… including pressure-reducing valves and thermostatically controlled valves. …
Explanatory notes
… regulate the flow (for supply, discharge, etc.), of fluids (liquid, viscous or gaseous), or, in certain cases, of solids … to be mounted directly on the tap, valve, etc., and provided the combined apparatus has the essential character … of an article of this heading. If not satisfying these conditions, they are classified in heading 90.26 (e.g., …