Explanatory notes
… or section (straight, curved, branched, of constant or varying diameter, etc.), and may be glazed. The heading … These pipes, etc., may be of unglazed common pottery, but are often rendered impermeable by glazing or by … piping). (3) Pipe fittings for connecting or branching (collars, flanges, elbows, T-pieces, clean out traps, etc.). …