丁香免费久久久久久,无码av专区丝袜专区,亚洲av片不卡无码一动漫,亚洲另类无码专区丝袜,亚洲小说综合专区,悠悠乱伦一区二区三区,国产女主播白浆在线观看

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.