Vibrations issues

[ww2i]

What are the most underrated causes of vibration issues in rotating equipment from an operations perspective?

[tiror]

From an operations perspective, some of the worst vibration problems are not caused by bad machinery — they are caused by process conditions quietly pushing the machine outside its stable operating envelope. A lot of vibration investigations stay too mechanical-focused (alignment, balancing, bearings), while the actual trigger is process or operational behavior.
Some of the those causes include the following:
1. Operating Too Far From BEP
2. Two-Phase Flow
3. Poor Warm-Up / Thermal Stabilization
4. Minimum Flow Recycle Systems Creating Instability
5. Pipe Strain Introduced During Operation
6. Control Valve Hunting
There are other many but when vibrations appear, it is best to ask;
When vibration appears, ask:
a. Did process conditions change?
b. Did throughput change?
c. Did tank/source change?
d. Any valve hunting?
e. Any recent maintenance?
f. Any control loop tuning changes?
g. Is recycle active?
h. Is machine near minimum flow?
i. Any temperature transient?
j. Any intermittent cavitation sounds?
k. Any startup procedure deviation?

[sys1]

I was just thinking about badd transmitters which can indirectly create vibration through faulty flow indication, incorrect level, bad pressure reading, and drifting temperature sensor.
Operators then unknowingly push machine into low-flow region, cavitation, surge margin loss, and unstable hydraulics.
The machine becomes the victim of bad process information.

[tiror]

A very practical addition sys1.
Those kind of indicators, faulty ones should be picked up at a very early stage, responsibility falls with Operations.

I was just thinking about badd transmitters which can indirectly create vibration through faulty flow indication, incorrect level, bad pressure reading, and drifting temperature sensor.
Operators then unknowingly push machine into low-flow region, cavitation, surge margin loss, and unstable hydraulics.
The machine becomes the victim of bad process information.

[ivani1]

Best

From an operations perspective, some of the worst vibration problems are not caused by bad machinery — they are caused by process conditions quietly pushing the machine outside its stable operating envelope. A lot of vibration investigations stay too mechanical-focused (alignment, balancing, bearings), while the actual trigger is process or operational behavior.
Some of the those causes include the following:
1. Operating Too Far From BEP
2. Two-Phase Flow
3. Poor Warm-Up / Thermal Stabilization
4. Minimum Flow Recycle Systems Creating Instability
5. Pipe Strain Introduced During Operation
6. Control Valve Hunting
There are other many but when vibrations appear, it is best to ask;
When vibration appears, ask:
a. Did process conditions change?
b. Did throughput change?
c. Did tank/source change?
d. Any valve hunting?
e. Any recent maintenance?
f. Any control loop tuning changes?
g. Is recycle active?
h. Is machine near minimum flow?
i. Any temperature transient?
j. Any intermittent cavitation sounds?
k. Any startup procedure deviation?