المعنى والاستخدام
5.1 الطريقة أ — Method A describes a rapid and safe method for determining whether there are pinholes, voids, or metal particles protruding from the coating. لكن, this method does not detect any thin spots in the coating. This method will determine if there are any serious defects in the film pipe coating.
5.2 الطريقة ب — Method B describes a method for determining whether there are pinholes, voids, or metal particles protruding from the coating and thin spots in the pipe coating. The method can be used to verify minimum coating thickness as well as voids in quality control applications.
ASTM G62-2022 Standard Test Method for Detection of Leakage Points of Pipe Coatings
يتراوح
1.1 These test methods cover equipment and procedures for detecting leaks in pipe-type coatings.
1.2 Method A is designed to detect defects such as holes and voids in thin film coatings of a thickness of 0.025 كمية العينة المطلوبة لكل منها 0.254 مم (1 كمية العينة المطلوبة لكل منها 10 ميل) using ordinary tap water and an applied voltage of less than 100 V DC. If the wetting agent is used with water, it is effective against films up to 0.508 مم (20 ميل) thick. لكن, it should be noted that this method does not detect thin spots in the coating. Due to the relatively low voltage, this can be considered non-destructive testing.
1.3 Method B is used to detect defects such as pinholes and voids in pipeline coatings; But because of the higher voltage applied, it can also be used to detect thin spots in coatings. The method can be used for pipe coatings of any thickness and uses 900 كمية العينة المطلوبة لكل منها 20 000 V DC voltage. 2 This method is considered destructive because the high pressure involved usually destroys the coating at thin points.
1.4 The value of the International System of Units with three significant decimals shall prevail. القيم الواردة بين قوسين هي للإشارة فقط.
1.5 لا يهدف هذا المعيار إلى معالجة الكل, لو اي, مخاوف السلامة المرتبطة باستخدامه. تقع على عاتق مستخدمي هذا المعيار مسؤولية إنشاء السلامة المناسبة, الممارسات الصحية والبيئية وتحديد مدى انطباق القيود التنظيمية قبل الاستخدام.
1.6 This international standard is based on internationally recognized standardization principles established in the Decision on International Standards, Guidelines and Recommended Principles issued by the WTO Committee on Technical Barriers to Trade (TBT).