Menu
Search
Filters
Close
Menu

51318-10871-Failure of Light Naphtha Discharge Pump in a 2-Stage Overhead System of Condensate Splitting Unit

Picture for Failure of Light Naphtha Discharge Pump in a 2-Stage Overhead System of Condensate Splitting Unit
Available for download

Recently, a light naphtha discharge pump (made of UNS J91150 casing and impeller) malfunctioned, which caused severe damage to the impeller. Details of the failure analysis will be presented and discussed.

Product Number: 51318-10871-SG
Author: Gyutae Park / Jinseok Seo / Majid Abbasi / Yunjo Ro
Publication Date: 2018
Industry: Corrosion Monitoring and Control
$0.00
$20.00
$20.00

Corrosion of overhead system in the distillation unit has been a chronic and unresolved issue even with the injection of neutralizer and corrosion inhibitors. Recently, a light naphtha discharge pump (made of UNS J91150 casing and impeller) malfunctioned, which caused severe damage to the impeller. It was subsequently realized that, prior to the malfunction of the impeller, the pH of the water at the second overhead accumulator unexpectedly dropped to 2.6 with simultaneous increase of Fe concentration. Preliminary analysis of the impeller revealed that it had failed from a combination of corrosion and cavitation. To understand the origin of corrosion, extensive water chemistry analysis was performed, which revealed the presence of corrosive species such as sulfate and nitrate ions, presumably from the flue gas, which would have caused pH to drop. Autoclave corrosion tests also revealed that these species would cause significant corrosion of UNS S41000 which is similar to UNS J91150 used in the pump. In-depth electron microscope study (i.e., SEM, EBSD) on corrosion scale and damaged impeller surface was performed to confirm that the damage mechanism was corrosion-induced cavitation. Details of the analysis will be presented and discussed.

Key words: overhead corrosion, naphtha, sulfate, nitrate, cavitation of UNS J91150

Corrosion of overhead system in the distillation unit has been a chronic and unresolved issue even with the injection of neutralizer and corrosion inhibitors. Recently, a light naphtha discharge pump (made of UNS J91150 casing and impeller) malfunctioned, which caused severe damage to the impeller. It was subsequently realized that, prior to the malfunction of the impeller, the pH of the water at the second overhead accumulator unexpectedly dropped to 2.6 with simultaneous increase of Fe concentration. Preliminary analysis of the impeller revealed that it had failed from a combination of corrosion and cavitation. To understand the origin of corrosion, extensive water chemistry analysis was performed, which revealed the presence of corrosive species such as sulfate and nitrate ions, presumably from the flue gas, which would have caused pH to drop. Autoclave corrosion tests also revealed that these species would cause significant corrosion of UNS S41000 which is similar to UNS J91150 used in the pump. In-depth electron microscope study (i.e., SEM, EBSD) on corrosion scale and damaged impeller surface was performed to confirm that the damage mechanism was corrosion-induced cavitation. Details of the analysis will be presented and discussed.

Key words: overhead corrosion, naphtha, sulfate, nitrate, cavitation of UNS J91150

Product tags
Also Purchased
Picture for High Temperature Alloys Failures in the Petrochemical Furnaces. Mitigation and Prevention
Available for download

51318-10877-High Temperature Alloys Failures in the Petrochemical Furnaces. Mitigation and Prevention

Product Number: 51318-10877-SG
Author: Ali H. AlShawaf / Manabendra K. Maity
Publication Date: 2018
$20.00

This paper explains the most common damage mechanisms of high temperature alloys in radiant section such as creep/carburization, thermal fatigue/carburization, and thermal shock.

 
Picture for A Functional Test Program for Assessing Internal Corrosion Monitoring Probes’ Performance
Available for download

51318-10868-A Functional Test Program for Assessing Internal Corrosion Monitoring Probes’ Performance

Product Number: 51318-10868-SG
Author: Abdul Razzaq Al-Shamari / Amer Jarragh / Surya Prakash / S.Mathusoothanan
Publication Date: 2018
$20.00

A functional test program designed with laboratory conditions suitable for the field corrosive situations and screening the performance of ER and LPR probe types for further application in the field.

 
Picture for Failure Analysis for a Piggable Pipeline Through ICDA Methodology
Available for download

51318-10869-Failure Analysis for a Piggable Pipeline Through ICDA Methodology

Product Number: 51318-10869-SG
Author: Abdul Razzaq Al-Shamari / Amer Jarragh / Ashish Khera / Shabbir Safri / Abdul Salam / Patrick J. Teevens
Publication Date: 2018
$20.00

In May, 2014, a total of five leaks were reported in two 34” (863 mm) diameter pipelines (both only 5 years in operation) due to internal corrosion. This paper describes all the activities that have been carried out determine the root cause.
Categories
Industry
Recently viewed
Popular tags
View all

Association for Materials Protection and Performance

© AMPP All Rights Reserved.
Membership Terms of Content Use
Contact Customer Support