4.1 Technicaldocuments shall be developed,reviewed and approved for anticorrosive coating.

Method:checking documents.

4.2 Construction of anticorrosive coating shall meet the requirements of design documents and this Specification.Classification of item project,and inspection lot,item project for construction of anticorrosive coating shall conform to the Unification Criterion of Construction Quality Check and Acceptance for Petrochemical Engineering Project Installation(SH/T 3508).And split of inspection lots for construction of anticorrosive coating shall follow this Specification.

Method:checking documents.

4.3 Corrosion resistant materials shall be provided with quality certificates and quality inspection reports,while its performance indicators should comply with design documents or product technical documents.If any doubt is raised on product quality,a field sampling shall be witnessed and submitted for re-examination.

Method:checking documents.

4.4 During sampling inspection,any disqualification found in one sample will increase the sample quantity to two times of the original sampling,if further defect foundin the additional sampling,allitems in this lot shall be rejected.

Method:checking documents.

4.5 Painting of weldjoints on equipment and piping shall be performed after heat treatment and pressure test.

Method:checking documents.

4.6 Subsequent operations shall not proceed if the concealed works of anticorrosive coating is not checked and accepted.

Method:checking documents.

4.7 Split of main control items and general items for construction quality of anticorrosive coating on exterior surfaces of equipment,piping and steel structure is shown in Table 1.