scholarly journals Leakage Investigation on a Fired Heater Tube of a Petroleum Refinery due to Carburization

Metalurgi ◽  
2019 ◽  
Vol 34 (2) ◽  
pp. 91
Author(s):  
D.N. Adnyana
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Dispersive Spectroscopy ◽  
Energy Dispersive ◽  
Petroleum Processing ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Process Fluid ◽  
Heater Tube ◽  
Scanning Electron

The fired heater of a petroleum processing refinery leaks in one of the convection tubes. The tube is made of ASTM A-106 Gr.B. Process fluid in the tube is xylene with a design pressure of 15.8 kg/cm²g and design temperature of 299 °C (at the inlet) and 405 °C (at the outlet). This study aims to determine the type and causes and the mechanism of leakage in the tube. A number of tests have been carried out including visual inspection and  macroscopic analysis, chemical analysis, metallographic and hardness testing, and SEM (scanning electron microscopy) analysis which is equipped with EDS (energy dispersive spectroscopy). The results obtained showed that the leak that occurred in the convection tube was caused by carburization and metal dusting. Carburization occurs in the inner walls of the tube that experience some localized overheating due to the formation of coke deposits. AbstrakDapur pemanas pada sebuah kilang pengolahan minyak bumi mengalami kebocoran pada salah satu pipa konveksi. Pipa tersebut terbuat dari baja karbon rendah jenis ASTM A-106 Gr.B. Cairan proses di dalam pipa adalah xylene dengan tekanan desain 15,8 kg/cm²g dan suhu desain yaitu 299 °C (pada saluran masuk) dan 405 °C (pada saluran keluar). Penelitian ini bertujuan untuk menentukan jenis dan faktor penyebab serta mekanisme terjadi kebocoran pada pipa tersebut. Sejumlah pengujian telah dilakukan meliputi pemeriksaan visual dan makroskopik, analisa kimia, pengujian metalografi dan kekerasan, serta analisa SEM (scanning electron microscopy) yang dilengkapi dengan EDS (energy dispersive spectroscopy). Hasil penelitian yang diperoleh menunjukkan bahwa kebocoran yang terjadi pada pipa konveksi disebabkan oleh karburisasi dan pembentukan debu/serbuk logam. Karburisasi terjadi pada dinding bagian dalam pipa yang mengalami panas berlebih secara lokal akibat terbentuknya endapan kokas.

Pengaruh implantasi ion tin (Titanium Nitrida) terhadap sifat mekanis baja VCL 140

2010 ◽  
Vol 8 (1) ◽  
pp. 753
Author(s):  
Muhammad Muhammad
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Dispersive Spectroscopy ◽  
Energy Dispersive ◽  
Scanning Electron

Implantasi ion dapat meningkatkan sifat mekanik seperti kekerasan bahan yang akan digunakan untuk komponen dan peralatan proses manufaktur. Implantasi ion dipengaruhi oleh jenis ion dopan, waktu dan energi yang digunakan. Penelitian ini dilakukan untuk mengetahui pengaruh energi dan waktu implantasi ion titanium nitrida terhadap kekerasan dan struktur mikro pada baja VCL 140. Implantasi dilakukan pada arus berkas tetap 10 yA. Variasi waktu 60, 70, 80, 90, 100, 110, 120 menit, energi 75 keV dan variasi energi 15, 30, 45, 60, 75, 90 dan 100 keV dengan waktu implantasi 100 menit dilakukan untuk mendapatkan kekerasan optimum. Uji Kekerasan menggunakan metode Vickers dengan beban 10 gram dan waktu 10 detik. Topografi dari lapisan TIN diamati menggunakan scanning electron microscopy (SEM) dan komposisi kimia dari lapisan TIN dianalisa menggunakan energy dispersive spectroscopy (EDS).Kata kunci : Implantasi ion, VCL 140, kekerasan

Apicoectomy and Scanning Electron Microscopy Analysis of an Implant Infected by Apical (Retrograde) Peri-implantitis: A Case Letter

2018 ◽  
Vol 44 (4) ◽  
pp. 287-291
Author(s):  
Rafael Manfro ◽  
Gislaine Felipe Garcia ◽  
Marcelo Carlos Bortoluzzi ◽  
Vinicius Fabris ◽  
Atais Bacchi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Scanning Electron Microscopy Analysis ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Scanning Electron

scholarly journals Use of Scanning Electron Microscopy and Energy-Dispersive Spectroscopy to Correlate the Arrangement of Starch with Resistance to Maize Weevil (Coleoptera: Curculionidae) in Sorghum Grain

2011 ◽  
Vol 17 (S2) ◽  
pp. 250-251
Author(s):  
M Pendleton ◽  
B Pendleton ◽  
E Ellis ◽  
G Peterson ◽  
F Chito ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Dispersive Spectroscopy ◽  
Energy Dispersive ◽  
Maize Weevil ◽  
Sorghum Grain ◽  
Scanning Electron

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

scholarly journals Residual smear layer after root canal instrumentation by using Niti, M-Wire and CM-Wire instruments: A scanning electron microscopy analysis

2018 ◽  
Vol 12 (03) ◽  
pp. 403-409 ◽  
Author(s):  
Ricardo Machado ◽  
Daniel Comparin ◽  
Eduardo Donato Eing Engelke Back ◽  
Lucas da Fonseca Roberti Garcia ◽  
Luiz Rômulo Alberton
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Root Canal ◽  
Smear Layer ◽  
Significant Difference ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Root Canal Instrumentation ◽  
Reciprocating Systems ◽  
Scanning Electron

ABSTRACT Objective: The purpose of this study was to compare the amount of residual smear layer after root canal instrumentation by using Ni-Ti, M-Wire, and CM-Wire instruments. Materials and Methods: Seventy-two mandibular incisors were randomly divided into six groups according to the system used: WaveOne (WO), Reciproc (RP), Unicone (UC), ProTaper Next (PN), Mtwo (MT), and HyFlex (HF). Afterward, the specimens were cleaved in the mesiodistal and buccolingual direction for analysis by scanning electron microscopy. Results: Considering both directions and root canal thirds, there was no difference between HF, MT, and PN. RP, UC, and WO presented a significant difference between the directions, and the cervical third showed a significantly smaller quantity of residual smear layer compared with the apical third. When the systems were compared among them, there was a significant difference only between RP and WO. Conclusions: Residual smear layer observed after instrumentation with the different systems was similar, except for quantities between the reciprocating systems.

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