This test method is an accelerated test method, suitable for determining the water permeability of metal pipeline anticorrosion coatings. SY/T 0064-2000 Test method for water permeability of pipeline anticorrosion coatings SY/T0064-2000 Standard download decompression password: www.bzxz.net
This test method is an accelerated test method, suitable for determining the water permeability of metal pipeline anticorrosion coatings.

ICs 75.200,25.220.40
Registration No.: 8176—2001
Petroleum and Natural Gas Industry Standard of the People's Republic of ChinaSY/T 00642000
Test method for water penetration into pipeline coatings2000-12-25Release
State Administration of Petroleum and Chemical Industry
2001-06～01Implementation
SY/T0064--2000
Cited Standards
Reagents and Materials
Equipment and Instruments
Test Specimen Preparation
Test Procedures
Test Report
Precision
SY/T 0064—2000
According to the arrangement of the China National Petroleum Corporation's Quality and Safety Letter [2000 No. 31 Notice on Issuing the 2000 Petroleum and Natural Gas Industry Standard Formulation and Revision Plan], the Pipeline Bureau Staff College is responsible for revising SY/T 00G4-92 "Test Method for Water Permeability of Pipeline Anti-corrosion Layers". The revised standard is equivalent to ASTMG987 (confirmed in 1998) "Standard Test Method for Water Permeability of Pipeline Anti-corrosion Layers. This test method is an accelerated test method that detects the water penetration process by measuring the changes in the capacitance value and loss factor of the anti-corrosion layer material. The revised writing format of this standard complies with the relevant provisions of GB/T1.1—1993\. This standard revision is consistent with SY/『 0064-92 has slight changes in the following chapters: a) "Foreword" has been added; b) Chapter 1 "General Principles" of the original standard has been changed to "Scope"; d) Chapter 2 and Chapter 3 of the original standard have been combined into Chapter 3 "Source" of this standard; e) Chapter 4 "Reagents and Materials" has been added; f) Chapter 9 "Precision" of the original standard has been changed to Chapter 10 "Precision" of this standard; and the additional instructions for the source standard have been removed. This standard will take effect from , and replaces SY/T0064-92. This standard was proposed by China National Petroleum Corporation: This standard was drafted by the Oil and Gas and Pipeline Construction Design Professional Standardization Committee. The drafting unit of this standard: Pipeline Bureau Staff College, the main drafters of this standard, Lin Rongfang, Lin Jianma, Lu Niu Haijuan, Liu Yang. This standard was first issued in June 1992. This is the first revision. This standard is entrusted to the Pipeline Bureau Staff College for interpretation. 1 Scope
Petroleum and Natural Gas Industry Standard of the People's Republic of China Test method for water penetration into pipeline anti-corrosion layer
SY/T 0064-2000
Replaces SYT 0064.92
Standard tcst method for water penetration into pipeline coatigsThis test method is an accelerated test method, which is suitable for determining the water permeability of the anti-corrosion layer of metal pipes. 2 Cited standards
The clauses contained in the following standards constitute the clauses of this standard through reference in this standard. When this standard is published, the versions shown are valid: All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards: SY/T0066--1999 Non-destructive measurement method of the thickness of the anti-corrosion layer of steel pipes (magnetic method) 3 Principle
3.1 The specimen is immersed in the electrolyte, and the metal pipe, anti-corrosion layer and electrolyte form a coaxial capacitor. During the test period, the dielectric constant changes due to water seepage in the anti-corrosion layer. The water seepage depth of the anti-corrosion layer is determined by measuring the changes in capacitance and loss factor during the test period. 3.2 The degradation of the performance of the anti-corrosion layer is closely related to its water content. When the test data is expressed as a time-related value. It will reflect the degradation of the performance of the anti-corrosion layer material. The rate is related to the life of the insulating anticorrosion layer. For a given material, the water permeability test can provide useful technical information for determining the optimal degree of the anticorrosion layer. 4 Reagents and materials
Electrolyte: It is made of rice water and the following industrial-grade anhydrous salts, that is, sodium chloride, sodium sulfate, and sodium carbonate, each accounting for 1% by weight. You can also add 30g of sodium chloride per liter of water:
5 Equipment and instruments
