管道排水，暗管排水

暗管改碱技术试验区不同生境盐生植物资源及其群落特征

pipe assembly

pipe elbow, duct bend

water tank antifreezing steam pipe【船】

pipe fracturing before pipe replacing

syphon(pipe,tube)

stainless steel pipe【材】;stainless steel tube【材】

feed pipe with nozzle

header pipe