u-shaped bend弯管
U-bend tubeU形管
U-bend U形弯头
U-bend tubeU形传热管
u-bend specimenU型弯曲试样
U-bend dieU型弯曲模
u-bend buried coilu型埋管
u-bend tube u形管
N（名词） a U-shaped bend in a pipe or drain that traps water in the lower part of the U and prevents the escape of noxious fumes or vapours; trap (管的)U型弯