5.2　Metal Surface Preparation

5.2.1　Metal surface shall be de-rusted by sand（shot）blasting，and power tools may be used for local derust operation.

5.2.2　The surface to be lined shall be cleaned after de-rust，and metal surface shall be protected against rain prior to lining application.

5.2.3　Erection of soft rubber caps on Ω-anchors and binding of refractory ceramic fiber paper over the pipes and other components inserted in lining shall be made after de-rust is completed.

5.2.4　Protection measures shall be taken for the threads of stud blots used for dual-layer ring anchors prior to de-rust.