is a manufacturer with deep inventory in standard configurations, in-house custom fabrication for non-standard requirements, and a technical sales team that can turn around a quote on a complex assembly the same day. That combination — inventory depth plus custom fab plus fast technical response — is the actual value proposition that moves projects forward.
Facilities that get this right spec their flexible components early, engage a knowledgeable supplier during design, and avoid the emergency phone call at week eleven.
What to Look for in a Supplier
Not all flexible connector manufacturers are equipped for the demands of mission-critical cooling infrastructure. When evaluating a supplier for an AI data center project, the questions worth asking are: Do they fabricate in-house or broker out? What is their typical lead time on custom metal expansion joints? Can they provide ASME-compliant documentation? Do they carry stainless steel, PTFE, and rubber product lines, or are they a single-material shop? Can their sales engineers review your application and recommend the correct product — or will they just quote what you ask for?
Experience across multiple demanding applications matters here. A manufacturer that has supplied thermal expansion joints for power generation, seismic connectors for marine applications, and vibration isolators for industrial HVAC systems has already solved the hard problems. They understand misalignment tolerances, pressure ratings under cycling loads, and the material compatibility questions that a data center-specific application will eventually raise.
Engineered Flexible Products has been working in exactly these applications since 1999 — across power generation, HVAC, cryogenic, petrochemical, maritime, and industrial markets. The same engineering principles that govern a metal expansion joint on a ship’s exhaust system govern a bellows assembly in a chilled water plant. The materials change. The physics does not.
If your next data center cooling project involves flexible connectors, expansion joints, pump isolation assemblies, or pipe anchor systems, and you want a manufacturer who can move at the speed of your build — reach out for a quote. Same-day response. In-house fabrication. Technical support from people who have been in this industry for decades.