Hangers & Snubbers

Question 1

Describe types of strain and movements

Answer 1

Weight, process of fluid, system components, pressure , vibration

Question 2

What do hangers do

Answer 2

Support system piping
Prevent damage by compensation of strains and movements

Question 3

Describe types of hangers

Answer 3

Flexible- allows vertical movements due to thermal expansion
Variable support - varies with spring deflection and the spring scale
Constant support- provides support throughout the full range of expansion and contraction
Rigid - no vertical movement
Snubbers- a special type of hanger, used for more complex systems to slow the movement of the piping
Mechanical and hydraulic

Question 4

Explain the basic operation of mechanical snubbers

Answer 4

Restrain the movements during a seismic event, ex= unit trips
Limit acceleration - prevent water hammer

Question 5

Hydraulic snubber

Answer 5

2 on each RCP and each SG

Question 6

Failure modes for snubbers & hangers

Answer 6

After severe service ( earthquake or water hammer)
Damaged seals
Loss of hydraulic fluid
Improper assembled
Overheating due to welding
Becoming dirty or corroded offer time
Improper lubrication