The line block valves are of vital importance for the safety operation of the pipeline.
线路截断阀是管道安全运行的重要保证。
Line block a relief plate produced from a line drawing.
线条凸版用线条画所制成的凸版。
Line block: a relief plate produced from a line drawing.
线条凸版：用线条画所制成的凸版。
Line block: a relief plate produced from a line drawing.
线条凸版：用线条画所制成的凸版。
应用推荐