elbow piece的用法和樣例：
例句
- Reattach the relief valve hose to the elbow in the bottom flange cover.
重新將安全閥軟管接到底部法蘭蓋內的彎頭上。 - In the previous works only the uniform wall-thickness elbows were studied.However, the elbow thickness is varied with the bending radius and ellipticity on the cross section.
以往對彎頭的研究只考慮壁厚均勻不變的情況，但是實(shí)際上彎頭的壁厚是沿著(zhù)彎曲半徑變化的，并且彎頭的截面也具有一定的橢圓度。
