Newsletter: Lumut Branch May issue

Available Tools To Prevent CUI: Protective coatings

These coatings can protect carbon steel pipe from water, air, and corrosive chemicals. With those three elements, as well as time and a certain temperature range, corrosion will occur. The first line of defense is the protective jacketing. The second line of defense is insulation system maintenance. Protective coatings on the pipe provide a third line of defense in the prevention of CUI.

Immersion-grade coatings, which are organic, are becoming widely used to coat and protect pipes that operate at or below 300°F. The reason for this temperature limitation is that above that temperature, most organic coatings thermally decompose. Therefore, immersion-grade coatings are an effective tool up to a 300°F operating temperature. They can be considered a valuable tool on carbon steel pipes. The drawback to facility owners, of course, is that they are a financial investment—one that not every facility has been willing to make when operating on inadequate budgets.

In the article, “Corrosion Under Insulation: Prevention Measures” (Insulation Outlook, October 2007), Dr. Hira S. Ahluwalia describes thermal spray aluminum (TSA) coating in great detail. He points out that TSA coating is effective up to a maximum temperature of 1,000°F, much greater than the 300°F limitation of organic, immersion-grade coatings. This type of coating is reportedly more expensive than the immersion-grade coatings, and some facility owners may not think that CUI prevention is worth the investment. 

However, the expense needs to be evaluated financially through a life-cycle cost analysis, considering not just the initial cost of the TSA coating, but also the value of the pipe, its life expectancy, and the financial risks associated with repairing corroded pipes, fittings, and other components. If the facility is to be brought out of service for any extended period of time, offering an opportunity for water to intrude and CUI to occur, then TSA coatings should be considered. Therefore, TSA coatings are a valuable tool to prevent CUI for piping systems that operate at temperatures between 300°F and 1,000°F.

Source:http://www.insulation.org/articles/article.cfm?id=IO080302

5 signs You're going to make it Big One Day

We’ve all got dreams of making it ‘big’ one day, but how many of us actually follow through with those dreams? We make excuses for our lack of success, saying things like, “Life got in the way,” or “I can’t handle anymore rejection.”

But not you! You’re on the fast-track to fame and success. Or are you?

Think you’ve got what it takes to make it big? Here are some signs you’re right:

1. You’ve Got A Dream (A Big One!)

What’s your vision? What do you want to accomplish? What are your hopes and dreams? Having a dream – even if it’s a little vague – is crucial for success. Before you can start your journey, you need to have a goal in mind!

In the words of Walt Disney, "If you can dream it, you can do it." (And before you can do it, you've got to dream it!)

2. You’ve Got A Road Map, But You're Prepared To Take Detours

They say success is where preparation and opportunity meet. So, when opportunity comes ‘a knockin,’ you’re going to want to have your plan already in place. Think of it as your road map to making it big!

What steps do you need to take to get where you want to be? Who do you need to know? What skills do you need to have?

But, let's be real here, nothing EVER goes exactly according to plan. You need to be able to adapt to whatever life throws at you. Think of those things as detours. They're not a huge deal as long as you figure out how to get back on the main road!

3. You’re Extremely Curious

You need to have an innate fascination with whatever it is you’re working toward. You've got to learn as much as you can about the industry, the people, the culture, and so on. You need towant to be consumed by it. You've got to understand the problems and be excited about finding solutions. You’ve got to be passionate, excited, and curious about all areas of the biz.

When Larry King made his debut in radio, he made a point to become consumed in the biz. In addition to doing his own show, he did the weather reports, the sports updates, and the news broadcasts. He even volunteered to fill in in for people who were out sick, and took on double shifts.

Why? He wanted to learn all there was to know about the biz. He wanted to practice. He wanted to be good at what he did. The only way to do that was to explore and go above and beyond what was asked of him. He called it "taking extra batting practice."

4. You’re A Little Cocky (Just A Little)

If you really want to make it, you’ve got to have confidence in yourself and your abilities. Without confidence, you can so easily get crushed by negativity and criticism – things you will have to deal with once you hit the spotlight.

You have to be confident. You have to trust yourself. And you have to have a deep understanding that you’re going to make it. For actress Jennifer Lawrence, that understanding came at a young age.

“I always knew that I was going to be famous,” she told Vogue magazine. “I honest to God don't know how else to describe it. I used to lie in bed and wonder: ‘Am I going to be a local TV person? Am I going to be a motivational speaker?’ It wasn't a vision. But as it's kind of happening, you have this buried understanding: Of course.”

5. You Realize Failure Is A Minor Setback, Not A Game Changer

If you’re even thinking about making it big one day, the word “quit” can’t be in your vocabulary. In the end, you don’t succeed because you don’t fail; you succeed because you don’t give up. The second you quit, you’ve lost.

Take Michael Jordan, for example. He has a famous quote, "I've failed over and over again in my life, and that is why I succeed." The only reason he succeeded was because he didn't let those failures discourage him to the point of quitting. Why? Because he realized his failures were only minor setbacks - not game changers.

