SY/T 0420-1997 Technical standard for petroleum asphalt anticorrosion coating for buried steel pipelines
Some standard content:
1 General Principles
Petroleum and Natural Gas Industry Standard of the People's Republic of China Petroleum Asphalt Anticorrosive Coating Technical Standard for Buried Steel Pipelines
Approval Department: China National Petroleum Corporation Approval Date: 1997-12-28 wwW.bzxz.Net
Implementation Date: 1998-06-01
SY/T 0420--1997
Replacement: SYJ4020-1988
SYJ 8--1984
1.0.1 This standard is formulated to ensure the quality of the petroleum asphalt anticorrosive coating, extend the service life of buried steel pipelines, and improve economic benefits. 1.0.2 This standard applies to the design, prefabrication, construction and acceptance of the petroleum asphalt outer anticorrosive coating of buried steel pipelines with a medium temperature not exceeding 80°C. Petroleum asphalt outer anticorrosive pipelines are not allowed to be laid underwater or in swamps and reed areas. 1.0.3 The industrial hygiene and environmental protection issues involved in the design, prefabrication and construction process of this standard shall be implemented in accordance with the provisions of "Industrial Enterprise Design Hygiene Standard" TJ36, "Painting Operation Safety Regulations Pre-treatment Process Safety" GB7692 and "Painting Operation Safety Regulations Pre-treatment Process Ventilation Purification" GB7693. 1.0.4 In addition to complying with the provisions of this standard, the design, prefabrication, construction and acceptance of petroleum asphalt external anti-corrosion layer shall also comply with the provisions of the relevant mandatory standards currently in force in the country.
2 Materials
2.1 General provisions
2.1.1 Raw materials shall be inspected when entering the factory. If any of the following conditions are found, they shall not be used: 1 There is no factory quality certificate or inspection certificate; 2 The data in the factory quality certificate is incomplete or there is doubt about the data, and it has not been re-inspected or has failed the re-inspection. 2.2 Steel pipes
2.2.1 The appearance of steel pipes shall be inspected and measured one by one, and their appearance and dimensional deviation shall comply with the provisions of the current relevant steel pipe manufacturing standards. 2.2.2 The quality of steel pipes shall be subject to targeted mechanical property tests, chemical composition analysis or non-destructive testing, and qualified ones shall be used. 2.2.3 The acceptance, verification inspection and non-destructive testing of high-pressure steel pipes shall be carried out in accordance with the provisions of "Industrial Pipeline Engineering Construction and Acceptance Code (Metal Pipeline)" GBJ235.
2.3 Petroleum asphalt materials
2.3.1 The selection of petroleum asphalt materials shall comply with the following provisions: 1 When the temperature of the pipeline conveying medium does not exceed 80℃, pipeline anti-magic petroleum asphalt shall be used, and the quality indicators of pipeline anti-corrosion petroleum asphalt shall comply with the provisions of Table 2.3.1. When the temperature of the pipeline conveying medium is lower than 51℃, No. 10 construction petroleum asphalt can be used, and its quality indicators shall comply with the provisions of "Construction Petroleum Asphalt" GB494. Table 2.3.1 Pipeline anticorrosion petroleum leaching quality index item
Peeling depth (25℃, 100g) (0.1mm) Elongation (25℃) (cm)
Quality index
Test method
GB/T 4509--1984
GB/T 4508--1984
Softening point (ring and ball method) (℃)
Solubility (benzene) (%)
Flash point (open cup) (℃)
Wax content (%)
Note: GB/T4509-1984
Method for determination of needle penetration of petroleum asphalt
GB/T4508-1984Method for determination of ductility of petroleum asphaltGB/T4507--1984Method for determination of softening point of petroleum asphaltQuality index
≥125
≥260
GB/T11148--1989Method for determination of solubility of petroleum asphaltGB/T267-1988Method for determination of flash point and fire point of petroleum products (open cup method)GB/T260-1977Method for determination of moisture content in petroleum productsSY/T 0420-1997
Test method
GB/T 4507—1984
GB/T 11148--1989
GB/T 267--1988
GB/T 260—-1977
See Appendix A of this standard
2 Petroleum asphalt should not contain soil, weeds, shredded paper and other debris. Petroleum asphalt should be stored according to different grades after entering the warehouse and properly kept. Before use, it should be inspected, checked and tested as required. 2.4 Medium alkali glass cloth
2.4.1 Medium alkali glass cloth (hereinafter referred to as glass cloth) should be a mesh plain weave cloth with single edges on both sides of the cloth. Its performance and specifications should comply with the provisions of Table 2.4.1.
