1 Scope
This specification specifies the technical and quality requirements and test methods for chemistry cleaning of equipment and piping in petrochemical industry.
This specification is applicable to the chemistry cleaning of equipment and piping in the new construction, renovation and extension projects of petrochemical industry. Reference may be made to this specification for the chemistry cleaning of maintenance engineering equipment and piping.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply to this standard. However parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.
GB 8978 Integrated wastewater discharge standard
GB 50484 Technical code for construction safety in petrochemical engineering
HG/T 3523 Technical conditions of standard corrosion spool of chemical treatment in cooling water
HG 20202 Code for construction and acceptance of degreasing project
SH/T 3503 Specification on handover technical documentation for petrochemical construction projects
SH/T 3543 Technical document specification of construction process for petrochemical engineering project
3 Terms and definitions
3.1
chemistry cleaning
surface cleaning method of removing the dirt, oxide, corrosion products, etc. on the surface of the equipment and piping to be cleaned with chemical agents and their aqueous solutions
3.2
cycle cleaning
method of system cleaning by circulating the cleaning solution injected with a circulating pump within the equipment and piping
3.3
immersing cleaning
method of surface cleaning by placing the part to be cleaned into a container filled with cleaning solution or injecting the cleaning solution into the part to be cleaned for immersion
3.4
corrosion rate
relative rate of metal corrosion when chemical agents and their aqueous solutions are in contact with the metal of equipment and piping to be cleaned
3.5
removing dirty stuff rate
percentage of the ratio of the removed dirty stuff amount to the original dirty stuff amount before cleaning
3.6
cleaning rate
percentage of the ratio of the area on which the dirty stuff is removed after chemistry cleaning to the area covered by the original dirt stuff before cleaning
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 General
5 Construction preparation
5.1 Preparation of materials and machine tools
5.2 Technical preparation
5.3 Operating conditions
6 Chemistry cleaning method
6.1 General
6.2 Cycle cleaning
6.3 Immersing cleaning
7 Chemistry cleaning quality standard
8 Safety technical requirements
8.1 General requirements
8.2 Acid and alkali operation
8.3 Degreasing operations
9 Handover technical documentation
Annex A (Informative) Characteristics of chemical agents and common cleaning formulas
Annex B (Normative) Basic procedures of chemistry cleaning
Annex C (Informative) Operation procedures of chemistry cleaning
Annex D (Normative) Determination of corrosion rate, corrosion amount and removing dirty stuff rate
Annex E (Informative) Test methods used in chemistry cleaning
Annex F (Normative) Inspection of passive films
Explanation of wording
