SY/T 7821-2024 Code for quality acceptance ofoil and gas construction engineeringAnti-corrosion project for steel pipeline English, Anglais, Englisch, Inglés, えいご
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ICS
E
Professional standard of the People's Republic of China
SY/T 7821-2024
Code for quality acceptance of oil and gas construction engineering Anti-corrosion project for steel pipeline
石油天然气建设工程施工质量验收规范 钢质管道防腐工程
(English Translation)
Issue date: 2024-12-25 Implementation date: 2025-06-25
Issued by National Development and Reform Commission, P.R.C
Contents
1 General provisions
2 Terms
3 Basic requirement
4 Acceptance and storage of materials
4.1 Steel pipesand fittings
4.2 Coating materials
5 Division of project units
6 External coating
6.1 General requirements
6.2 Fusion bonded epoxy powder coating
6.3 Coal tar epoxy coating
6.4 Liquid epoxy coating
6.5 Solvent free polyurethane coating
6.6 Polyethylene coating
6.7 Polypropylene coating
6.8 Polyolefin tape coating
6.9 UV resistant three-layer fusion bonded powder coating
6.10 Coating for above-ground pipeline
6.11 Glass fiber reinforced epoxy armoring coating for crossing pipeline
7 Internal coatings
7.1 General requirements
7.2 Cement mortar lining
7.3 Fusion bonded epoxy powder coating
7.4 Liquid epoxy coating
8 External coatings for steel pipes in station
8.1 General requirements
8.2 Coating for above-ground pipes
8.3 Multi-layer coating for buried pipes
9 External joint coating and repair
9.1 General requirements
9.2 Joint coating of heat-shrinkable sleeve
9.3 Liquid joint coatings
9.4 Polymer tape joint coatings
9.5 Viscoelastic joint coatings
9.6 Epoxy powder joint coatings
9.7 Repair of coatings
10 Internal joint coating
10.1 General requirements
10.2 Cement mortar joint coatings
10.3 epoxy joint coatings
10.4 Prefabricated inner coating of corrosion resistant alloy
11 Handover and acceptance
Appendix A Inspection batch quality acceptance record
Appendix B Quality control data verification record
Appendix C Apparatus used for testing the quality of projects
Explanation of wording in this code
List of quoted standards
Addition: Explanation of provisions
1 General Provisions
1.0.1 This code is formulated to strengthen the quality management of petroleum and natural gas construction projects, unify the construction quality acceptance requirements for anti-corrosion coating engineering of steel pipelines, and ensure project quality.
1.0.2 This code applies to the construction quality acceptance of external anti-corrosion coatings, including fusion bonded epoxy, coal tar epoxy, liquid epoxy, solvent-free polyurethane, polyethylene, polypropylene, and polyolefin tape coatings, as well as field joint coating and coating repair engineering for general pipeline projects, crossing projects, and station projects of new construction, renovation, and expansion projects of steel pipelines.
1.0.3 This code applies to the construction quality acceptance of internal anti-corrosion coatings, including cement mortar lining, fusion bonded epoxy, liquid epoxy, and solvent-free polyurethane coatings, as well as field joint coating engineering for new construction, renovation, and expansion projects of steel pipelines.
1.0.4 This code shall be used in conjunction with the current national standard "Unified Standard for Construction Quality Acceptance of Petroleum and Natural Gas Engineering" GB/T 51317.
1.0.5 The construction quality requirements specified in the technical documents and contract documents adopted for anti-corrosion coating engineering of steel pipelines shall not be lower than the provisions of this code.
1.0.6 In addition to complying with this code, the construction quality acceptance of anti-corrosion coating engineering of steel pipelines shall also comply with current relevant national standards.
2 Terms
2.0.1 coating
A protective layer applied to a metal surface to isolate it from the surrounding environment and inhibit corrosion.
Note: Coatings formed from paints may also be referred to as paint films.
2.0.2 armoring coating
A protective structure applied over the surface of external anti-corrosion coatings of pipelines and equipment.
2.0.3 surface preparation
The process of treating attached matter or generated foreign substances on the substrate surface to improve the adhesion between the substrate surface and the coating or to impart certain corrosion resistance to the surface.
Note: Methods of surface preparation typically include abrasive blasting, or manual or power tool cleaning.
2.0.4 grade of surface finish
The classification of the degree of removal of rust from the surface of ferrous steel.
2.0.5 profile depth
The distance between the peak line and the valley line of the contour within the sampling length.
Note: It determines the minimum thickness value of the coating, also known as "maximum profile depth", or simply "profile depth".
