Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard was proposed by the China Petroleum and Chemical Industry Association.
This standard is under the jurisdiction of National Technical Committee of Paints & Pigments for Standardization (SAC/TC5).
Anticorrosive coatings for metal surface under insulation
1 Scope
This standard specifies the requirements, test method, inspection rules, marking, packaging and storage of anticorrosive coatings for metal surface under insulation.
This standard is applicable to anticorrosive coatings and supporting system for external surface such as metal storage tanks, pipelines and equipment under insulation.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the normative document (including any amendments) applies.
GB/T 1725-2007 Paints Varnishes and Plastics - Determination of Non-volatile-matter Content
GB/T 1728-1979 Methods of test for drying time of coatings of paints and putties
GB/T 1732-1993 Determination of impact resistance of film
GB/T 1733-1993 Determination of resistance to water of films
GB/T 1766-2008 Paints and varnishes - Rating schemes of degradation of coats
GB/T 1771-2007 Paints and varnishes - Determination of resistance to neutral salt spray (fog)
GB/T 3186 Paints, varnishes and raw materials for paints and varnishes - Sampling
GB/T 5210-2006 Paints and varnishes - Pull-off test for adhesion
GB/T 6682-2008 Water for analytical laboratory use - Specification and test methods
GB/T 6742-2007 Paints and varnishes - Bend test (cylindrical mandrel)
GB/T 6750-2007 Paints and varnishes - Determination of density - Pyknometer method
GB/T 8170-2008 Rules of rounding off for numerical values & expression and judgment of limiting values
GB/T 8923.1-2011 Preparation of steel substrates before application of paints and related products - Visual assessment of surface cleanliness - Part 1: Rust grades and preparation grades of uncoated steel substrates and of steel substrates after overall removal of previous coatings
GB/T 9271 Paints and varnishes - Standard panels for testing
GB/T 9278 Temperatures and humidities for conditioning and testing of paint specimens.
GB/T 9286-1998 Paints and varnishes - Cross cut test for films
GB/T 9750 Marks for package of coating products
GB/T 9793-2012 Thermal spraying - Metallic and other inorganic coating - Zinc, aluminum and their alloys
GB/T 10699-1998 Calcium silicate insulation products
GB/T 13288.1-2008 Preparation of steel substrates before application of paints and related products - Surface roughness characteristics of blast-cleaned substrates - Part 1: Specifications and definitions for ISO surface profile comparators for the assessment of abrasive blast-cleaned surfaces
GB/T 13452.2-2008 Paints and varnishes - Determination of film thickness
GB/T 13491 General rule for packing of coatings
GB/T 13893-2008 Paints and varnishes - Determination of resistance to humidity - Continuous condensation
GB/T 16995-1997 Determination of gel time of thermosetting powder coatings at a given temperature
GB/T 20624.1-2006 Paints and varnishes - Rapid-deformation(impact resistance) tests - Part 1: Falling-weight test large-area indenter
GB/T 30789.2-2014 Paints and varnishes - Evaluation of degradation of coatings - Designation of quantity and size of defects, and of intensity of uniform changes in appearance - Part 2: Assessment of degree of blistering
GB/T 30789.3-2014 Paints and varnishes - Evaluation of degradation of coatings - Designation of quantity and size of defects, and of intensity of uniform changes in appearance - Part 3: Assessment of degree of rusting
GB/T 30789.4-2015 Paints and varnishes - Evaluation of degradation of coatings - Designation of quantity and size of defects, and of intensity of uniform changes in appearance - Part 4: Assessment of degree of cracking
GB/T 30789.5-2015 Paints and varnishes - Evaluation of degradation of coatings - Designation of quantity and size of defects, and of intensity of uniform changes in appearance - Part 5: Assessment of degree of flaking
GB/T 30789.8-2015 Paints and varnishes - Evaluation of degradation of coatings - Designation of quantity and size of defects, and of intensity of uniform changes in appearance - Part 8: Assessment of degree of delamination and corrosion around a scribe or other artificial defect
GB/T 30790.6-2014 Paints and varnishes - Corrosion protection of steel structures by protective paint systems - Part 6: Laboratory performance test methods
GB/T 31416-2015 Paints and varnishes - Determination of the pot - life of multicomponent coating systems - Preparation and conditioning of samples and guidelines for testing
HG/T 4337-2012 Solventless liquid epoxy paints for steel water pipelines
JG/T 25-1999 Determination for freeze - Thaw resistance of film of building coatings
JC/T 618-2005 Methods of chemical analysis of thermal insulation materials for leachable chloride, fluoride, silicate and sodium lons
3 Requirements
3.1 Design requirements for coating supporting system
Unless otherwise specified, the design of the coating supporting system shall meet the requirements of Table 1.
