Failure Investigation of a Corrosion Leak in a C77 Block and Tubing Bonnet in a Chemical Injection System – A Case History

2021 ◽  
Author(s):  
Valdir De Souza ◽  
Eugenia Marinou ◽  
Andrew Legge ◽  
Vicky Nwafor
Keyword(s):  
Case History ◽  
Tap Water ◽  
Dissimilar Materials ◽  
Injection System ◽  
Scale Inhibitor ◽  
Root Cause ◽  
Failure Investigation ◽  
System Integrity ◽  
Oxygen Ingress ◽  
Corrosion Mechanisms

Abstract This paper presents a case history outlining the investigation performed to evaluate the causes of failure between a C77 block and tubing bonnet line, used for delivering scale inhibitor to a production well. The data review indicated that the failure occurred as a result of synergistic corrosion effects, including incompatibility between the scale inhibitor chemical and the metallurgies of the block (13Cr SS) and tubing (carbon steel). The analysis showed that while each of the relevant corrosion mechanisms (oxygen corrosion, galvanic and localised corrosion) may not be the root cause for the failure individually, in combination they proved detrimental to system integrity. The study also highlighted that while chemical inhibitor compatibility testing with appropriate flow-wetted metallurgies is common practice, the environment and configuration used for testing is not always representative of the field conditions or specific process operations (e.g., oxygen ingress due to unblanketed tanks, presence of dissimilar materials). In the present case, for example, the most significant oxygen sources were found to be the dissolved oxygen in the tap water used to mix the scale inhibitor to make up the final formulation; and the glycol blended into the product to give it ‘winterised’ properties. Lastly, the paper summarises the recommendations that were put forth to address the issue, such as evaluation of different metallurgies, a more suitable scale inhibitor and implementation of process monitoring, especially of oxygen levels.

Failure Localization in a Multistage S-Band Power Amplifier

2016 ◽  
Author(s):  
Clarence Rebello ◽  
Ted Kolasa ◽  
Parag Modi
Keyword(s):  
Output Power ◽  
Power Amplifier ◽  
Fault Tree ◽  
Root Cause ◽  
Failure Investigation ◽  
Band Power ◽  
Cause Of Failure ◽  
Design Materials ◽  
Board Level ◽  
Failure Localization

Abstract During the search for the root cause of a board level failure, all aspects of the product must be revisited and investigated. These aspects encompass design, materials, and workmanship. In this discussion, the failure investigation involved an S-Band Power Amplifier assembly exhibiting abnormally low RF output power where initial troubleshooting did not provide a clear cause of failure. A detailed fault tree drove investigations that narrowed the focus to a few possible root causes. However, as the investigation progressed, multiple contributors were eventually discovered, some that were not initially considered.

Failure Investigation of 1st Stage Buckets From Frame 3002, 10 MW Gas Turbine Unit

2011 ◽  
Author(s):  
Girish M. Shejale ◽  
David Ross
Keyword(s):  
Gas Turbine ◽  
Test Results ◽  
High Carbon ◽  
High Carbon Content ◽  
Metallurgical Investigation ◽  
Root Cause ◽  
Failure Investigation ◽  
Surface Failure ◽  
Grain Boundary Embrittlement ◽  
Industrial Gas Turbine

The 1st stage buckets in Frame 3002, 10 MW industrial gas turbine experienced premature failures. The buckets failed unexpectedly much earlier than the designed bucket life. Bucket material is Inconel 738, with platinum-aluminized coating on the surface. Failure investigation of the buckets was performed to know the root cause of the failure. The failure investigation primarily comprised of metallurgical investigation. The results of the metallurgical investigation were co-related with the unit operational history. This paper provides an overview of 1st stage buckets investigation. The metallurgical investigation performed concluded prime failure mechanism due to high carbon content of bucket material and improper heat treatment. The bucket coating was initially damaged during the first loading and fracture occurred due to grain boundary embrittlement in short span of service. The metallurgical tests performed included Visual inspection, Scanning Electron Microscopy (SEM), Energy Dispersive Analysis of X-ray (EDS), Chemical analysis, Tensile test and Hardness survey. The test results, discussions and conclusions are presented in this paper.

Failure Investigation of a Leak in the Offshore Water Injection System

2021 ◽  
pp. 153-172
Author(s):  
Torben Lund Skovhus ◽  
Øystein Bjaanes ◽  
Bjarte Lillebø ◽  
Jo-Inge Lilleengen
Keyword(s):  
Water Injection ◽  
Injection System ◽  
Offshore Water ◽  
Failure Investigation

Failure Investigation on Rusty Mesh Strainer of Petrochemical Plant

2013 ◽  
Vol 795 ◽  
pp. 488-491 ◽  
Author(s):  
Shaiful Rizam Shamsudin ◽  
Mohd Harun ◽  
Mohd Arif Anuar Mohd Salleh ◽  
Hafizal Yazid ◽  
Mohd Noor Mazlee
Keyword(s):  
Human Error ◽  
Good Condition ◽  
Wire Mesh ◽  
Petrochemical Plant ◽  
Root Cause ◽  
Failure Investigation ◽  
Error Factor ◽  
The Wire ◽  
The Impact ◽  
Filter Mesh

The wire material of filter mesh is made of 304 grade stainless steel. The failure to run properly was due to the impact of burst and torn. The client also expects that the failure was due to corrosion problems. A visual inspection on the strainer mesh was found covered by brownish rust layers and some scratches at the damaged area. The rusty wire mesh that was washed with pickling acid showed a clean and smooth surface. Energy dispersive spectroscopy (EDS) examination of the rusty wire mesh surface indicated that it was only normal oxide precipitates. Thus, it's proven that there were no signs of severe corrosion attack on the failed sample. SEM micrographs showed the unidirectional scratch effects exist in the damaged area. The fractography study was found there was a typical ductile structure on the fracture surface of the wire. It is proven that the wire mesh was actually still in good condition and has not experienced any embrittlement problems as if it exposed to any corrosive environment. The root cause of the failure is shown by the effect of scratches in which it is usually caused by a mechanical forceful push by a hard object or in other words, it is caused by human error factor.

Root Cause Analysis of A Piston Pump Failure: A Case History

2000 ◽  
Author(s):  
C. E. Fey ◽  
R. Goebel ◽  
G. E. Totten ◽  
R. J. Bishop
Keyword(s):  
Case History ◽  
Root Cause Analysis ◽  
Piston Pump ◽  
Cause Analysis ◽  
Pump Failure ◽  
Root Cause

Failure Investigation of Products and Components in Metal Forming Industry: Root Cause Analysis and Process-Based Approach

2020 ◽  
Vol 20 (1) ◽  
pp. 106-114
Author(s):  
Sofia Papadopoulou ◽  
Athanasios Vazdirvanidis ◽  
Anagnostis Toulfatzis ◽  
Andreas Rikos ◽  
George Pantazopoulos
Keyword(s):  
Metal Forming ◽  
Root Cause Analysis ◽  
Cause Analysis ◽  
Root Cause ◽  
Failure Investigation
Sign in / Sign up

Export Citation Format

Share Document