[도장후검사] Discontinuity(Holiday) Testing

Discontinuity(Holiday) Testing

 

1. 요약 정리

• Coating Film 500μm 이하 : Low-voltage wet sponge testing (NACE RP0188)

• Coating Film 500μm 초과 : High-voltage spark testing (NACE RP0188)

• Test Voltage : ASTM G62 계산식 활용 (위 NACE Code 역시 활용 가능)

1) Coating Thickness  ≤  1.016 mm (40 mils)

2) Coating Thickness  ≥  1.041 mm (41 mils)

• 합격기준 : No holiday

• 불합격 시 : Backfilling 전 Repair 후 Re-examine

 

2. 관련 코드

• ASME B31.1 Power Piping

   Appendix IV. Corrosion control for power piping systems

   IV-2.2 Protective Coating

   IV-2.2.3 (첫 번째 문장) 파이프 코팅은 Holiday detector를 활용하여 육안으로 검사되어야 한다. 

• ASTM G62 Test Methods for Holiday Detection in Pipeline Coating

   6. Apparatus

   6.1 Low-Voltage Holiday Detector

   6.2 High-Voltage Holiday Detector

• NACE SP0188 Discontinuity (Holiday) Testing of Protective Coating

• NACE SP0274 High Voltage Electrical Inspection of Pipeline Coatings

• NACE SP0490 Holiday Detection of Fusion Bonded Epoxy

3. 참조 사진 

---

출처 : My Brain + 배관정복 + Google Search