Ultrasonic Straight Beam and Utrasonic Shear Wave in API 581 1

[etsen]

In Table 9-7 of API 581, "Ultrasonic Straight Beam" means ultrasonic thickness measurement and "Ultrasonic Shear Wave" nondestructive test for cracking etc.? Thanks

 

[gr2vessels]

The ultrasonic testing method called Ultrasonic Straight Beam is mostly suitable for thickness testing, including sub-surface blisters detection. The Ultrasonic Shear Wave method is more suitable for detecting the surface and subsurface imperfections, like cracks, just as you noted. Also, refer to ASTM for various specifications for these ultrasonic testing methods and acceptance standards.
cheers,
gr2vessels