Page 212 - CW E-Magazine (26-9-2023)

Special Report
(He Std). Sniff test can fi nd very small
leaks, identifi es the exact location and
can be used to determine the leak fl ow
rate. Radioisotope method is extremely
accurate, butrequires special train-
ing for operators. It requires selection
of right type of radioisotopes and use
of radiation (specially λ-Ray) detec- 2. Neale Michael, A Guide to Con-
tion device and is relatively expen-
sive. Dye penetrant test is very simple
and inexpensive, but is not accurate
Fig. 20 :Thermogram of a HP steam pipe showing Leakage & Insulation damage in a super for very small leakages. Ultrasonic
thermal power plant leak testing is performed based on the
principle that sound waves (ultrasonic
frequency range) transmit through the
leakage point of the pressure vessel. It
uses an ultrasonic gadget/equipment
to locate leakage point and size, but
is usually unable to measure the leak-
age fl ow rate. Acoustic emission test-
ing and IR thermography scanning are
highly advanced and very expensive
techniques. Both the techniques are
on-line in nature and require skilled
Insulation damage
Heat leakage in a steam installation due and trained operators. They are very
to insuffi cient insulation. precise and give very high lead-time
between detection of likely leak and
the actual leak taking place in a pres-
sure vessel. AE testing is based on
the principle that very high frequen-
cy acoustic waves are generated and
radiated from metals undergoing defor-
mation and fracture process, which
is measured by special transducers
mounted on different locations of the
vulnerable areas of the pressure ves-
Fig. 21: Thermograms showing steam leakage from different pressure vessels sels such as welded joints and bends,
etc. IR thermography is based on
417.4 detection of IR energy radiated by an
378.9 object using a semiconductor detector,
340.3 a set of lenses and grater, and electronic
301.8 circuit producing a thermal image
263.3 of the object. IR scanning is a non-
224.8 intrusive and non-contact mapping of
186.2 thermal images of the surface and is
147.7 very rapid facilitating easy interpreta-
109.2 tion. Both techniques discover the root
70.6 cause of the leakage/defect in the pres-
32.1 sure vessels and are preferred methods
o F for very critical pressure vessels from
Fig. 22: Leakage of process gas due to lining defect in an oil refi nery catalytic converter the view point of downtime losses and
212 Chemical Weekly September 26, 2023
Contents Index to Advertisers Index to Products Advertised
Special Report
safety risk/hazards involved in the analysis in water distribution net- 12. Nondestructive Testing Handbook,
plant. works. Control Engineering Prac- Volume 6 “Acoustic Emission Test-
ing”, Third Edition, American Society
Target Your Market More Effectively
tice, 19 (10), 1157-1167.
REFERENCES 7. Hydrostatic Pressure Testing, of Nondestructive Testing (ASNT).
1. Collacot R.A, Mechanical Fault Pressure Vessel Design and Engi- 13. Ahmad, S., Ahmad,Z., Kim, C.H.,
IndiaChemTrade
ChemImpex
Diagnosis, (1977) Chapman and neering, American Society of Kim, J.M., “A method for pipeline
Hall, Ltd., London. Mechanical Engineers (ASME), leak detection based on Acoustic
For subscribers only
Emission & deep learning, Multi-
Section – VIII. Free for subscribers of Chemical Weekly
ChemImpex, the trade database, tracks, on a daily IndiaChemTrade provides consolidated trade statistics
dition Monitoring of Machinery, 8. Acoustic Emission Examination of
disciplinary Digital Publication
Fiber-Reinforced Plastic Vessels,
Department of Industry (1979),
Institute (MDPI), (Feb. 2022), Basel,
basis, exports and imports of chemicals and related of India. The information provided here is based on the
Her Majesty’s Stationery Offi ce, Article 11, Subsection A, Sec- Switzerland.
tion V, Boiler and Pressure Vessel 14. Prabhu, V., Vairaval, K.S., Velnath,
London.
products through the major ports in India — a vital annual trade data published by the Directorate General
of Commercial Intelligence and Statistics, Government
source of commercial intelligence. Find out on-line
3. N. Hilleret, “Leak detection”, Edit- Code, American Society of Mecha- R., “Leak Detection in high pres-
how international markets are moving; where your of India. The database can be searched by: Chemical
ed by S. Turner, Proc. CAS Vacuum
sure vessels using non-intrusive
nical Engineers.
I.O.P.
Conference
methods”,
Technology, Snekersten, 1999, 9. Acoustic Emission Examination of
competitors are exporting and at what price; where Name/Harmonised Code to obtain the consolidated
CERN 99/05 (CERN, Geneva, Metallic Vessels During Pressure Series: Material Science and Engi-
imports are coming from and how their prices are trade (import or export) in that item; or by Country to
Testing, Article 12, Subsection
1999), p. 203.
neering, (2021), 1069012015.
moving. Download all this data,
4. Murvay, P.S. and Silea, I., 2012. A seamlessly, for a obtain the trade (import or export) in all chemicals and
A, Section V, Boiler and Pressure 15. Kaplan Herbert., ASNT Level-III
Vessel Code, American Society of
survey on gas leak detection and
small fee — online, anytime, with no hassles. related products between India and that country
Study Guide on Infrared and Ther-
localization techniques. Journal Mechanical Engineers. mal Testing Method (2001), The
ChemXchange
of LossPrevention in the Process 10. Standard Practice for Leak De- American Society of Non-destruc-
Industries, 25 (6), 966-973. tection and Location Using Sur- tive Testing, Inc.
Open to all registered users — no subscription required
5. Colombo, A.F., Lee, P. and Karney, face-Mounted Acoustic Emission 16. Chakravorty S.K., Thermography
of Power Systems-Case Studies,
ChemXchange — the chemical exchange with a difference — is where you can identify your buyers and sup-
B.W., 2009. A selective literature
Sensors, American Society of
plyers on-line, any time. This unique platform is free to all advertisers in the print version of Chemical Weekly.
(2007), Seminar Proceedings on
Mechanical Engineers: Standard –
review of transient-based leak
detection methods. Journal of E1211-97. Machinery Health Management,
For more information contact: 022-24044477. Fax: 022-24044450
Hydro-environment Research, 2(4), 11. Non-Destructive Testing – Acous- Federation of Indian Chambers of
Commerce & Industry, New Delhi.
212-227. Email: corporate@chemicalweekly.com or log on to chemicalweekly.com
tic Emission – Examination of
6. Pérez, R., Puig, V., Pascual, J., Que- Metallic Pressure Equipment during 17. Thermal Imaging Guidebook for
vedo, J., Landeros, E. and Peralta, Proof Testing; Planar Location of Industrial Applications, (2011),
A., 2011. Methodology for leakage AE Sources, European Committee Infrared Training Centre, FLIR
isolation using pressure sensitivity of Standardization, DIN EN 14584. Systems AB, USA.
Mrs. Usha S. - usha@hpicindia.com
Chemical Weekly September 26, 2023 213