Table 1 Design requirements for coating supporting system
Usage temperature range
℃ Supporting coating Recommended thickness of dry film
μm Recommended number of coating layers
-45~120 1 Primer Epoxy resin coating 100~150 1~2
Finish paint Epoxy resin coating 100~150 1~2
2 Primer High solid epoxy resin coating 100~200 1~2
Finish paint High solid epoxy resin coating 100~200 1~2
3 Finish paint Solventless epoxy resin coating 200~500 1
4 Finish paint Sintered epoxy coating 250~350 1
5 Primer Thermal sprayer apparatus (TSA) 250~375 1
Sealing paint a Epoxy resin coating About 40 1
-45~204 1 Primer Epoxy-phenol coating b 100~150 1
Finish paint Epoxy-phenol coating b 100~150 1
2 Primer Thermal sprayer aluminum (TSA) 250~375 1
Sealing paint a Epoxy-phenol coating b 25~40 1
-45~400 1 Finish paint Modified silicone coating 200~250 1~2
150~540 1 c Primer Silicone coating 25~50 1~2
Finish paint Silicone coating 25~50 1~2
2 Primer Thermal sprayer aluminum (TSA) 250~375 1
Sealing paint c Silicone coating 25~40 1
-45~650 1 Finish paint Inorganic copolymer coating or inert polymer coating 200~300 1~2
-196~60 d 1 Primer Epoxy resin coating 100~150 1~2
Finish paint Epoxy resin coating 100~150 1~2
2 Primer High solid epoxy resin coating 100~200 1~2
Finish paint High solid epoxy resin coating 100~200 1~2
3 Finish paint Solventless epoxy resin coating 200~500 1
4 Finish paint Inorganic copolymer coating or inert polymer coating 200~300 1~2
-196~150 d 1 Primer Epoxy-phenol coating b 100~150 1
Finish paint Epoxy-phenol coating b 100~150 1
2 Finish paint Inorganic copolymer coating or inert polymer coating 200~300 1~2
a Sealing paint can be selected based on actual needs, it is not necessary for coating.
b It may also be called phenolic epoxy coating.
c The coating supporting system is used for stainless steel substrates and is not recommended for carbon steel substrates.
d When the storage and transport medium is liquefied natural gas (LNG) , the equipment temperature is approximately -180℃.
3.2 Performance requirements of coating supporting system
According to the different usage temperature ranges, the performance of the coating supporting system shall meet the requirements of Table 2. The performance of the coating supporting system after the temperature variation cyclic resistant test shall meet the requirements of Table 3.
Table 2 Performance requirements of coating supporting system
Usage temperature range
℃ Adhesion
(Pull method)a
MPa Cross cut test b
Level Water resistance Temperature variation cyclic resistance c
(5 times) Salt spray resistance Condensed water resistance Cyclic corrosion test
-45~120 ≥5 — Pass for 1000 h Pass Pass for 720 h Pass for 480 h —
-45~204 Pass for 720 h Pass or agreed
-45~400 — ≤2 Pass
150~540 Pass for 120 h Pass for 240 h —
-45~650 Pass for 720 h Pass for 720 h Pass for 480 h
-196~60 ≥5 —
-196~150
a All coating system except for silicone coating, modified silicone coating, inorganic copolymer coating or inert polymer coating shall be tested.
b Only the coating systems containing silicone coating, modified silicone coating, inorganic copolymer coating or emotional polymer coating shall be tested.
c The test may be carried out according to the agreed temperature range by agreement of two parties.
Table 3 Performance of the coating supporting system after the temperature variation cyclic resistant test
Usage temperature range
℃ Adhesion (pull method) a
MPa Cross cut test b
Level Salt spray resistance Condensed water resistance
-45~120 ≥2.5 — Pass for 1000 h Pass for 480 h
-45~204
-45~400 — ≤2
150~540 ≤3 Pass for 240 h —
-45~650 ≤2 Pass for 1440 h Pass for 480 h
-196~60 ≥2.5
-196~150
a All coating system except for silicone coating, modified silicone coating, inorganic copolymer coating or inert polymer coating shall be tested.
b Only the coating system containing silicone coating, modified silicone coating, inorganic copolymer coating or emotional polymer coating shall be tested.
3.3 Performance requirements of coating product
3.3.1 Performance requirements of epoxy resin coating product
The performance of epoxy resin coating product shall meet the requirements of Table 4.
Table 4 Performance requirements of epoxy resin coating product
Item Technical index
Epoxy resin coating High solid epoxy resin coating Epoxy-phenol coating Solventless epoxy resin coating
Condition in container No caked mass and with uniform state after mixed and stirred
Content of non-volatile matter/% ≥ 55 80 70 98
Density/(g/mL) Agreed value ± 0.05 —
Applicable period/h To be agreed
Drying time/h Surface drying ≤ 8 12
Hard drying ≤ 24 24
Coating appearance Normal
Bending test/mm ≤ 3 —
Bending resistance (1.5°) — No crack on coating film
Impact resistance /cm ≥ 40 —
Impact strength (3 J) — No cracking or peeling
Chloride ion content a/(mg/kg) ≤ 30
a Test is required when the substrate is stainless steel.
