1. We usually use elbow( bend, flange, tee, reducer) as a kind of pipe fitting.
我们常用弯头(弯管、法兰、三通、大小关)作为一种管件。
来自互联网
2. Leather cap type pig has higher abrasion during pigging gas steel pipeline. Furthermore, various elbow bend and tee joint need different suitable length pig or else easy to cause pipeline clog.