Performance and specifications of medium-alkali glass cloth
Alkali content
Performance and
Test method
Not more than
Original yarn number×number of strands
(Metric count/number of strands)
(45.4/8)
Nominal
diameter of single fiber (μm)
0.100±0.010
Perform according to the provisions of "Test Methods for Glass Fiber Products" JC176-1980 Note: The packaging of glass cloth should be moisture-proof. Density
(piece/cm)
(9±1)
(9±1)
200250
(with shaft core
$40×3 mm)
2.4.2 The warp and weft density of glass cloth should be even, the width should be consistent, and there should be no local breaks and holes. The warp and weft density should be selected according to the construction temperature according to Table 2.4.2.
Table 2.4.2 Warp and weft density of glass cloth used under low temperature conditions Construction temperature (℃)
Warp and weft density of glass cloth (piece×piece/cm2) (8±1)×(8±1)
(9±1)X(9±1)
2.4.3 When anti-corrosion is applied to steel pipes of different diameters, the width of the glass cloth should be selected according to Table 2.4.3. 805
SY/T 0420-1997
Outer diameter of tube (mm)
630~-720
426~630
2.5 Polyvinyl chloride industrial film
Table 2.4.3 Width of glass cloth
Width of glass cloth (mm)
500~600
400-~500
Outer diameter of tube (mm)
245426
≤219
Width of glass cloth (mm)
300～400
2.5.1 Polyvinyl chloride industrial film shall not have local fractures, wrinkles and holes, and the edges shall be neat. The width should be the same as that of glass cloth. Its performance indicators shall conform to the requirements of Table 2.5.1.
Table 2.5.1 Performance index of polyvinyl chloride industrial film
Tensile strength (longitudinal and transverse) (MPa)
Elongation at break (longitudinal and transverse) (%)
Cold resistance (℃)
Heat resistance (℃)
Thickness (mm)
Length (m)
Performance index
≥200
0.2±0.03
200~～250
(with mandrel±40×3)
Note: ①Heat resistance test requirements: 101℃±1℃, 7d elongation retention 75%. When the monthly average temperature during construction is higher than -10℃, there is no cold resistance requirement. ③ The full name of the standard cited in the table is "Test Method for Tensile Properties of Plastics" GB/T1040--1992. 3 Anti-corrosion exhibition structure
The structure of petroleum asphalt anti-corrosion layer of various anti-corrosion grades shall comply with the provisions of Table 3.0.1. 3.0.1
Structure of petroleum asphalt anti-corrosion layer
Anti-corrosion grade
Total thickness of anti-corrosion layer (mm)
Anti-corrosion layer structure
Ordinary grade
Three oils and three cloths
One layer of primer
Petroleum asphalt thickness ≥1.5 mm
One layer of glass cloth
Petroleum asphalt thickness 1. 0~1. 5 mm
One layer of glass cloth
Petroleum asphalt thickness 1. 0~1. 5mm
Outer protective layer
Reinforced grade
Four oils and four cloths
One layer of primer
Petroleum asphalt thickness ≥1.5mm
One layer of glass cloth
Petroleum asphalt thickness 1.0~1.5mm
One layer of glass cloth
Petroleum asphalt thickness 1.0~1.5mm
One layer of glass cloth
Petroleum asphalt thickness 1. 0~1.5 mm
Outer protective layer
Petroleum asphalt anti-corrosion outer protective layer should use polyvinyl chloride industrial film. The thickness of the anti-corrosion layer at the weld of the steel pipe should not be less than that in Table 3.0.165% of the specified value. Test method
GB/T 1040-1992
GB/T 1040---1992
See Appendix B of this standard
See Appendix C of this standard
Micrometer (micrometer) measurement
Extra-reinforced grade
Five oils and five cloths
One layer of primer
Petroleum asphalt thickness ≥ 1.5mm
Glass cloth layer
Petroleum asphalt thickness 1. 0~1. 5 mm
One layer of glass cloth
Petroleum asphalt thickness 1.0~1.5mm
One layer of glass cloth
Petroleum asphalt thickness 1.0~1.5mm
One layer of glass cloth
Petroleum asphalt thickness 1.0~1.5mm
Outer protective layer
4 Anti-corrosion coating
