Readings & Meanings:
During admission to the hospital, they put a tube down his throat so he could take nourishment.
The pipes froze from the cold and got a crack in them.
Keep tight control over the key.
竹, Take-kammuri, or bamboo-crown is the radical.
官, the phonetic, is the one we just learned, showing a pileup of bureaucrats in a government building.
You may have noticed that "pipe" and "control" have very little to do with each other. This is because the "control" meaning is an atavistic meaning, which means that it comes from just one part of the kanji (官) instead of the whole.
As for "pipe," the 竹 up top indicate bamboo, and 官 shows an enclosure. A pipe/flute is made from a cylindrical, enclosed object.