HS Code for Thyratron

A thyratron is classified under HS code 854089. This classification falls within Chapter 85, which encompasses electrical machinery and equipment. Heading 8540 is dedicated to thermionic, cold cathode, or photo-cathode valves and tubes, such as vacuum tubes, vapor-filled tubes, and cathode-ray tubes. A thyratron is a type of gas-filled hot-cathode tube that acts as a high-power electrical switch and controlled rectifier. Because it is a specialized valve that does not fit into the more specific subheadings like television picture tubes (854011) or magnetrons (854071), it is categorized under the residual subheading 854089, which covers "other" valves and tubes. The classification is based on the physical construction of the device as a vacuum or gas-filled tube rather than a solid-state semiconductor.

Products Included

• Hydrogen thyratrons
• Mercury-vapor thyratrons
• Shield-grid thyratrons
• Gas-filled triode tubes
• High-voltage switching tubes
• Industrial rectifier tubes (non-solid state)

Common Misclassification

The most frequent misclassification for a thyratron is HS code 854130, which covers thyristors (SCRs). While thyristors perform a similar electronic switching function, they are solid-state semiconductor devices. Thyratrons, by contrast, are vacuum/gas tubes and must remain in 8540. Another error is classification under 8535 or 8536 as general electrical switches; however, because the thyratron is an electronic valve, the specific heading for tubes (8540) takes precedence over general switching apparatus.

FAQ

What is the HS code for a thyratron tube?

The HS code for a thyratron tube is 854089.

How do I distinguish a thyratron from a thyristor for HS classification?

A thyratron is a glass or ceramic tube containing gas or a vacuum (8540), whereas a thyristor is a solid-state silicon-based component (8541).