小龙头
小型旋塞(阀)
小旋塞
扭塞

pet \pet\, a.
Petted; indulged; admired; cherished; as, a pet child; a pet
lamb; a pet theory; a pet animal.

Some young lady's pet curate. --F. Harrison.

{Pet cock}. [Perh. for petty cock.] (Mach.) A little faucet
in a water pipe or pump, to let air out, or at the end of
a steam cylinder, to drain it.