I guarantee you that everyone you look up to has failed at one point or another, but did that stop them from picking themselves back up and moving forward? 

If you’ve got all of these qualities – congratulations. I’m sure we’ll be hearing your name sometime soon!

source:https://www.linkedin.com/today/post/article/20140619132958-79588522-5-signs-you-re-going-to-make-it-big-one-day?trk=object-title

Tools To Prevent CUI: Insulation system maintenance

If the pipe insulation is covered with well-designed, well-installed, and well-sealed jacketing, as discussed in the above section, then it is well protected against CUI. However, once this has been accomplished, the system must be maintained. Therefore, the next tool in the CUI prevention toolbox is insulation system maintenance.

For example, consider an insulated pipe that:

• is several decades old
• has an original insulation system of the same age;
• is located in a relatively rainy climate (something other than the U.S. desert southwest and, at the extreme, along the coast of the Gulf of Mexico);
• has been shut down for an extended period of time during the system’s life;
• is uncoated; and
• has been poorly maintained.

In this case, it is highly likely that the pipe has suffered from CUI. It would be completely unrealistic for the owner or anyone else to expect to not find CUI. In such a case, the CUI is not necessarily the fault of the insulation system design. It further is probably not the fault of the protective jacketing or the insulation material(s). The problem is that when a system has not been well maintained, water—perhaps with dissolved salts from the Gulf of Mexico spray—eventually will get beneath the jacketing between the pipe and the insulation materials, and it will lead to corrosion of the pipe.

In his article, “Is There a Cure for Corrosion Under Insulation?” (Insulation Outlook, November 2005), Mike Lettich emphasizes the necessity for effective maintenance in the battle to prevent CUI. For example, if the insulated pipes have been walked on, resulting in denting of the metal jacketing, there will be water intrusion. If the caulk along the overlapped butt joints has not been periodically replaced, it will become brittle and lose its sealing capability, and rainwater eventually will leak into the system. If caulk around the penetrations—particularly along the top sides of the pipes—has not been examined and replaced as necessary, water will intrude.

For better or worse, the world experienced a prolonged period of very low energy prices from about 1985 to about 2002, with a few, occasional short-term spikes in natural gas prices. With low energy prices, many process pipelines simply were not well maintained due to inadequate maintenance budgets. (This was not the case with all facilities, but it occurred all too often.) With a poorly installed jacketing system—and one inadequately maintained—the insulation system will simply leak rainwater, and CUI will eventually occur. All types of insulation material can be used effectively, up to their design temperatures, if water is kept out of the system. If water gets into the insulation and CUI results, to then simply put all the blame on the materials that make up the insulation system is to put the blame where it should not be placed.

Source:http://www.insulation.org/articles/article.cfm?id=IO080302

Tools To Prevent CUI: Protective Jacketting

In terms of preventing CUI, it is worth examining what tools are available to prevent it. There are a number of different tools that can be used, some more effective than others and all with limitations.

The first rule to understanding prevention is to keep water out of the insulation. Regardless of the type of thermal insulation, keeping water out starts with the protective jacketing. 

The quality of the design, specification, procurement, installation, and maintenance of the protective jacketing system is always critical to preventing CUI. Standard 0.016-inch-thick aluminum jacketing, as well as steel sheet jacketing, installed with caulks and mastics, can effectively keep water out of the insulation system. To be effective, it is critical for everyone involved (the general contractor, insulation contractor, design engineer, and facility owner) to make certain that no shortcuts are taken in design, material specification, and installation. Both conventional aluminum jacketing and steel jacketing can be effective at keeping out the intrusion of water and preventing CUI. Hence, protective jacketing is the most important tool in the CUI prevention toolbox.

A new type of protective jacketing material that is seeing increasing interest is multilaminate, pressure-sensitive jacketing that can be purchased for either field installation or can be purchased factory applied to certain types of insulation. This family of materials essentially consists of industrial-grade tapes, available in 3 foot widths, that are weather resistant; impermeable to water or water vapor; resistant to many chemicals; and able to seal tightly with their pressure-sensitive, “peel-and-stick” surfaces. 

Some of these are available in industrial-grade weights with a thickness of almost 0.016

inches. An important accessory to making the system effective in keeping out water is a 2- to 4-inch-wide roll of tape to seal the joints and the penetrations. This type of material offers a jacketing that can be adhered to the insulation, thereby preventing moisture from accumulating between the jacket and the insulation. Its flexibility allows for easier installation and sealing at joints and penetrations as well as at termination points, making it very effective at keeping out water. Therefore, wide multi-laminate tapes should be included in the CUI prevention toolbox.

A third type of jacketing, that is durable and effective at keeping insulation beneath it dry, is a glass fiber lagging cloth with an acrylic weather coating mastic. This type of jacketing has the advantage of being able to seal penetrations effectively, to prevent water leakage. Another advantage is that is can be extremely durable, as well as being water proof. Therefore, lagging cloth with an acrylic weather coating mastic should be included as a tool in the CUI prevention toolbox.

