This standard is applicable to the internal surface of steel pipe welds with various specifications and nominal diameters of 200-600mm using liquid coating patching machines. SY/T 4078-1995 Internal coating of steel pipes using liquid coating patching machines SY/T4078-1995 Standard download decompression password: www.bzxz.net

People's Republic of China Petroleum and Natural Gas Industry Standard Steel Pipeline Internal Coating Liquid Paint
Packing Machine Patching Process
Technological process of inncr coating fotwelded jint with liguid paint by spccialmachine for steel pipeline
SY/ T 4078-95
Editor: Shengli Petroleum Administration Bureau Oil Construction No. 1 Company Approval Department: China National Petroleum Corporation Petroleum Industry Press
1995 Beijing
Terms and Symbols
Construction Process Flow Chart
Construction Preparation
Construction Process Conditions
Liquid Coating Preparation
Equipment and Construction Personnel Arrangement
Pipe Section Detection
Work Step Flow Chart
Equipment, Position Setting and Personnel Arrangement
Surface Layout Diagram
Operation Points|| tt||Packing inside the pipe section
Process flow chart
Equipment,
Post setting and staffing
Schematic diagram of plane layout
Key points of operation
Quality inspection
Inspection and repainting of patching inside the pipe section
Process flow chart
7.2 Equipment,
Post setting and staffing
Schematic diagram of plane layout
Key points of operation
(10）
(11）
(12）
(15）
Pipe section Assembly, internal patching at interfaces and inspection and repainting of internal patching of special welds
Inspection
Appendix A
Appendix B
Appendix C
Appendix D
Appendix E
Appendix F
Equipment of construction equipment, instruments and tools·
Equipment of construction personnel
Equipment of pipe section detection equipment and parameter adjustment
Equipment of internal patching of pipe section and parameter adjustment (20)
(29)
Equipment of internal patching detection and repainting of pipe section and parameter adjustment (32) Terms used in this standard Description
Additional description
Description of the process of steel pipe internal coating liquid coating patching machine
(34）
(35）)
Document of China National Petroleum Corporation
(95) CNPC Technical Supervision No. 156
Notice on the approval and release of one oil and gas industry standard including "Safety Regulations for Heating Furnaces Used in the Petroleum Industry" To all relevant units:
Eleven standards (drafts) including "Safety Regulations for Heating Furnaces Used in the Petroleum Industry" have been reviewed and passed and are now approved as oil and gas industry standards and can be released. The numbers and names of the standards are as follows:
SY 003195
SY 7T 008695
SYT 4074--95
4075-95
SY / T 4076-95
SY/T 4077-95
Safety regulations for heating furnaces used in the petroleum industry (replacing SYJ 31-88)
Electrical insulation standards for cathodic protection pipelines
Coating process of cement mortar lining of steel pipelines by coating machine
Centrifugal forming construction process of fly ash cement mortar lining of steel pipelinesbzxz.net
Pneumatic extrusion coating process for inner coating of liquid paint for steel pipelines
Pneumatic extrusion coating process for cement mortar lining of steel pipelines
SY 7T 4078
SYT 4079-
SY/T 4080-95
SY 408I-95
SYT4082--95
Liquid coating for internal coating of steel pipelines
Specifications for construction and acceptance of petroleum and natural gas pipeline crossing projects
Leakage detection methods for pipelines and storage tanks
Technical standards for seismic inspection of steel spherical storage tanks
Construction and acceptance standards for equipment and pipeline installation projects in gas field well sites
The above standards shall be implemented from September 1, 1995 China National Petroleum Corporation
March 11, 1995
Central. 1 This standard is specially formulated to improve the coating process of liquid coating for internal coating of steel pipelines, ensure the quality of the patching construction of liquid coating for internal coating of steel pipes, and extend the service life of steel pipelines.
0.2This standard applies to the liquid coating patching machine patching construction of various specifications of steel channel welds with a nominal diameter of 200-600m110.3
Use standard
GB 172079
GBT 1723-
GB 172479
GB 172579
GB 172879
GB 7T 1731-
GB T 1732-
GB /T 1733
GB 176379
GBT 1771-
GB 318688
GB 479284
GB 6739
GB7T 8923
SYJ 402288
SYJ 404289
SYJ 4047---90
Text specification
SY 006692
Determination of adhesion of paint film
Determination of viscosity of paint
Determination of fineness of paint
Determination of solid content of paint
Determination of drying time of paint film and putty film
Determination of toughness of paint film
Determination of impact resistance of paint film
Determination of chemical resistance of paint film
Determination of neutral salt mildew resistance of paint and varnish Sampling of paint products
Basic standards for radiation health protection
Determination of hardness of paint film by pencil method
88Rust grade and rust removal of steel surface before painting Construction and acceptance specifications for oilfield gathering and transportation pipelines
Technical standard for powder coating of steel pipelines
Construction and inspection of epoxy coal asphalt anti-corrosion coating for buried steel pipelines Standard for non-destructive measurement of the thickness of the anti-tumor layer of steel pipes (magnetic method
SY/T4057--93 Technical conditions for steel pipes with liquid epoxy coatings for internal anti-corrosion coatings In addition to complying with the provisions of 1.0.4 of this standard, the construction of internal coatings of steel pipelines by liquid coatings patching machines shall also comply with the provisions of the relevant current national standards. 2-Terms and symbols
2.1Terms
: 2.1.1·Internal coating liquid coating patching machine patching (referred to as internal patching) inner coat-
ing for welded joint with liguid paint by special machineThe process of applying liquid paint to the inner girth weld of the steel pipe section that has been coated with inner coating after field welding by using a patching machine.
