| Pipe Material | Aluminum alloy, stainless steel, or engineered thermoplastic such as PA12 and multilayer barrier tubing. | Material is selected according to coolant compatibility, operating temperature, pressure, weight, electrical insulation, and corrosion requirements. | Material certificates, chemical composition records, dimensional inspection, and coolant-compatibility testing should be available. |
| Tube Forming | Round tubes are commonly formed into routed paths that follow the battery pack, module, or cold plate layout. | Common processes include extrusion, precision cutting, CNC or rotary bending, hydroforming, and dedicated forming dies. | Profile dimensions, bend radius, spring-back, flatness, and alignment are checked against approved drawings. |
| Typical Size Range | Many application-specific designs use small-diameter tubing or flattened channels; exact dimensions are determined by flow, packaging, and heat-load calculations. | Manufacturers normally produce samples from customer CAD data before creating production tooling. | The final design should be validated for pressure drop, coolant velocity, minimum bend radius, and clearance from high-voltage components. |
| Connector and End Fittings | Aluminum, stainless steel, brass, or reinforced polymer fittings may be used with O-rings, quick connectors, or hose interfaces. | Ends may be expanded, flared, swaged, welded, brazed, crimped, or assembled with sealing components. | Insertion depth, retention force, torque, sealing surface condition, and connector orientation are inspected. |
| Joining Technology | The joining process depends on the material and may include TIG welding, laser welding, brazing, crimping, or mechanical coupling. | Automated fixtures and controlled welding or brazing parameters are used to maintain repeatable joint quality. | Visual inspection, dimensional checks, joint-strength testing, and leak testing are used to verify the connection. |
| Surface Treatment | Possible treatments include cleaning, degreasing, anodizing, conversion coating, passivation, or protective coating. | The surface is treated according to corrosion exposure, coolant chemistry, electrical isolation, and assembly requirements. | Coating coverage, appearance, adhesion, corrosion resistance, and cleanliness are evaluated. |
| Cleanliness Control | Internal passages must be free from metal chips, dust, oil, moisture, and welding residue. | Parts are commonly flushed, dried with filtered air, capped, and packed in clean protective materials. | Particle extraction, visual inspection, drying verification, and sealed-packaging checks support cleanliness control. |
| Leak Testing | Air-decay, pressure-decay, helium, or immersion testing may be selected according to the required leak limit. | Every finished assembly can be tested using calibrated equipment after forming and joining operations. | Acceptance limits must be defined on the product specification; test pressure, hold time, calibration status, and results should be traceable. |
| Thermal-Hydraulic Validation | Key factors include coolant flow rate, pressure drop, heat transfer, temperature uniformity, and resistance to vibration. | Prototype assemblies are evaluated on flow benches and may be tested with representative battery modules or cold plates. | Test results should meet the thermal-management design target across the specified temperature and flow conditions. |
| Automotive Reliability Testing | Typical evaluations include thermal cycling, vibration, pressure cycling, burst strength, corrosion exposure, and coolant aging. | Testing is performed according to customer specifications and applicable automotive validation plans. | Requirements should be agreed before mass production and documented in a validation report. |
| Production Traceability | Traceability may cover raw-material batch, forming lot, welding parameters, operator or equipment, inspection results, and shipment date. | Chinese factories commonly use barcode, QR-code, or enterprise manufacturing systems to connect process records with finished parts. | A supplier should provide a documented quality system, corrective-action process, and retention period for inspection records. |
| Applicable Management Standards | ISO 9001 is widely used for quality management; automotive programs may require IATF 16949 and customer-specific requirements. | Qualified manufacturers integrate incoming inspection, process control, final inspection, nonconformance handling, and continuous improvement. | Certification validity, scope, audit status, and product-specific capability should be verified independently. |