This standard specifies an experimental method for measuring the chemical stability of pipeline anticorrosion coatings. This standard is applicable to the evaluation of the corrosion resistance of pipeline anticorrosion coatings immersed in chemical media of various concentrations or inferred soil pollutants. SY/T 0039-1997 Test method for chemical stability of pipeline anticorrosion coatingsSY/T0039-1997 Standard download decompression password: www.bzxz.net

1 Scope
Petroleum and Natural Gas Industry Standard of the People's Republic of China Test Method for Chemical Stability of Pipeline Anticorrosion Coatings Approval Department: China National Petroleum Corporation Approval Date: 1997-12-31
Implementation Date: 1998-07-01
This standard specifies a test method for measuring the chemical stability of pipeline anticorrosion coatings. SY/T 0039—1997
Replaces SYJ39---1989
This standard is applicable to the evaluation of the corrosion resistance of pipeline anticorrosion coatings immersed in chemical media of various concentrations or inferred soil pollutants. 2 Reference Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards. SY/T0037--1997 Cathodic disbonding test method for pipeline anticorrosion coating SY0062--1992 Test method for penetration of pipeline anticorrosion coating (blunt rod method) SY0063-1992 Test method for leak detection of pipeline anticorrosion coating SY 0066-1992
2 Non-destructive measurement method for thickness of pipeline anticorrosion coating (magnetic method) 3 Definitions
This standard adopts the following definitions.
3.1 Discoloration
The color change of anticorrosion caused by the action of chemical reagents, etc. 3.2 Sweiling
The phenomenon of softening and swelling caused by the penetration of solvent molecules into the interior of the anticorrosion coating. 3.3 Bubble
Bubble with obvious outline below the outer surface of the anticorrosion coating. 3.4 Blister
Bubble with obvious protrusion on the outer surface of the anticorrosion coating. 3.5 Crack
Cracks produced on the outer surface or inside of the anti-corrosion layer due to stress, external impact or environmental conditions. 4 Overview and significance of the method
4.1 This method is to immerse the test piece in the gas and liquid phases of the relevant chemical medium in a closed container, and regularly observe the changes in the anti-corrosion layer. Then, the changes in the adhesion properties of the anti-corrosion layer should be measured according to the lifting method specified in SY/T0037. The changes in the mechanical properties or adhesion properties of the anti-corrosion layer can also be measured by needle penetration test or other tests according to the provisions of SY0062. 4.2 The test conditions should consider the immersion method and duration, reagents, system temperature, area exposed above and below the liquid surface, and other performance factors selected for the specific test.
4.3 The results obtained from the test are used to exclude the most unsuitable anti-corrosion materials or to derive the corrosion resistance order of different anti-corrosion layers in a certain medium. 862
5 Instruments
5.1 Instruments used in this test
a) Magnetic thickness gauge: measuring range 1μm~20mm, accuracy is 2% of each range; b) Spark leak detector: leak detection voltage 900~20000V. 5.2 Test container
SY/T0039—1997
5.2.1 A transparent closed container, the size of which can completely accommodate the test piece and be sufficient to expose it to the gas and liquid phases of the reagent. A glass wide-mouth bottle with a capacity of 2500mL is recommended. 5.2.2 Rubber stopper for plugging the wide-mouth bottle and rubber stopper for sealing the test piece. 5.2.3 When using volatile solvents or when gas may be generated during the test, a positive pressure exhaust device, such as a water seal, should be installed. 6 Test piece
6.1 Test piece specifications and production
6.1.1 The test piece should be a representative pipe section with an anti-corrosion layer that meets the product quality standards. The anti-corrosion layer should have no obvious cracks or defects. 6.1.2 If the container recommended in 5.2.1 is used, the length of the test piece (including the exposed part of the rubber plug at the end of the pipe) should not exceed 180mm. The pipe lengths of the same group of test pieces should be the same, accurate to ±2mm. The outer diameter of the test piece should not exceed 65mm. 6.1.3 Measure the average thickness of the anti-corrosion layer of each test piece in accordance with the provisions of SY0066. 6.1.4 Use an electric spark leak detector to detect leaks on the test piece in accordance with the provisions of SY0063, and no leaks are required. 6.1.5 Both ends of the pipe are plugged with rubber plugs and sealed with epoxy-based paint to make a test piece without man-made defect holes. 6.1.6 Make a test piece with artificial defect holes. Drill one artificial defect hole on the surface of the test piece at 1/4 of the distance from the pipe end as shown in Figure 1. The two defect holes should be located on the same axis of the pipe. The cone of the drill bit enters the steel pipe and the edge of the cone contacts the surface of the steel pipe. Be careful not to penetrate the pipe wall. The diameter of the drill hole should not be less than 3 times the thickness of the anti-corrosion layer and not less than 6mm. Rubber stopperwww.bzxz.net
Gas phase space
Wide-mouth bottle
Artificial defect hole
Rubber stopper
Rubber stopper
A--Test piece length; B-1/4 test piece length
Figure 1 Schematic diagram of chemical immersion test container
6.2 Number of test pieces
6.2.1 The number of basic immersion test pieces for each anti-corrosion layer in a medium is 12, and there are 6 test pieces with artificial defect holes and 6 test pieces without artificial defect holes.