4.0.1 The surface pretreatment of steel pipes before anti-corrosion should meet the following requirements: 1 Remove welding slag, burrs, grease, dirt and other attachments on the surface of the steel pipe; 2 Preheat the steel pipe at a preheating temperature of 40~60℃; SY/T 0420—1997
3 Use spraying (blasting) or mechanical rust removal, and its quality should meet the requirements of Sa2 or St3 specified in GB/T8923 "Surface Rust Grade and Rust Removal Grade of Steel Materials Before Coating"; 4 After surface pretreatment, the defects revealed on the surface of the steel pipe should be treated, and the dust and abrasive attached to the surface of the steel pipe should be cleaned up, and the surface of the steel pipe should be prevented from being damp, rusted or secondary contaminated before coating. 4.0.2 Boiling asphalt should meet the following requirements: 1 Before boiling, it is advisable to break the asphalt into blocks with a particle size of 100-200mm, and remove paper scraps, soil and other debris. 2 The boiling of petroleum asphalt can be done by melting the asphalt in an asphalt pot or indirectly melting the asphalt with heat transfer oil. At the beginning of boiling, the temperature should be slowly increased, and the boiling temperature should be controlled at about 230℃, and the maximum heating temperature should not exceed 250℃. Stir frequently during boiling, and remove floating objects on the surface of petroleum asphalt. The boiling time of petroleum asphalt should be controlled within 4 to 5 hours to ensure complete dehydration. 3 The boiled petroleum asphalt should be tested for three indicators, namely, penetration, elongation and softening point, one pot at a time (when boiling petroleum asphalt continuously, it should be tested by shift batches), and the test results should comply with the provisions of Article 2.3.1 of this standard. 4.0.3 The application of primer should meet the following requirements: 1 The petroleum asphalt used for primer should have the same grade as the petroleum asphalt used for topcoat. It is strictly forbidden to use leaded gasoline to prepare primer. The gasoline used to prepare primer should be precipitated and dehydrated. The volume ratio of petroleum asphalt to gasoline (relative density of gasoline is 0.80 to 0.82) should be 1: (2 to 3) when preparing primer. 2 The surface of the steel pipe should be dry and dust-free before applying primer. 3 The primer should be applied evenly, without missing any spots, and without defects such as clots and flow marks. The thickness should be 0.1 to 0.2 mm. 4.0.4 The application of petroleum asphalt and the coating of glass cloth shall meet the following requirements: 1 The time interval between the application of primer and the application of petroleum asphalt at room temperature shall not exceed 24 hours. 2 The temperature for the application of petroleum asphalt shall be preferably 200-230℃. 3 After the application of petroleum asphalt, the glass cloth shall be wrapped immediately. The glass cloth must be dry and clean. The wrapping shall be tight and wrinkle-free, the edge shall be evenly hooked, the edge width shall be 20-30mm, and the lap length of the glass cloth joint shall be 100-150mm. The petroleum asphalt penetration rate of the glass cloth shall reach more than 95%, and it is strictly forbidden to have a blank space larger than 50mmX50mm. A section shall be reserved at both ends of the pipe according to the pipe diameter without the application of petroleum asphalt, and the length of the reserved section at the pipe end shall be 150-200mm. The anti-corrosion layer at both ends of the steel pipe should be made into a gentle slope joint. 4.0.5 The selected polyvinyl chloride industrial film should be adapted to the temperature of the pipe body during winding, and can only be used after passing the on-site test wrapping; the outer protective layer wrapping should be loose and tight, without damage, wrinkles, and shelling. The edge should be evenly hooked, the edge width should be 20-30mm, and the overlap length should be 100-150 mm.
