中文字幕韩国理伦片,久久久最新精品,香蕉av免费,香蕉av免费,91精品国产色综合久久不卡98,1717she,国产精品wwww

skills requirement:

●The surface is flat, the dimensional error is no more than 2mm, and there is no distortion.

●The weld seam is clear, no blisters, and no leakage after 3MPa water pressure test.

●The water in the water flows smoothly, and does not deform under the pressure of 3 MPa.

●Water mist, sizing, oil mist erosion.

●Material SUS304.