China's Survey on Imported Medical CT Bulb Tubes Will Affect Tungsten Materials Application?

On April 4, 2025, China’s Ministry of Commerce (MOFCOM) announced the initiation of an industrial competitiveness investigation into imported medical CT ball tube, alongside a separate anti-dumping investigation targeting specific imports from the United States and India. This dual approach reflects China’s strategic response to challenges faced by its domestic medical CT tube industry, which is still in a developmental phase and grappling with competitive pressures from imports.

According to Xinhua News, the applicant—representing the domestic industry—provided preliminary evidence indicating that China’s medical CT tube sector, despite a late start, has been significantly impacted by imported products. From 2022 to 2024, imports of related products from the U.S. and India reportedly increased by a cumulative 13%, while their prices continued to decline. This has exerted downward pressure on domestic sales prices, leading to operational difficulties and losses for Chinese producers. The applicant requested MOFCOM to investigate the effects of these imports on the domestic industry and its competitiveness.

A MOFCOM Trade Remedy and Investigation Bureau official elaborated that, after reviewing the application under Chinese laws and World Trade Organization (WTO) rules, the agency found sufficient grounds to launch an anti-dumping probe. The industrial competitiveness investigation, meanwhile, aims to broadly assess the impact of imports on the domestic sector, independent of specific countries unless tied to the anti-dumping scope.

Investigation Details

(1) Products Under Investigation

English Name: X-Ray Tube Assemblies and Tube (Insert) Thereof for Medical CT Device; abbreviated as Medical CT Tubes.

Description: The investigation covers imported X-ray CT tubes and their inserts designed for CT scanners with 16 or more detector rows. This includes standalone inserts, semi-finished tubes, and complete tube assemblies.

Physical Characteristics: Medical CT tubes are the X-ray source in CT equipment, typically comprising an insert (core component), sleeve, cooling system, and electrical system. The insert generates X-rays by heating a cathode filament to emit electrons, which strike an anode target under an electric field. The sleeve secures the insert, houses the electrical system, connects to the cooling system, encapsulates coolant, and facilitates assembly with the CT device. Inserts cannot function independently and require integration into a complete tube.

Primary Use: These are medical device components used in compatible diagnostic X-ray CT scanners to produce X-rays for medical imaging and diagnostics.

HS Code: Classified under the People’s Republic of China Import and Export Tariff code 90223000. Other products under this code are excluded from the investigation.

(2) Investigation Scope

The industrial competitiveness investigation examines:

The state of the medical CT tube industry in China and major producing/exporting countries (regions) since 2020.

The impact of imported medical CT tubes on the competitiveness of China’s domestic industry.

The anti-dumping investigation specifically targets imports from the U.S. and India, focusing on:

Dumping practices from January 1, 2024, to December 31, 2024.

Injury to the domestic industry from January 1, 2022, to December 31, 2024.

(3) Timeline

Both investigations commenced on April 4, 2025, and are expected to conclude by April 4, 2026, though extensions are possible under special circumstances.

Online sources highlight tungsten’s critical role in medical CT tubes due to its excellent physicochemical properties. X-ray tubes and inserts are key components in CT scanners, and their material selection directly affects X-ray generation efficiency, heat resistance, and longevity. These tubes must operate continuously, produce high-intensity X-rays, and withstand elevated temperatures.

Key materials include:

Cathode: Tungsten or tungsten-rhenium alloy, chosen for its high melting point and electron emission efficiency.

Anode (Insert):

Target surface: Tungsten, for its durability and X-ray production efficiency.

Reinforcement layer: Tungsten-rhenium alloy, enhancing thermal and mechanical stability.

Substrate: Molybdenum, providing structural support.

Heat sink: Graphite, dissipating heat effectively.

Shell: Borosilicate glass or ceramic, maintaining a vacuum to prevent electron scattering.

Window: Beryllium, allowing X-ray transmission.

Cooling: Dielectric oil, water, or copper, managing heat during operation.

Tungsten’s high density (19.25 g/cm³), melting point (3422°C), and thermal conductivity make it ideal for withstanding the intense heat and mechanical stress in CT tubes, ensuring reliable performance over extended use.

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