2 replies to this topic

[Parco12345]

We have a sundyne pump at Crude Distillation Unit. The pump was opened due to seal leakage issues. Internal Inspection revealed damage to impeller and Inducer.

Following are the process conditions

Serive : Stripped Water

pH : 10.5 to 11.0 on average

Rated Flow: 37 m3/h

Suction Presssure : ~ 0.5 kg/cm2.G

Discharge Pressure : 31 kg/cm2

Flow variation: 15 ~ 38 m3/h

Normal Flow : 32 m3/h

Design Minimum Flow : 7.2 m3/h

Stripped Water Temp : 65 ~ 70 C ( Temperature remained 80 ~ 85 C for 4 to 5 months as well)

Material of Impeller : ss316L

Pictures are attached for reference.

Can any one help me sort our the root cause of the problem and remedial actions:

 

 

 

 

 

 

 

 

 

 

` 

Attached Files

•  Impeller3.jpg   423.16KB   4 downloads
•  Inducer2.jpg   384.29KB   2 downloads

[Bobby Strain]

It looks like corrosion to me. You should review the material selection, and change to a suitable material. Your metallurgist should know.

 

Bobby

[sheiko]

Hello
In addition to the above comment, I believe you should investigate the cause of seal leakage as this may be correlated with the impeller damage.
Check for NPSHA, and if the pump were operating on or below its curve....
Also, vendor usually recommend to operate between 80% and 110% of rated flowrate (30-40 m3/h in your case).
Do you use ARC valve, control valve or restriction orifice to ensure the pump miniflow? Is it reliable?

Edited by sheiko, 14 July 2017 - 12:33 AM.