6.2.2 For each anti-corrosion layer test piece, 1 to 2 test pieces without artificial defect holes (not impregnated) should be retained for comparison. 863
SY/T 0039—1997
6.2.3 When it is necessary to conduct mechanical property tests or other tests before and after impregnation, additional test pieces should be prepared. 7 Chemical medium
The selected medium should be those substances expected to be contained in the environment. The test media are as follows: 7.1
a) acetic acid: 5%;
b) acetone;
c) carbon disulfide;
d) gasoline;
e) hydrochloric acid: 10%;
f) kerosene;
g) saturated lime water;
h) methanol;
i) ketone;
j) nitric acid: 10%;
sodium carbonate solution: 20%;
sodium chloride solution: 10%;
sodium hydroxide solution: 10%;
sulphuric acid: 30%;
o) toluene;
p) transformer oil;
trichloroethylene;
other selected environmental media.
7.2 Chemical reagents shall be industrial or chemically pure. Freshly distilled water shall be used to prepare the solution. 8 Test steps
8.1 Place a test piece vertically in each test container as shown in Figure 1. 8.2 Slowly inject the selected medium to 1/2 of the length of the test piece. 8.3 Cover the test container tightly to prevent the medium from volatilizing and contaminating. The liquid level should be kept at the initial position during the test. 8.4 During the test, the test container and the test piece shall be kept at the predetermined test temperature, and the fluctuation range shall not exceed ±5°C. 8.5 After immersion for 30, 60, and 90 days, take out two test pieces with and without artificial defect holes from each medium, rinse all test pieces taken out from acid, alkali or other solutions with tap water, and wipe them dry with soft and clean cotton cloth or tissue paper. Test pieces taken out from volatile solvents (such as gasoline, alcohol) do not need to be rinsed before wiping dry. 8.6 During the period of immersion of the specimen, before removal, at the moment of removal and 2 hours after removal, observe and record the appearance of the specimen, such as fading of gloss, enlargement of mesh, decomposition, discoloration, softening, swelling, damage, dark bubbles, blistering, cracking, dissolution, etc. 8.7 Each artificial defect hole should be peeled off according to the provisions of 9.4 of SY/T0037-1997 to check whether the adhesion of the anti-corrosion layer has decreased during the test.
8.8 The penetration test of the anti-corrosion layer before and after immersion can be carried out according to the provisions of SY0062. If other performance comparison tests are carried out, they should be carried out according to the relevant standard test methods.
9 Safety measures
Necessary safety and health regulations should be considered and established before using this standard to avoid direct contact between operators and reagents. Toxic vapors should be excluded, and combustion and explosion should be prevented according to the hazardous properties of the chemical reagents used. 10 Test report
10.1 The test report should include the following: a) Complete identification information of the test piece, including the name of the anti-corrosion layer, the anti-corrosion layer grade, the manufacturer, the production process, the production date, etc.; b)
Test temperature;
Medium description;
Immersion time,
Initial average thickness of the anti-corrosion layer;
The diameter (mm) and area (mm2) of the artificial defect hole; The appearance change of the test piece after immersion;
h) The immersion liquid phase area and gas phase area (mm2); i) The name of the tester and technical reviewer and the test date. 10.2 The format of the test report is shown in Appendix A (Appendix to the standard). Appendix A
(Appendix to the standard)
Format of the test report on chemical stability of pipeline anticorrosion coating Test report on chemical stability of pipeline anticorrosion coating Name of anticorrosion coating
Test temperature
Change after immersion
Tester
Grade of anticorrosion coating
Start and end time of immersion
Test piece number
Average thickness of anticorrosion coating
Length of steel pipe
(mm）
Outer diameter of steel pipe
Liquid phase immersion area||tt ||(mm2）
Gas phase infiltration area
(mm2）
Diameter of artificial defect hole
Peeling area
Technical reviewer
Production process
Test cycle
In liquid phase
In gas phase
In liquid phase
In gas phase
Manufacturer
Medium description
SY/T0039—1997
Production date
Year, month
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