2.0.6 pneumatically-pig-squeezed
A coating process where compressed air is used to propel a squeegee device at a uniform speed inside the pipeline, evenly applying the anti-corrosion material onto the internal surface of the steel pipe.
2.0.7 joint coating
Anti-corrosion work performed at the welded joint connecting two pipe sections.
2.0.8 coating repair
The process of repairing damaged areas of an anti-corrosion coating according to corresponding technical requirements.
2.0.9 holiday
A discontinuity in the anti-corrosion coating that results in the exposure of the unprotected surface to the environment.
2.0.10 anticorrosion petrolatum tape
A tape-shaped anti-corrosion material made by impregnating a non-woven fabric carrier with a special mineral grease containing复合 rust inhibitors, corrosion inhibitors, thickeners, lubricants, fillers, etc. Abbreviated as "petrolatum tape".
2.0.11 non-crystalline low-viscosity adhesive
A non-crystalline, low-viscosity polyolefin polymer, primarily composed of modified polyisobutylene and fillers.
2.0.12 polyolefin tape
A tape-shaped anti-corrosion material composed of a polyolefin backing and a pressure-sensitive adhesive layer.
2.0.13 polyolefin tape coating
An anti-corrosion coating formed by wrapping polyolefin tape around the outer wall of a pipeline that has been primed with a primer.
2.0.14 fusion bonded epoxy coating
An anti-corrosion coating formed by applying fusion bonded epoxy powder onto a preheated metal surface using electrostatic spraying, where it melts and cures.
2.0.15 extruded polyethylene coating
An anti-corrosion coating formed by applying polyethylene in a flowing state, continuously through an extrusion die, onto a pipeline under heat and pressure using an extruder. Application methods include longitudinal extrusion and side-wrap. Abbreviated as "polyethylene coating".
2.0.16 solvent-free polyurethane coating
A coating typically composed of two components: one being an isocyanate monomer or polymer, and the other being a polyol. When mixed in proportion, they react to form a polyurethane coating.
2.0.17 solvent-free liquid epoxy coating
A solid film formed by mixing and curing the two components of a solvent-free liquid epoxy coating using a specified application process. Abbreviated as "liquid epoxy".
2.0.18 procedure qualification trial
The coating application and inspection/testing conducted before construction begins to confirm that a coating with specified properties can be obtained by following the application procedure specification (APS).
2.0.19 adhesion
The sum total of the bonding forces between the anti-corrosion coating and the substrate.
2.0.20 peel strength
The force required to peel the anti-corrosion coating from the metal surface under specified test conditions.
2.0.21 cathodic disbondment
The destruction of adhesion between the anti-corrosion coating and the coated metal surface caused by cathodic protection.
2.0.22 corrosion resistant alloy prefabricated inner mending
The use of corrosion-resistant alloy applied through factory-end internal cladding or lining, followed by on-site assembly and welding, to form a continuous anti-corrosion layer with the pipeline's internal anti-corrosion coating.
3 Basic Provisions
3.0.1 Contractors undertaking anti-corrosion coating construction for steel pipelines shall possess corresponding construction qualifications, key project management personnel shall have corresponding qualifications, and construction operators shall work with appropriate certifications.
3.0.2 The construction site quality management system shall establish a quality management system and corresponding quality management systems, be equipped with construction technical standards and quality acceptance standards, inspection instruments shall be verified or calibrated, and shall have qualification certificates or calibration reports, and be within the validity period.
3.0.3 The construction unit shall prepare a construction organization design or work instructions, carry out procedure qualification trials according to current relevant national standards, and prepare application procedure specifications for the anti-corrosion coating.
3.0.4 New technologies, processes, materials, and equipment shall be verified, assessed, or approved through testing.
3.0.5 The application of anti-corrosion coatings and joint coating shall be carried out under environmental conditions specified in the material instruction manual and shall meet environmental protection requirements. Outdoor construction shall not be carried out under any of the following conditions without effective protective measures:
1 Rainy, snowy, or sandy weather.
2 Wind force reaching level 5 or above.
3 Ambient relative humidity exceeding 85%.
4 Pipe body surface temperature below the temperature recommended by the anti-corrosion material manufacturer.
3.0.6 During storage, handling, and transportation of coated pipes, protective measures shall comply with current relevant national standards.
3.0.7 The organization and procedure for construction quality acceptance of steel pipeline anti-corrosion coating engineering, as well as the quality acceptance records for inspection lots, individual items, sub-divisional (sub-) works, and unit (sub-unit) works, shall be carried out according to the relevant provisions of the current national standard "Unified Standard for Construction Quality Acceptance of Petroleum and Natural Gas Engineering" GB/T 51317.