4.0.6 Except for taking special measures, it is strictly forbidden to carry out open-air anti-corrosion operations in rain, mist, fog and strong winds. 4.0.7 When the ambient temperature is lower than -15℃ or the relative turbidity is greater than 85%, the anti-corrosion operation of the steel pipe shall not be carried out without taking reliable measures.
4.0.8 When the ambient temperature is lower than 5℃, the brittle temperature of petroleum asphalt shall be determined according to the provisions of GB/T4510 "Determination of Brittle Point of Petroleum Asphalt". When the ambient temperature is close to the brittle temperature, the hoisting and handling of the anti-corrosion pipe shall not be carried out. 5 Quality inspection of anti-corrosion pipes
5.1 Quality inspection of production process
5.1.1 Manufacturers of anti-corrosion coatings shall be responsible for production quality inspection and keep records. 5.1.2 Quality inspection of surface pretreatment: After surface pretreatment, the steel pipes shall be inspected for surface rust removal level one by one, and visually compared with the corresponding photos in GB/T8923. The surface rust removal level shall meet the requirements specified in Article 4.0.1, Paragraph 3 of this standard. 5.1.3 Appearance inspection: The appearance quality of the anti-corrosion layer shall be inspected one by one by visual inspection. The surface shall be flat without obvious bubbles, pitting, wrinkles, convex marks and other defects. The outer protective layer shall be pressed evenly and without wrinkles. 5.1.4 Thickness inspection: The anti-corrosion level and the total thickness of the anti-corrosion layer shall comply with the provisions of Table 3.0.1 of this standard. Use the anti-corrosion layer thickness gauge to test, and sample 10% of the number of anti-corrosion pipe products produced on each shift that day, and not less than 1 pipe. Measure 3 sections for each pipe, and measure 4 points on the top, bottom, left and right of each section, with the thinnest point as the standard. If it is unqualified, double the number of samples; if there is still one unqualified pipe, the anti-corrosion pipe produced by this shift is unqualified.
5.1.5 Adhesion inspection: On the pipeline anti-corrosion layer, cut an incision with an angle of 45°~60, and the side length of the incision is about 40~50mm. Tear off the anti-corrosion layer from the tip of the corner, and the tearing area should be 30~50cm. The anti-corrosion layer should not be easy to tear off, and the first layer of petroleum asphalt or primer adhered to the surface of the steel pipe after tearing accounts for 100% of the tearing area to be qualified. The sampling ratio is 1% of the number of anti-corrosion pipe products produced on each shift that day, and not less than 1 pipe. Each pipe is tested at one point. If one pipe fails to meet the standard, it should be double checked. If one pipe still fails to meet the standard, the anti-corrosion pipe produced by this shift is considered unqualified.
5.1.6 Continuous integrity inspection of anti-corrosion coating: The continuous integrity inspection of anti-corrosion coating shall be carried out according to the provisions of Method B in "Test Method for Leakage Detection of Pipeline Anti-corrosion Layer" SY0063, using a high-voltage electric spark leak detector to inspect each anti-corrosion pipe. The leakage detection voltage shall comply with the provisions of Table 5.1.6.
Table 5.1.6 Leakage detection voltage
Anti-corrosion grade
Leakage detection voltage (kV)
5.2 Factory inspection of products
Ordinary grade
Reinforced grade
Extra-reinforced grade
5.2.1 Factory inspection of products shall be carried out on the basis of quality inspection during the production process. Each batch of products shall be inspected before leaving the factory. Unqualified products are strictly prohibited from leaving the factory.
