9026.90 - Parts and accessories:

This HTS category, 9026.90, encompasses all parts and accessories specifically designed for use with instruments and apparatus that measure or check the flow, level, pressure, or other variables of liquids or gases. This broad definition includes components for devices like flow meters, level gauges, manometers, and heat meters, excluding those classified under headings 9014, 9015, 9028, or 9032. The key criterion for classification here is that the part or accessory is integral to the function of an instrument falling within the scope of heading 9026.

Distinguishing this category from its siblings, 9026.10, 9026.20, and 9026.80, is straightforward. Those sibling categories classify the complete instruments themselves based on their primary function (flow/level, pressure, or other variables, respectively). Category 9026.90, conversely, is for the individual components, replacement parts, or supplemental items that enable these instruments to operate. For instance, a replacement diaphragm for a manometer would be classified under 9026.90, while the complete manometer would fall under 9026.20.

Within category 9026.90, further subdivision exists to refine classification based on the nature of the instrument. The subcategory 9026.90.20.00 specifically covers parts and accessories for electrical instruments and apparatus within this group. The remaining "Other" designation captures parts and accessories for non-electrical instruments or those where the electrical component is not the defining characteristic of the part. This distinction is crucial for accurate tariff application.