right-angled loop (plumbing); torii-shaped piping
Technical plumbing term for a pipe configuration that resembles a torii gate, forming a right-angled loop or expansion pipe.
In this piping diagram, a torii-shaped loop is used to absorb thermal expansion.
Compound of 鳥居 (torii, 'shrine gate') and 配管 (haikan, 'piping'), named for the shape's resemblance to a torii gate.