5.2.2 The factory inspection of products shall comply with the following provisions: 1 Appearance inspection of the anti-corrosion layer: Inspection shall be carried out in accordance with the requirements specified in Article 5.1.3 of this standard. 2 Thickness inspection of the anti-corrosion layer: One anti-corrosion pipe shall be randomly inspected from each batch of 50 pipes, and if less than 50 pipes are counted as 50 pipes. The inspection method shall comply with the relevant provisions of Article 5.1.4 of this standard. The inspection results shall comply with the provisions of Table 3.0.1 of this standard. If the pipes are unqualified, the inspection shall be doubled. If the pipes are still unqualified, the batch of products shall be unqualified.
3 Continuous integrity inspection of the anti-corrosion layer: One anti-corrosion pipe shall be randomly inspected from each batch of 20 pipes, and if less than 20 pipes are counted as 20 pipes. The leakage detection voltage shall comply with the provisions of Table 5.1.6 of this standard. If the anti-corrosion pipes inspected are unqualified, the anti-corrosion pipes in this batch shall be inspected one by one. 6 Marking, stacking and transportation
6.0.1 For the anti-corrosion pipes that have passed the inspection, the steel pipe specifications, length, operating temperature and anti-corrosion factory number should be marked on the anti-corrosion layer, and various records should be filled in.
6.0.2 For the anti-corrosion pipes that have passed the inspection, the anti-corrosion grade should be marked, and the mark is the color band surrounding the anti-corrosion layer. The colorless band is the ordinary grade, the yellow band is the reinforced grade, and the red band is the extra reinforced grade. 6.0.3 The anti-corrosion pipes that have passed the inspection should be neatly stacked according to different categories and marked. The number of stacking layers shall be based on the anti-corrosion layer not being compressed. Soft materials should be placed on the bottom of the anti-corrosion pipe to avoid damaging the anti-corrosion layer. 6.0.4 When the anti-corrosion pipes leave the factory, they should be loaded after checking the material, diameter, wall thickness, anti-corrosion grade and operating temperature of the steel pipe according to the requirements of the construction site.
6.0.5 When loading, wide nylon belts or other special lifting tools should be used. It is strictly forbidden to use methods that damage the anti-corrosion layer, such as dropping, bumping, and prying. Soft pads should be placed between each layer of anti-corrosion pipes. When bundling, nylon belts or steel wire ropes with rubber hoses should be used. 6.0.6 When unloading pipes, special lifting tools should be used. It is strictly forbidden to use crowbars that damage the anti-corrosion layer to pry or roll and slide to unload. 7 Patching and repairing
7.0.1 After the butt weld of the pipeline has passed the appearance inspection and non-destructive testing, it should be patched. 808
SY/T 0420—1997
7.0.2 Before patching, the dirt, oil, frost at the patching site and the welding slag, burrs, etc. at the weld should be cleaned up, and the rust removal quality should reach the Sa2 or St3 level specified in GB/T8923.
7.0.3 The same anti-corrosion material, anti-corrosion grade and structure as the pipe body should be used for patching. When the two adjacent pipes have different anti-corrosion grades, the highest anti-corrosion grade shall prevail; but the design has special requirements for patching. 7.0.4 After patching, records should be made, and spot checks should be carried out according to the requirements specified in Articles 5.1.3, 5.1.4, 5.1.5 and 5.1.6 of this standard. If one of the ports is unqualified, double spot checks should be carried out; if one of the ports is still unqualified, the ports should be inspected. 7.0.5 The materials used for patching and the anti-corrosion grade and structure of the patched area should be the same as those of the pipe body. When patching, the dirt, dirt, frost and other attachments that affect the quality of the patching should be cleaned up first, and the wound area should be heated with a blowtorch to melt the asphalt, and petroleum asphalt and glass cloth should be applied in layers. Finally, the outer protective layer should be applied. The overlap width between the glass cloths and the outer protective layer should be greater than 50mm. When the damaged area is less than 100mm2, petroleum asphalt can be used for repair directly. 8 Inspection before and after backfilling of anti-corrosion pipeline trenches
8.0.1 Before the anti-corrosion pipeline is trenched, 100% electric spark leak detection should be carried out, and the leak detection voltage should comply with the provisions of Table 5.1.6 of this standard. It can only be trenched after passing the inspection.
