曰韩中文人妻视频|天天视频国产一区97|国产一区二区视频在线观看网址|国产羞羞在线观看|孕妇大肚子一级毛片|360AVcom|亚洲婷婷成人综合|久久精品1234|操女人视频免费网站|av大片无码免费

a.Cut off protective films for 5 to 10mm before inserting PC sheets to the support frame, because the protective films would cause inefficient adhesive between tamping and PC sheets.
b.Since the expansion and contraction degree of PC sheets, are different from that of medal frames, as well as PC sheets are flexible and taking air pressure, therefore, appropriate insertion, reserving space for expansion and shrink because of temperature changes, and choosing suitable thickness of PC sheets are necessary.General plate should be inserted into fixed frame for over 25mm, with at least 2 ribs installed into the fixed zone. 3mm place will be reserved for expansion or shrinkage. (Expansion ratio: 0.065mm/m)

(2)Screw installation

a. When hollow profile and solid sheet are installed with screw installation, all rivet holes should be reamed to reserve space for expansion and contraction. Usually, the holes should be larger than that of the bolt or rivet stems by 50%" so as to avoid expansion or shrinkage. 
b. Fill up the holes, and cover the exposed portion with silicone compound to prevent detergents permeating which brings damage to pc sheets, and avoid gradual cracks.
c. Rivet heads should be larger than the stems by 2 times. Use gaskets or washers to avoid the rivet heads touching pc sheets, and reduce the pressure.
d. Do not screw into too tightly.
e. Do not use gaskets made of PVC.
f. The bending part should be avoided using screw for cold bending process.