In accordance with the requirements of this standard, thermal adhesive polymer anticorrosive coating (barrier coating) is used in the factory. For the purpose of this standard, the term polymer coating is intended to include thermoplastic and thermosetting coating materials, which are used to coat the internal and external surfaces of two valves and fittings,
This standard covers the application fields of the following services:
（1） Factory applied coatings and related coatings are used for maintenance.
（2） Ductile iron, gray iron, malleable iron, steel and copper alloy substrates.
（3） Valves, pipe fittings and their components and related equipment. Contact with water and waste water up to 50c.
Process and test items of applying for wras certification for zinc powder coating and epoxy coating:
To apply for the test of BS 6920, the first thing to ask is the service conditions of the product (cold water, hot water)
Do not fill in the test data
Test time 8-9 weeks (chemical test takes time)
Wras test items of zinc powder coating:
1. Odor & flavor of water test (BS 6920-2.2): odor and taste of water test;
This test is to check the effect of the smell and taste of water on the materials. It takes 14 days.
2. Appearance of water (BS 6920-2.3)
This test is to check the effect of water color and turbidity on the material, which takes 14 days.
3. Growth of aquatic microorganisms (BS 6920-2.4)
The purpose of this test is to show whether the proof material will support the growth of microorganisms in water by measuring the absorption of dissolved oxygen. This test to
7-8 weeks less. If the test material is cementitious, an additional control procedure is required - using this procedure will
4. The extraction of substances that may be of concern to public health
Extraction of substances for public health:
This is a toxicity test using a monkey kidney (green monkey kidney cell) cell line. The sample is immersed in water and then cultured with tissue
Test the toxicity of water. The test will take at least 7 days to complete.
5. The extraction of metals
This test is to prove whether the material will filter out metal substances in water, and it will take 4 weeks to complete.
Information required for certification: application form (including the cover composition form), instruction manual (including the information of official points such as the applicant's name, website, contact number, etc.), power of attorney (between the applicant and US), BS6920 test report (designated agency)