DL/T 694-1999 in English

This guide specifies the technological process and evaluation standards for the ultrasonic inspection of high-temperature tight bolts.
This guide is applicable to the ultrasonic inspection of the high-temperature tight bolts with diameter larger than or equal to M32 used for steam cylinders, steam ports, various valves and steam pipe flanges.
The ultrasonic inspection of other tight bolts also may be made reference to this guide.

Foreword I
1 Scope
2 Normative References
3 Flaw Detection Personnel
4 Flaw Detector and Probe
5 Test Block
6 Preparation before Flaw Detection
7 Flaw Detection
8 Evaluation
9 Record Report
Appendix A (Normative) Special Test Blocks Used for Ultrasonic Inspection of High-temperature Tight Bolts
Appendix B (Normative) Portable Reference Blocks Used for Ultrasonic Inspection of High-temperature Tight Bolts
Appendix C (Normative) Ultrasonic Inspection Report of High-temperature Tight Bolts