Message Board Thread - "Thermography on Hydraulics and Engines "

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Thermography on Hydraulics and Engines Rich Pratt 7/14/2000
Can anyone recommend some good resources on scanning hydraulic components and diesel engines?

RE:Thermography on Hydraulics and Engines Gary Orlove 8/2/2000

Here is some information to get you started. - Gary


Temperature changes are often a precursor to many significant problems that occur in diesel and gasoline engines. For this reason, Infrared thermography is an integral part of most predictive/preventive maintenance programs. Infrared thermography can pick up small changes in temperature not visible to the human eye. It is a nondestructive, non-contact method of detecting impending problems within a predictive/preventive maintenance context. Following is a discussion of infrared thermography and a few of the predictive/preventative maintenance opportunities diesel and gasoline engines. See

Increasing Maintainability and Operability of Emergency Diesel Generators with Thermographic Inspections, - In the Nuclear Power Generation Industry, Emergency Diesel Generators are a critical component in ensuring the ability to safely operate the plant. Relegated to a standby role, this equipment must be immediately available to provide power to important plant equipment needed to safely shutdown the reactor, in the event of a loss of normal off-site sources of power. Consequently, maintenance, operation, and surveillance of these generators is performed under close scrutiny, and any deviations from established parameters can potentially lead to the mandatory shutdown of the reactor, and subsequent loss of power generation revenue. At Peach Bottom Atomic Power Station, Thermographic Inspection has become an integral part of the operation of the Diesel Generators. Generators are operated according to required surveillance tests, and a Thermographic Inspection is made at least twice a year. Some of the applications include checking for exhaust leaks, generator end bearing and cylinder exhaust temperatures, observing the effects of thermal mixing between crosstied cooling systems, and other mechanical and electrical troubleshooting. Proc. of SPIE Vol. 1933, Thermosense XV: An International Conference on Thermal Sensing and Imaging Diagnostic Applications, ed. L R Allen (Apr 1993) Copyright SPIE. See

Hydraulic Systems

Thermographic inspection of hydraulic systems -Hydraulic systems are the life blood of many industrial processes, especially the many forming presses used in the automotive industry. The loss of a press due to a hydraulic system failure can be very expensive, both in terms of reduced machine availability and diminished product quality. Thermography has proven to be an excellent maintenance inspection tool because the performance of hydraulic systems are easily characterized by their thermal signatures. Thermography also provides instantaneous, real time thermal data which is essential to understanding a dynamic system like hydraulics. This paper, based on many of Milan Plastics’ six years of experience with hydraulic systems, outlines the key components that can be inspected with thermography and discusses problems that are typically found. Proc. of SPIE Vol. 2766, Thermosense XVIII: An International Conference on Thermal Sensing and Imaging Diagnostic Application, ed. D D Burleigh, J WSpicer (Mar 1996) Copyright SPIE. See

Usefulness of high-resolution thermography in fault diagnosis of fluid power components and systems - Infrared thermography has been used routinely in industrial applications for quite a long time1*2*3.4. For example, the condition of electric power lines, district heating networks, electric circuits and components, heat exchangers, pipes and its insulations, cooling towers, and various machines and motors is monitored using infrared imaging techniques. Also the usage of this technology in predictive maintenance has proved successful, mainly because of effective computers and tailored softwares available4. However, the usage of thermal sensing technique in fluid power systems and components (or other automation systems in fact) is not as common. One apparent reason is that a fluid power circuit is not (and nor is a hydraulic component) an easy object of making thermal image analyses. Especially the high flow speed, fast pressure changes and fast movements makes the diagnosis complex and difficult. Also the number of people whose knowledge is good both in thermography and fluid power systems is not significant.
In this paper a preliminary study how thermography could be used in the condition monitoring, fault diagnosis and predictive maintenance of fluid power components and systems will be presented. The shortages and limitations of thermal unaging in the condition monitoring of fluid power are also discussed. Among many other cases the following will be discussed:
- pressure valves (leakage, wrong settings)
- check valves (leakage)
- cylinders (leakage and other damages)
- directionaJ valves and valve assemblies
- pumps and motors (leakage in piston or control plate, bearings).
The biggest advantage of using thermography in the predictive maintenance and fault diagnosis of fluid power components and systems could be achieved in the process industry and perhaps in the commissioning of fluid power systems in the industry. In the industry the predictive maintenance of fluid power with the aid of an infrared camera could be done as a part of condition monitoring of other systems for instance bearings. Proc. of SPIE Vol. 2766, Thermosense XVIII: An International Conference on Thermal Sensing and Imaging Diagnostic Application, ed. D D Burleigh, J WSpicer (Mar 1996) Copyright SPIE See
RE:RE:Thermography on Hydraulics and Engines Rich Pratt 8/28/2000
I ordered a couple of the papers you referenced from SPIE. The texts are excellent and very applicable to what we are doing. Unfortunately the multiple thermographic images the authors included are now blurry black and white copies of black and white copies. The woman at SPIE was very helpful and check to see if they had color copies of these images, but the black and white blobs were the best the had.


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