8.0.2 The inspection of the anti-corrosion pipeline after backfilling should be carried out in accordance with the corresponding pipeline construction acceptance specifications. 9 Delivery data
9.0.1 After the pipeline anti-corrosion of the project is completed, the following technical data should be submitted: 1 Anti-corrosion pipe factory certificate (see Appendix D of this standard) and quality certificate; 2 Anti-corrosion material certificate, various test and inspection records; 3 Patching record;
4 Leakage detection and repair record;
5 Other technical data required by the construction unit. Appendix A
Determination of wax content in asphalt paste - adsorption method
A.0.1 Principle: Different hydrocarbons have different adsorption capacities on adsorbents. Generally speaking, strong adsorption makes desorption difficult; weak adsorption makes desorption easy. The oil in asphalt has weaker adsorption than colloid and asphaltene. Therefore, adsorbents can be used to separate the oil from colloid and asphaltene. The wax contained in the asphalt is dissolved in the oil, and then the oil is dewaxed with acetone toluene solution. Filter under low temperature conditions, recover the wax paste, and weigh it to constant weight to obtain the wax content.
A.0.2 The instrument shall meet the following requirements:
11/10000 analytical balance;
500mL fat extractor;
G2~G3 microporous filter funnel with a diameter of 40mm3
4-20℃, 120mm (diameter) × 120mm (length) semiconductor cold well; 510, 100, 500ml measuring cylinder;
250mL suction filter bottle;
7100mL beaker;
8250ml. Standard interface distillation glassware; 9 vacuum pump.
A.0.3 Reagents should meet the following requirements:
SY/T0420-1997
1100～200 mesh alumina or coarse-pore silica gel; 260～90℃ petroleum ether;
3 Benzene, acetone, toluene, ethanol.
The above reagents are all chemically pure.
A.0.4 Test steps should meet the following requirements: 1 Weigh 1.5～2g of sample (accurate to 0.0001g) and put it into a beaker, and dissolve it with 4~～5mL benzene. 2 Adsorbent: 30g of alumina burned at 500～600℃ for 12h or 30g of silica gel dried at 180～190℃ for 6h. Mix the solution prepared by the above method and the adsorbent evenly. 3 Put the beaker on a water bath and remove benzene at 80~～85℃ for 1h (should be done in a fume hood). Then move it into the cylinder made of filter paper, put the cylinder into the extraction cylinder of 0.5L fat extractor, cover the bottom of the filter with cotton, so that it always blocks the hole of the siphon. Then wash the beaker 3-5 times with petroleum ether with a boiling point of 60-90℃, pour the washing liquid into the extractor, so that the washing liquid is about half of the volume of the flask (add about 500mL in total). Let the installed instrument stand for 4-6 hours to complete the adsorption process of the sample by the adsorbent as much as possible, and then extract. After 5-6 hours of extraction, the flow rate of the petroleum ether condensate flowing down from the condenser end is 3-4 drops/s (adjust the water bath temperature to meet this requirement). When the petroleum ether condensate is completely colorless, stop the extraction. 4 Pour the extract (i.e., petroleum ether containing hydrocarbons) into a 250mL triangular beaker, connect the standard interface distillation glass instrument, and place the triangular beaker on a water bath to evaporate the petroleum ether. 5. Add 25 mL of a 3:2 mixture of toluene and acetone (volume ratio) into a conical flask to dissolve the residue in the flask, and pour the mixture into a 5C:ml colorimetric tube. Place the colorimetric tube, millipore filter funnel, glass rod, and cold wash solution (about 50 mL of a 3:2 mixture of toluene and acetone, which can be used for 3 samples) in a freezing bath in a cold well (ethanol is used as the freezing liquid), cool to -21°C, and keep it at this temperature for 1 hour. Then carefully stir the solution in the test tube and pour the solution into a millipore funnel for filtration. Wash the paraffin in the test tube with the cold wash solution 3 times (about 5 mL each time), and quickly filter with a vacuum pump. 6 After the filtration is completed, use 65~70℃ benzene (about 50mL) to dissolve the paraffin on the washing funnel and put it into the constant weight triangle beaker until there is no oil trace in the washing liquid. Distill the benzene on a water bath, dry the paraffin in a 105℃ constant temperature box for 30~60min, and weigh it to constant weight. A.0.5 The test results should be calculated as follows:
1 The percentage content of paraffin in asphalt is calculated according to formula (A.0.5-1). X= m=m2 ×100
Where: X-——paraffin percentage content (%); total weight of flask and paraffin (g);
m2--flask weight (g);
m — asphalt sample weight (g).