5.1 Test tank: What are the characteristics of the test piece that can accommodate the test piece? The size of the non-metal container (see Figure 1) shall meet the following requirements. 5.1.1 The test piece shall be suspended vertically, and the distance between the test piece and the test wall and the bottom of the tank shall not be less than 25mm. 5.1.2 The distance between the test pieces and between the test piece and the anode shall be 25-40mm, and the distance between the resistor and each test piece shall be equal. 5.1.3 The test tank shall have sufficient depth, and the immersion depth of the test piece in the electrolyte shall comply with the provisions of 6.5: Note: It is recommended to use a 300mm×300mm glass cylinder as the test tank. The nominal diameter of the test piece applicable to this tank is 26.7 mm or (x).3 The length of the test piece shall not exceed 30 mm. 5.2 Test tank cover: The cover for hanging the test piece and the anode shall be made of materials with low dielectric constant and have a liquid injection hole. 5.3 Power supply: A power supply that can provide low pulse DC voltage shall be used. The power supply shall be able to keep the voltage between the test piece and the anode at 6V ± 0.1V. 5.4 Connecting wire: The wire connecting the anode and the test piece shall be a sheet-insulated soft-shielded control cable. The cable model is KVVRF-! ×0).516. The anode joint shall be sealed and located above the electrolyte. When using the bridge measurement, the connecting wire should be easily disconnected from the positive pole: the simple method is to use an insulating pin socket 5.5 Capacitance bridge: The equivalent capacitance of the test piece and the anti-corrosion layer loss factor should be determined using a low-voltage resistance type AC bridge. Its characteristics are as follows:
Approved by the State Administration of Petroleum and Chemical Industry on 2000-12-25 and implemented on 2001-06-01
Support pin
Screen drum net
Liquid injection hole
a) Oscillation frequency: 1kHz±2%;
SY/T 0064—2000
Sealing ring
Electrolyte
Anti-corrosion layer
Sealing cap
Test piece support plate and cover
Figure 1 Schematic diagram of test device
b) Capacitance measurement range: (1-1100) PF±1%: c) Capacitance measurement sensitivity; 0.5pF;
d) Loss factor measurement range: 0.001~1.0 (at 1kHz): e) Loss factor measurement sensitivity: 0.001 (at 1kHz). 5.6 Measurement circuit: The connection between the test tank and the capacitance bridge is shown in Figure 2. The connecting wires and the test tank should be shielded, and the bridge housing should be grounded to prevent external electric field interference.
5.7 Thickness gauge: It should comply with the relevant provisions of SY/T0066. 5.8 Anode: Made of 1Cr18Ni9Ti stainless steel with a diameter of 5mm. A 50mm long thread is made at the upper end to tighten the connecting wire. The length of the anode should be such that its lower end is flush with the top surface of the specimen sealing cap. 6 Specimen preparation
6.1 Specimens of appropriate diameter and length can be used, and the specimens should be free of cracks and obvious defects. When the test trough recommended in Note 5.1 is used, the specimen diameter is generally 26.7mm or 60.3mm, and the length does not exceed 300mm. Its structure is shown in Figure 3. The metal surface pretreatment and anti-corrosion coating coating process of the specimen should be the same as those of the industrially produced anti-corrosion layer pipe. 6.2 The lower end of the specimen should be sealed with an insulating plug, and the lower end sealing cap and upper sealing ring should be cast. In order to reduce the end capacitance effect, the thickness of the sealing cap and sealing ring should be controlled between 13 and 19mm. 6.3 The materials used for the sealing cap and sealing ring should be firmly bonded to the anti-corrosion layer and have low water absorption; the dielectric constant is between 2 and 6, and it is an elastic solid at room temperature. It can be sealed with epoxy adhesive (the mass ratio of epoxy resin, dibutyl phthalate and ethylenediamine is 100:5:2) or ethylene-vinyl acetate copolymer (EVA) hot melt adhesive with good toughness after curing, and then cast with paraffin mixture paraffin and rosin with a mass ratio of 100: (40-50).
Test piece 2
Anti-corrosion layer
Aluminum or tin box
SY/T0064—2000
Test piece 1
Shielding net
Electric bridge
Electrolyte
Figure 2 Schematic diagram of the connection between the test device and the bridge Wiring boltwwW.bzxz.Net
Support pin
Sealing ring
Anti-corrosion layer
Sealing wax
Figure 3 Test piece
6.3.1 The method for making the sealing cap is as follows:
a) Process the wiring holes and pin holes on the upper end of the specimen, wipe the surface of the anti-corrosion layer at the lower end sealing cap and the upper sealing ring, and seal the lower end of the specimen with an insulating plug;
b) Dip the melted ethylene-vinyl acetate copolymer (EVA) hot melt adhesive (220℃) or use epoxy adhesive with good toughness after curing to seal the lower end of the specimen, and then hang the specimen vertically; c) Use aluminum foil to make a mold of appropriate size, place it under the specimen, adjust the relative position of the specimen and the mold, so that the thickness of the sealing cap meets the requirements of 6.2;
d) Heat the paraffin and rosin to dehydrate (160℃), cool to about 80C, and cast them into the lower end sealing cap. 3
6.3.2 The method for making the upper sealing ring is as follows: SY/1 0064—2000
a) Use aluminum foil to make a mold of appropriate size and fix it at the upper sealing position so that the thickness of the sealing ring meets the requirements of 6.2: b) Heat the paraffin and rosin to dehydrate (160℃) and cool to about 80℃, and cast them into the upper sealing ring; ) Seal the anti-corrosion layer above the sealing ring with the same material as the sealing cap. 7 Test steps
