Message Board Thread - "Thermography on lagged steam piping "

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Thermography on lagged steam piping casparyd 11/15/2000
I work for the US Navy in San Diego.  There are about 15 military and civilians working here with 8 IR cameras.  We have been doing electrical equipment surveys
for quite awhile with great success.  I have recently been working on doing
steam piping.  Some Navy ships still run on steam, image that.  Anyway
most, if not all piping is lagged.  What I am looking for is wall thinning ,
leaks, bad welds and brazed joints.  We do not want to remove the lagging for a visual inspection.  As infrared is non-intrusive it would seem well suited for this type of work.  I have had some success on several shoots so far.  But, I was hoping that somewhere, someone may have covered some of this ground before.  I don't mind doing the research and all because there is a lot of it even after the basics are down. 

If any thermographers can shed additional light on this subject it would be greatly appreciated. 

Thank you in advance
Dan Caspary
RE:Thermography on lagged steam piping jdemonte 11/15/2000

My past life included a stint on the USS Minneapolis-Saint Paul out of Norfolk, VA. MM1/SS DeMonte to be exact. As my mechanical nuclear operator duties went, one of them, as you probably know, was to conduct extensive carbon steel corrosion inspections for all steam and sub safe components. The lagging used on some of the piping was always painted with a high emissivity paint such as bilge or Navy gray and light (pea soup) green. All three of these paints would make IR inspections of the piping a good choice. Any leakage from the steam to the lagging would show distinct thermal patterns on the surface of the lagging. One thing to consider, however, is that you will be looking at a cylindrical surface. You should always try to look perpendicular to each side of the pipe in order to reduce the effects of a diminishing viewing angle. If your viewing angle is parallel to the pipe lagging, the reflectance will be at it's greatest value. I remember how difficult it was to work on piping systems on a 688 class sub, so using a first surface mirror to reflect the hard to reach piping surface to your camera will serve you well. Visual inspections of discolored or damaged lagging may also lead you to areas of concern. Good luck with this endeavor, and feel free to contact me for any further questions that you may come up with.

Joseph DeMonte
Thermography Course Instructor
FLIR Systems, Inc.
(978) 901-8506
RE:Thermography on lagged steam piping Jose Miguel 4/4/2002
I work with lagged steam piping in power plants (20 inch diameter) and boiler external walls.
With IR you could detect internal isolation failures, heat losses from pipe supporting, steam loses from valves, etc.

You must be aware of sunny days, so in case of detecting a hot spot, you should check if sun beams are reflecting from the lagging to the camera (it gives much more elevated Tº what it is).

Emmisivity value increases dramatically from as-new lagging to oxydized or rusted surface. A contact thermocouple is a good tool to calibrate emissivity in accesible lines.
RE:RE:Thermography on lagged steam piping abayomi 7/9/2002
I am currently responsible for IR on all aspects of diesel and gas turbine power plants here in Bermuda. In particular, I am looking for
input from anyone with experience with IR on the exhaust pipes on large diesel engines. They have internal lagging around the exhaust and a thin metal outer covering on the lagging. I am picking up significant hot spots but there is resistance from maintenance staff as to the relevance of the thermal patterns. Any experience out there?
Re:Thermography on lagged steam piping paulpartin 12/20/2004
Joe, no comments to add to the piping dilemma, but I was on the Emory S. Land from '86-91, probably ran into you if you were on at that time. I worked in the NDT lab. Just went to level 1 training last week. Be good and have a good holiday season. Paul
Re:Thermography on lagged steam piping Manuel 12/21/2004
hi to all ..

"What I am looking for is wall thinning" ..

remember that exist portable ultrasonic thick detectors..

roberto cruz

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