：2.1.2 Machine for welding joint inrer coating in pipelinefield coating
A special equipment used for cleaning and coating the inner girth weld of steel pipeline.
2.1.3 Machine for inspecting and re-coating inner coating of steel pipeline (referred to as inspection and re-coating machine)machine of coating defects inner coating in pipelinerepair
A special equipment used to inspect the quality of steel pipeline patching and re-coat its defects with liquid paint.
2.1.4 Pipeline detection pipeline detection inspection and patching machine enters the steel pipeline before the internal patching construction to check the quality of the previous process and the environmental conditions in the pipeline. 2.1.5 Positioning by resistance means using the principle of sudden change in resistance at the inner wall of the steel pipeline where the inner coating has been applied and the inner ring weld to achieve the positioning of the patching equipment. z.1.6 Positioning by isotope means using the isotope receiver in the patching equipment to receive the signal emitted by the isotope source outside the pipeline: to achieve the positioning of the patching equipment,
2.2 Symbols
The symbols used in the process flow chart of this standard and their explanations are shown in Table 2.2.1Serial number
Symbols and instructions
Construction process
Special inspection at inspection points
Construction work and self-inspection
Including adjustment, maintenance, operation, etc.
Inspection by dedicated departments
Table 2.2.1
Inspection by construction personnel while working
3 Construction process flow chart
The process flow of the internal coating of steel pipelines using liquid coating patching machine should comply with the provisions of Figure 3.0.1.
Work preparation
Smoke blasting
Pipe section internal patching inspection and repainting
Pipe section installation Internal patching at the interface and testing of the internal patching of special welds
Internal patching of pipe sections
Internal coating of steel pipelinesLiquid coating patching machinePacking process flow chart 4 Construction preparation
4.1 Construction process conditions
4.1.1The inner wall of a single steel pipe has been coated with an internal coating, and a 5060mm wide annular belt is reserved inside each of the two ends of the steel pipe. The surface rust removal level should reach Sa21 specified in the "Surface rust level and rust removal level of steel materials before coating", and weldable coating should be applied. 4.1.2. Steel pipe sections after assembly welding: its quality indicators must comply with the relevant provisions of the "Oil Gathering and Transportation Pipeline Construction and Acceptance Specifications". 4.1.3 The length of each natural section of the steel pipe section after assembly welding shall not be less than 1km (preferably 0.5k1): the slope of any part of the pipe section shall not be greater than 7°, and the turning radius (calculated based on the central axis of the pipeline) shall not be less than 100m. 4.1.4 After welding, there should be no mud, water or other debris inside the steel pipe section, and the two ends of the pipe section should be blocked with blind plates. It is not advisable to backfill the trench before the inner patching. The ambient temperature for the inner patching construction should be 5-55℃; the relative humidity should not be greater than 4.1.5
4.2 Liquid coating preparation
42.1 The liquid coating used for the inner patching construction of steel pipelines should comply with the design regulations. If there is no regulation in the design, the construction unit should negotiate with the user unit to determine the type of coating. The determined coating must have the same or similar performance as the coating used for the inner coating of a single steel pipe, and it has good compatibility. Its main indicators should comply with the provisions of Table 4.2.1. 4.2.2 Liquid coatings must have a factory quality certificate from the manufacturer, and samples should be taken according to the sampling method specified in "Sampling of Coating Products" to test the viscosity, fineness, solid content and drying time of the coating. When in doubt about other performance indicators of the coating: it should be inspected according to the test method specified in Table 4.2.1 of this standard. Its performance indicators should comply with the provisions of Table 4.2.1 of this standard.
Liquid coating performance indicators
Viscosity (4 cup Pas)
Fineness (um)
Adhesion (grade)
Flexibility (mm)
Impact resistance (J)
Hardness (2H pencil)
Drying time||tt ||Solid content
Chemical reagent resistance
(180d)
Component A
Component B
10%Na0H
10%NaCl
Salt resistance (500)
Sewage resistance (00,
3 months)
No scratches
No scratches
4.3 Equipment and construction personnel
Test method
GB/ T 1723
GB1724
GB 1720
GB/T 1731
GB /T 1732
GB 6739
GB 1728
GB 1725
GB 1763
GB/T 1771
GB/T1733(z method)
4.3.1· The configuration of construction equipment, instruments and tools may refer to the provisions in Appendix A of this standard.
The configuration of construction personnel may refer to the provisions in Appendix B of this standard.
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