Ralf Grispen

Commercial Manager and

Level II inspector

Thermografisch &

Adviesbureau Uden BV

r.grispen@thermografie.nl

One of the companies that realized the importance of pipework inspections with thermal imaging cameras is Royal Vopak, the world’s largest provider of storage facilities for bulk liquids. At the Vopak storage facility in Vlaardingen, the Netherlands, steam is transported at 170 °C through a network of pipes with a total length of over 1 kilometer. To determine the exact amount of energy loss during that transportation process Vopak hired the Dutch thermographic consultancy agency Thermografisch Adviesbureau Uden BV to carry out a thorough survey of the pipework insulation.

Vopak provides storage and transportation facilities all over the world and for just about every possible type of chemical. Whether it’s liquid or gaseous chemicals, oil products, petrochemicals, biofuels, vegetable oils or Liquefied Natural Gas (LNG), Vopak offers complete storage and transshipment solutions at 80 terminals in 30 countries, covering and connecting the world’s major shipping lanes. Vopak offers more storage capacity than any other independent tank terminal operator in the world.

According to the management trainee responsible for energy projects at the Vopak terminal in Vlaardingen, Tim Hoogstrate, there are several reasons why his interest in thermal imaging surveys peaked. “We use steam to prevent the vegetable oil we handle at this terminal from solidifying. To transport the steam to the vegetable oil tanks we have a network of steam pipes that is over 1 kilometer in length that spans the entire terminal. Since all pipework insulation is subject to degeneration over time we need to know where the pipework insulation has to be renewed.”

Minimizing Energy Loss Is Hot

This information is not only important for financial reasons, explains Hoogstrate. “Obviously minimizing energy loss is a hot topic nowadays, for both environmental and financial reasons, but security is also a factor here. If the insulation is faulty the external surface of the pipes can become dangerously hot. And since the pipeline stretches throughout the terminal accidents can happen all too easily.”

Using thermal imaging cameras for pipework insulation inspection is nothing new, but in this case the client needed something more: a calculation of the exact amount of energy loss that is caused by each individual insulation failure. That made this assignment a very interesting challenge.

Not an Easy Task

Acquiring accurate thermographic readings was not an easy task. Any thermographer will tell you thermographic inspections of metal surfaces such as these pipes can be quite challenging. Due to the high reflectivity of metal surfaces you have to painstakingly choose your angle in order to avoid infrared reflections that ruin the thermographic readings and each piece of pipework has a different emissivity value due to varying levels of oxidation. To solve these problems we had to pull out all the stops. We used every thermography trick in the book. Not only did we choose all angles carefully and correct the readings for the reflected apparent temperature, we also used thermographic calibration paint and calibration tape to ensure that every reading was accurate. One factor that made our job easier was the thermal imaging camera we used. The FLIR P660 is highly accurate and provides crisp thermal images at a resolution of 640 x 480 pixels and it is also easy to use, with several outstanding special features such as voice comments and automatically embedded GPS coordinates.

Accuracy of Readings Is Vital

The accuracy of the readings was a vital requirement for Cyril Vallen from the energy loss consultancy agency Xellins. “I cannot stress enough how important it is that the thermal data is accurate. I have highly advanced mathematic models at my disposal that can be used to accurately determine the exact amount of energy that is lost at each problem area, but if the thermal data I feed into my models are incorrect then the outcome of the calculation is completely useless. Even extremely small deviations below 1 °C can seriously influence the outcome.”

Together with us Vallen spent several nights at the terminal, looking for problem areas. “We found about 150 locations that warranted further investigation. The analysis is not completely finished yet, but I can reveal that in several locations the insulation defects can be called severe. To put it in some kind of perspective: in some locations the financial effect of the energy loss is similar to tossing one or more high quality flat-screen televisions in the trash each year.” With the information from Vallen’s calculations Hoogstrate can accurately determine the cost of each problem area and, combined with a repairs quotation from an insulation specialist, he can then immediately see whether repairing the insulation in that particular location is worth his while.