3.3.2 Performance requirements of sintered epoxy coating product
The performance of sintered epoxy coating product shall meet the requirements of Table 5.
Table 5 Performance requirements of sintered epoxy coating product
Item Technical index
Condition in container Tiny uniform powder state
Gel time/s Agreed value ± 20 %
Bending resistance (1.5°) No crack on coating film
Impact strength (3 J) No cracking or peeling
3.3.3 Performance requirements of high-temperature resistance coating product
The performance of high-temperature resistance coating product shall meet the requirements of Table 6.
Table 6 Performance requirements of high-temperature resistance coating product
Item Technical index
Silicone coating Modified silicone coating, inorganic copolymer coating, inert polymer coating
Condition in container No caked mass and with uniform state after mixed and stirred
Content of non-volatile matter/% ≥ 45 60
Density/(g/mL) Agreed value ± 0.05 —
Drying time/h Surface drying ≤ 2 4
Hard drying ≤ 24 24
Coating appearance Normal
Bending test/mm ≤ 3 —
Impact resistance /cm ≥ 40
Large area impact/J ≥ — 4
Chloride ion content a/(mg/kg) ≤ 30
a Test is required when the substrate is stainless steel.
3.3.4 Performance requirements of thermal sprayer aluminum (TSA) products
Thermal sprayer aluminum (TSA) products shall meet the requirements of GB/T 9793-2012.
4 Test methods
4.1 Sampling
Product is sampled according to the requirements of GB/T 3186 or the agreed method. The sampling quantity shall be determined as required by inspection.
4.2 Test environment
Unless otherwise specified, the conditioning of the test plate and temperatures and humidities of the test shall meet the requirements of GB/T 9278.
4.3 Preparation of test template
4.3.1 Substrate and substrate processing
Unless otherwise agreed, substrate shall be selected in accordance with Tables 7 and 8. Unless otherwise agreed, the material and treatment of the tinplate and steel plate for test shall meet the requirements of GB/T 9271, and the treatment of the stainless steel plate shall meet the treatment method of solvent or aqueous cleaning agent specified in GB/T 9271. Sandblasted steel plate and steel tube (including round tube and square tube) for test are subjected to blast cleaning, the surface cleanliness shall reach the level Sa2 1/2 specified in GB/T 8923.1-2011, the surface roughness shall reach "(G)" level specified in GB/T 13288.1-2008. Sandblasted stainless steel plate and stainless steel tube (including round tube and square tube) for test are subjected to blast cleaning, the surface roughness shall reach "(G)" level specified in GB/T 13288.1-2008. The agreed material type and treatment method of substrate shall be noted in the inspection report.
4.3.2 Preparation of specimen
The specimen is prepared after uniformly mixed according to the component ratio specified by the product and placed for the specified curing time. Single constituent coatings are not required to curing.
4.3.3 Requirements for plate preparation
4.3.3.1 Requirements for plate preparation of coating supporting system performance
Unless otherwise agreed, the test template and specimen are prepared according to Table 7. The measurement of coating thickness shall be carried out according to the requirements of GB/T 13452.2-2008.
When measuring the dry film thickness on the sandblasted steel plate, take no less than 2 readings from the upper, middle and bottom of the test plate and must at least 10 mm from the edge when reading. Remove any abnormally high or low readings and take the mean of 6 readings.
When measuring the dry film thickness on the sandblasted round tube, mark 4 points (with cruciform after connection) at the bottom of the round tube. Their angles on the circular hole are 0°, 90°, 180°, 270° respectively. Take the 4 points as start points, read numbers every 50 mm along the longitudinal direction of the tube, carry out 44 readings and take the mean of them.
When measuring the dry film thickness on the sandblasted square tube, take no less than 2 readings from the four corners and the middle position of the plane of the single coating system and must at least 10 mm from the edge when reading, take the mean of 10 readings; take no less than 2 readings at each end and middle position of the corner, and must at least 10 mm from the edge when reading. Take the mean of the 6 readings. The 4 surfaces and 4 corners of the square tube need to be tested.
Foreword i
1 Scope
2 Normative references
3 Requirements
3.1 Design requirements for coating supporting system
3.2 Performance requirements of coating supporting system
3.3 Performance requirements of coating product
4 Test methods
4.1 Sampling
4.2 Test environment
4.3 Preparation of test template
4.4 Operation method
5 Inspection rules
5.1 Inspection classification
5.2 Judgment of test results
6 Marking, packaging and storage
6.1 Marking
6.2 Packaging
6.3 Storage
Annex A (Normative) Multi-phase transverse cyclic corrosion test
Annex B (Normative) Vertical cyclic corrosion test