7.1 Measure the thickness of the anti-corrosion layer ton according to the relevant provisions of SY/T0066 7.2 Measure the length of the anti-corrosion layer L3 between the sealing pad and the sealing ring 7.3 Fix the test piece and the anode on the support plate, put them in the test bottle, and connect the circuit. Check whether the distance between the test piece and the anode meets the requirements of 5.! According to the regulations, slowly inject electrolyte until it just submerges the upper edge of the lower sealing cap, and measure the sealing cap capacitance C7.4 Continue to inject electrolyte until the liquid reaches the lower edge of the sealing ring, and immediately measure the initial capacitance value (. And the initial loss factor IDF7.5 Connect the test piece to the negative pole of the power supply, and the anode to the positive pole of the power supply. During the entire test cycle, ensure that each test piece is powered. Add water regularly to keep the electrolyte at the lower edge of the sealing ring. 7.6 During the test cycle, regularly measure the series capacitance of the unsoaked test piece (and the loss factor 1F7.6.1 Temporarily disconnect the test piece and the anode from the power supply, and check the electrolyte level in the test bottle: Connect the capacitance bridge, measure the capacitance value C and the loss factor DF
7.6.2 Substitute the measured capacitance value into the formula given in 8.2 to calculate the water seepage depth t7.6.3 The measurement period is determined by the rate of decline of the performance of the anti-corrosion layer. Generally, it is measured once a period of time. When the capacitance changes rapidly, it is necessary to measure every time. Note: The capacitance and loss factor of some anti-corrosion layers are 1/1 at first. They reach a balance state within 6 to 9 months (the capacitance and loss factor of some anti-corrosion layers do not have this balance state): the capacitance and loss factor increase, indicating that the anti-corrosion layer is about to fail. When the loss factor reaches 1.0, the specimen is considered to have failed.
7.7 After the test, the electrolytic film shall not be used again. 8 Calculation
8.1 Calculate the dielectric constant Kn of the anti-corrosion layer according to formula (1): (c- C)n.(2tu 4d)/d)
武K—dielectric constant of anti-corrosion layer:
Cn——initial electric penetration of anti-corrosion room, F:
C——capacitance of sealing cap. pF:
d—outer diameter of steel ridge, m
1o—thickness of anti-corrosion layer, mm;
immersion length of anti-separation layer, rmm
N-—take .0556.
8.2Substitute the K calculated by formula (1) and the (value measured again into the following formula, and the water seepage depth of the anti-corrosion layer can be calculated as tr = tt
1- (d/2).(em - 1)
M =N. Ku- LAC.-C)
Where: ——Water penetration depth of anti-corrosion layer, mmC—Internal capacitance of test piece, pF
t——Thickness of unpenetrated anti-corrosion layer, mml,
9Test report
The test report should include the following contents.
9.1Complete description of the test piece;
a) Name and technical standard number of anti-corrosion layer;
b) Pipe diameter and length;
|) Source, production date and product batch; d) Maximum, minimum and average thickness of anti-corrosion layer: e) Test start and end time:
f) Other relevant information,
9. 2 Test data:
SY/T0064—2000
\) The value and polarity of the point current voltage applied to the test piece during the test; b) Test number;
c) Water seepage depth within the test period:
d) The starting and ending position of the anti-corrosion layer loss factor; e) Plot the relationship between the anti-separation layer water seepage depth and time using a rectangular coordinate system: f) Plot the relationship between the anti-separation layer loss flash number and time using a semi-logarithmic coordinate system: 10 Precision
Repeatability: Under the condition of alternating conditions, the allowable deviation of the water seepage depth and loss factor of the same test piece from their average value is 25 tires:2 Test data:
SY/T0064—2000
\) The value and polarity of the point current voltage applied to the test piece during the test; b) Test number;
c) Water seepage depth within the test period:
d) The starting and ending position of the anti-corrosion layer loss factor; e) Plot the relationship between the anti-separation layer water seepage depth and time using a rectangular coordinate system: f) Plot the relationship between the anti-separation layer loss flash number and time using a semi-logarithmic coordinate system: 10 Precision
Repeatability: Under the condition of alternating conditions, the allowable deviation of the water seepage depth and loss factor of the same test piece from their average value is 25 tires:2 Test data:
SY/T0064—2000
\) The value and polarity of the point current voltage applied to the test piece during the test; b) Test number;
c) Water seepage depth within the test period:
d) The starting and ending position of the anti-corrosion layer loss factor; e) Plot the relationship between the anti-separation layer water seepage depth and time using a rectangular coordinate system: f) Plot the relationship between the anti-separation layer loss flash number and time using a semi-logarithmic coordinate system: 10 Precision
Repeatability: Under the condition of alternating conditions, the allowable deviation of the water seepage depth and loss factor of the same test piece from their average value is 25 tires:
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