Studi Laju Korosi Internal Pipa Baja Api 5L Grade B Berdasarkan Metode Pengukuran Metal Loss Dengan Ultrasonic Dan Polarisasi Resistance Dengan Variasi Konsentrasi Klorida

2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Supriyadi Supriyadi
Keyword(s):  
Analysis Of Variance ◽  
Metal Loss ◽  
Thickness Meter ◽  
Ultrasonic Thickness

Pipa  penyalur  minyak  umumnya  menggunakan  material  baja  karbon.  Salah  satu  masalah  besar  dalam penggunaan material tersebut yang berkaitan dengan korosi yaitu terjadinya kebocoran akibat adanya pengaruh konsentrasi ion klorida yang terlarut dalam media air sehingga lingkungan bersifat korosif (asam). Oleh karena itu sebagai upaya untuk mengatasi masalah tersebut perlu diketahui besaran laju korosi material baja karbon tersebut. Dalam penelitian ini dilakukan perbandingan antara laju korosi yang diperoleh dari metode pengujian linear polarisasi resistance dan pengukuran metal loss dengan peralatan ultrasonic thickness meter. Output dari kedua metode tersebut selanjutnya diperoleh hubungan laju korosi melalui analysis of variance dengan menggunakan software. Studi pengaruh kadar klorida dilakukan untuk mengetahui korosi internal pipa baja karbon API 5L Grade B yang digunakan sebagai pipa penyalur minyak di lapangan. Metode pengujian polarisasi resistance dilakukan dalam media larutan air formasi NaCl 1%, 2% dan 3.5%. Laju korosi internal pipa baja karbon API 5L Grade B cenderung meningkat seiring dengan meningkatnya konsentrasi klorida dalam media larutan. Penelitian ini juga menunjukkan bahwa pipa baja karbon API 5L Grade B memiliki ketahanan korosi yang cukup pada fluida dengan konsentrasi klorida 1%, 2% dan 3.5%.

Mapping of ultrasonic thickness measurements using laser grid projection and image processing

2019 ◽  
Vol 61 (11) ◽  
pp. 643-649 ◽  
Author(s):  
T Tesfaye ◽  
M S Mohammed ◽  
K Ki-Seong
Keyword(s):  
Image Processing ◽  
Three Dimensional ◽  
Pattern Generator ◽  
Mapping Method ◽  
Oxide Semiconductor ◽  
Metal Loss ◽  
Thickness Gauge ◽  
Image Processing Algorithm ◽  
Thickness Measurements ◽  
Ultrasonic Thickness

A three-dimensional surface mapping method for ultrasonic thickness measurements is proposed to enable the dimensions and positions of measured values obtained by the conventional ultrasonic thickness gauges and flaw detectors on curved surfaces to be determined. The proposed system consists of a laser pattern generator and image processing methods. The laser grid produced by the pattern generator is projected onto the surface of the item to be inspected, mathematical relationships are developed to localise the grid nodes on the inspection surface and images are then captured using a complementary metal-oxide semiconductor (CMOS) camera. An image processing algorithm is developed to plot the scanned surface. The measurements performed using a thickness gauge are correlated with the plotted surface, which will enable thickness mapping. The experiments were carried out on a pipe with an artificial metal loss defect and the results showed that the developed method can accurately locate measured thickness values on a three-dimensional plotted surface.

My Pipes Are Corroding! When Should I Repair? Getting the Answers You Need for Maintaining Pipeline Integrity

2015 ◽  
Author(s):  
Michael Turnquist
Keyword(s):  
Finite Element ◽  
Life Assessment ◽  
Metal Loss ◽  
Element Analysis ◽  
Element Mesh ◽  
Level 3 ◽  
External Corrosion ◽  
Remaining Life Assessment ◽  
Ultrasonic Thickness

This case study exhibits how groundbreaking inspection methodologies combined with innovative computational analysis practices demonstrate the value of conducting fitness-for-service (FFS) assessments on sectional piping. In this instance, a fitness-for-service assessment was performed on two sections of piping experiencing external corrosion at the pipe-to-elbow seam welds. A full external scan and spot ultrasonic thickness (UT) readings were used to create the corroded geometry and verify accurate measurement of the remaining thicknesses in various corroded locations. This allowed for the actual corroded profiles to be accurately modeled using finite element analysis (FEA). Complications were present when modeling the observed metal loss. Through the use of innovative finite element mesh generation practices, the actual measured corroded geometry was modeled without the need for over-conservative geometric simplification. A Level 3 FFS assessment was then performed in addition to a remaining life assessment based on observed corrosion rates. The result of this analysis was that the piping could remain in service for at least two additional years before needing repair.

Ultrasonic thickness meter

1993 ◽  
Vol 26 (6) ◽  
pp. 323-324
Author(s):  
Gilardoni SpA
Keyword(s):  
Thickness Meter ◽  
Ultrasonic Thickness

Analysis of Variance and Covariance

2007 ◽  
Author(s):  
C. Patrick Doncaster ◽  
Andrew J. H. Davey
Keyword(s):  
Analysis Of Variance

Analysis of Variance Designs

2008 ◽  
Author(s):  
Glenn Gamst ◽  
Lawrence S. Meyers ◽  
A. J. Guarino
Keyword(s):  
Analysis Of Variance

Selflessness in Anorexia Nervosa as Reflected in the Rorschach Comprehensive System

2012 ◽  
Vol 33 (1) ◽  
pp. 78-93 ◽  
Author(s):  
Gili Curiel-Levy ◽  
Laura Canetti ◽  
Esti Galili-Weisstub ◽  
Myrna Milun ◽  
Eitan Gur ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Anorexia Nervosa ◽  
Analysis Of Variance ◽  
Clinical Observation ◽  
Comparison Group ◽  
Comprehensive System ◽  
Multivariate Analysis Of Variance ◽  
Rorschach Comprehensive System ◽  
Group A

This study examines the expression of selflessness – the tendency to ignore one’s own needs and serve others’ needs – in Rorschach protocols of women suffering from anorexia nervosa. The protocols of 35 women suffering from anorexia nervosa were compared to 30 protocols of a psychiatric comparison group. A multivariate analysis of variance over five variables (AG, PER, PHR, COP, and GHR) was significant: Anorexic patients showed higher characteristics of selflessness compared to the psychiatric comparison group. These findings contribute to the validation of the Rorschach technique and to the clinical observation of selflessness in anorexic patients, and they emphasize specific characteristics in the treatment of anorexia nervosa patients.

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