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) Impact angle (angle that impacting particles strike metal)
B) Velocity of impacting particles
C) Size of impacting particles
D) Corrosiveness of the environment
E) Density of impacting particles

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

A prime location for Erosion is:
A) in superheated steam piping
B) downstream of a gate valve
C) in catalyst 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) directional cracks
B) random pitting
C) Directional pits, grooves, or waves
D) random grooving

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