2 The error percentage is calculated according to (A.0.5-2). The error percentage is less than 10% for passing. Measured value
×100%
Error-
Average value
(A. 0. 5-1)
(A. 0.5-2 )
Appendix B
Test method for brittle temperature (cold resistance) of polyvinyl chloride industrial film B.0.1 The equipment should meet the following requirements: SY/T0420-1997
Brittle temperature test machine The striking speed is 1.97m/s±0.15m/s, and the striking radius is 1.57mm±0.12mm. B.0.2 The sample size should meet the following requirements: The sample length is 38mm±2mm, the width is 6mm±0.4mm, and the thickness is 2mm±0.2mm. B.0.3 This method is to strike the sample with a hammer of a certain energy and speed at low temperature, and calculate the temperature when the fracture rate is 50%. The determination method shall comply with the following provisions:
1 Clamp 10 samples in the clamp of the sample plate, add dry ice to the insulation tank containing industrial ethanol, and cool it to the required temperature. Place the sample plate with the sample in the refrigerant at the required temperature, keep it at this temperature for 5 minutes, hit all 10 samples within 1 minute, and then take out the sample plate.
2 Observe the fracture directly at room temperature, then change the temperature and repeat the above test steps until sufficient data is obtained. If the analytical method is used for calculation, the temperature interval must be equal, and the lowest fracture temperature and the highest fracture temperature of all fractures must be calculated. 3 Calculation method:
tso =t+At
Where: tu—-brittleness temperature of polyvinyl chloride industrial film (℃); -highest temperature of all fractures of the sample (℃); t--
△t temperature interval of the sample (℃);
S-the sum of the fracture percentages of the sample from the beginning of fracture to the complete fracture. Appendix C
Test method for heat aging (heat resistance) of polyvinyl chloride industrial film C.0.1 The equipment shall meet the following requirements: Blast heat aging test box, with a heating power of 20kW and a turntable speed of 11r/min. C.0.2 The sample size shall meet the following requirements: dumbbell-shaped sample length 110mm±1mm, width 6.5mm±0.5mm, thickness 2mm±0.1mm (B.0.3)
C.0.3 The determination method shall meet the following requirements: The sample is heated at 101℃±1℃ for 168h and then taken out. After being placed at room temperature for 24h, the tensile strength and elongation at break are tested. The arithmetic mean of the three samples is taken, and the aging performance is calculated according to the following formula. Wu Zhong: (--Performance retention rate (%); tensile strength or elongation at break after test; -- tensile strength or elongation at break before test. b.×100
SY/T0420--1997
Appendix D
Product Certificate
The format of the product certificate shall comply with the provisions of Table D. D. 0. 1
Table D Product Certificate
Steel Pipe Specifications
Product Name
Asphalt Anticorrosive Layer Steel Pipe
Production Date:
Pipe Diameter × Wall Thickness
Year Month Day
Inspector:
(Anticorrosive Factory Name)
No.:
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