Asme V UT - (chap 13 / III E) Flashcards
What is the UT limitations?
200F, and applicable to material that will propagate a constant velocity
What technique is used?
Pulse-echo
Formula?
T=vt/2
T=thickness
v=velocity
t=transit time
velocity can be found in ASTM 494, instrument will obtain the transit time to calculate the material thickness.
How to verify effectivity of UT measurement?
Using 2 size of reference blocks,
What are the display element?
A scan display, meter or digital displayer
What is the 4 items that need to be subject to contractual agreement?
- Personnel Qualification
- Qualification of NDE agencies
- Procedure and techniques
- Surface preparation
What are the flaw detectors readouts?
- A scan display readouts -
- numeric readouts
- Thickness readouts
What is flaw detectors with A scan display readouts?
displayed in time/amplitude. Thickness determination are made by reading the distance between the zero corrected initial pulse and first returned echo (back reflection) or between multiple back reflection echoes on a STANDARDIZED BASED LINE.
Base line should be adjusted for the desired thickness increments
What is flaw detectors with numeric readouts?
combination of pulse ultrasound flaw detection instrument with A scan display and additional circuitry that provides digital thickness info.
What is flaw detectors with thickness readout
modified version of pulse echo instrument. The elapse time between the initial pulse and first echo or between multiple echoes is converted into a meter or digital readout.
When do we use UT?
- evaluation of tank shell for CR
- evaluation of tank bottom (MFL is used with UT)
- tank roof evaluation (if corroded to avg thickness of less than 0.09” in any 100in^2 area)
- evaluation of thickness of components - like reinforcement plates, nozzle necks, cover plates.
