API 571 Erosion/Erosion-Corrosion

The removal of surface material by impacting material is what?

The removal of a materials protective scale by impacting material is called?

Which of the following is NOT a primary factor contributing to erosion?
A) Velocity of impacting particles
B) Impact angle (angle that impacting particles strike metal)
C) Corrosiveness of the environment
D) Density of impacting particles
E) Size of impacting particles

Which of the following is NOT a primary factor contributing to Erosion-Corrosion?
A) Corrosiveness of the environment
B) Tensile strength of the metal
C) Impact angle (angle that impacting particles strike metal)
D) Velocity of impacting particles

A prime location for Erosion is:
A) in catalyst piping
B) downstream of a gate valve
C) in superheated steam piping

In the Crude Unit, piping and vessels may have high metal loss from Erosion-Corrosion if the unit is exposed to:
A) hydrogen
B) naphthenic acid
C) water
D) low strength caustic

Erosion or Erosion-corrosion usually appears as:
A) random grooving
B) directional cracks
C) Directional pits, grooves, or waves
D) random pitting

A 6 NPS carbon steel line is experiencing Erosion-Corrosion. A reasonable solution would be to:
A) reduce the velocity by lowering the Unit throughput by 50%
B) increase the line size to 10 NPS
C) remove all elbows and replace with long bent pipe
D) overlay the inside of the pipe with Stellite or another hard alloy.