Source: http://www.insulation.org/articles/article.cfm?id=IO080302

Alternative Inspection Methods to detect CUI

The present corrosion under insulation detection methods are:

Profile Radiography

Exposures are made of a small section of the pipe wall. A comparator block such as a Ricki T is used to calculate the remaining wall thickness of the pipe. The exposure source is usually Iridium 192, with Cobal 60 used for the pipes of heavier wall. (See Figure 1).

Profile radiography is an effective evaluation method, but becomes technically challenging in piping systems over 10 inches (25.4 cm) in diameter and only offers the limited luxury of verifying relatively small areas. This technique will not detect CISCC in stainless steels. In addition, readiation safety can be a real concern. Nobody can work within the area while the inspection is under way, this can result in downtime and manpower scheduling conflicts.

Ultrasonic Thickness Measurement

This is an effective method, but limited to a small area (Figure 2). It is expensive to cut the insulation holes and cover the holes with caps or covers. It is not practical to cut enough holes to get a reliable result. The inspection holes cut in the insulation may compromise the integrity of the insulation and add to the corrosion under insulation problem, if they are not recovered carefully. This technique will not detect CISCC in stainless steels.

Insulation Removal

The most effective method is to remove the insulation, check the surface condition of the pipe, and replace the insulation. This approach will detect CISCC in stainless steels; may require eddy current or liquid dye penetrant inspection. This is also the most expensive method in terms of cost and time lost. The logistics on insulation removal will probably involve asbestos and its attendant complications. Process related problems may occur, if the insulation is removed while the piping is in service.

Infrared

In the right conditions, infrared can be used to detect damp spots in the insulation, because there is usually a detectable temperature difference between the dry insulation and the wet insulation. Corrosion is a distinct possibility in the areas beneath the wet insulation.

Neutron Backscatter

This system is designed to detect wet insulation on pipes and vessels. A radioactive source emits high energy neutrons into the unsulation. If there is moisture in the insulation the hydrogen nuclei attenuate the energy of the neutrons. The instrument's gauge detector is only sensitive to low energy neutrons. The count displayed to the inspector is proportional to the amount of water in the insulation. Low counts per time period indicate low moisture presence.

Real-Time Radiography

Fluroscopy provides a clear view of the pipes outside diameter trhough the insulation, producing a silhouette of the pipe outside diameter (OD) on a TV-type monitor that is viewed during the inspection. No film is used or developed. The real-time device has a source and image intensifier/detector connected to a C-arm (see Figure 3). There are two major categories of RTR devices on the market today; one using a X-ray source and one using a radioactive source. Each has its own advantages and disadvantages, however the X-ray systems deliver far better resolution than the isotope type equipment.

The X-ray digital fluroscopy equipment operates at a maximum of 75 KV, a low level radiation source, but the voltage is adjustable to obtain the clearest image. this allows for safe operation without disruption in operating units or even confined spaces. The radiation does not penetrate the pipe wall as more powerful gamma-ray or x-ray would, instead it penetrates the insulation and images the profile of the pipe's outside wall. The radiation is generated electrically so the instrument is perfectly safe when the power is off, whereas the Iridium 192 used in wall shots produces gamma-radiation constantly, even when shielded within the camera. Therefore the gamma-ray camera always needs careful supervision and control during all operations, including transportation and shipping. The systems with the electrically generated X-rays are far more convenient for shipping.

The new systems come with a heads-up, video display. The helmet-mounted, visor-type video-display fress the system operator's hands so that he can maneuver the C-arm, while keeping the image before the operator at all times. The heads-up display also improves interpretation by shielding the screen from the sun. The video images can be printed on site using a video printer or recorded using a standard VCR for evaluation later.

Performing the Inspection

Using the sorting criteria listed above it is possible to prioritize a list of piping for inspection that is manageable in a reasonable time fram. The CUI inspection crew then inspects the pipes iso by iso.

The "C" shaped arm is the actual device used to scan the pipe. A cathode ray tube on one side generates the x-rays, shooting them across to the receiver on the other side. The operator manipulates the arm around the pipe, guiding it by the black and white heads up display on his hard-hat. A typical scan will go up the pipe while moving the arm about 45 degrees to both sides of the track. The C-arm is then rotated 180 degrees and the pipe is scanned downward in a similar fashion. After rotating 90 degrees the up and down process is repeated.

Results

To the untrained eye, the image in the screen would appear to indicate very serious corrosion. However, what is being imaged is the exfoliation of the rust (See Figures 4 and 5.) Performing the inspection in this manner the inspector can inspect a considerable amount of pipe in a short time.

Limitations

One of the main limitations of the system is the C arm. There are a couple of sizes of C-arms available. The manufacturer has had success in checking pipes up to 24 inches in diameter. These systems were not originally designed for the field but rather for laboratory work. This limitation has been addressed and the systems available today are more robust. However, they still require a lot of care and attention. There will always be some percentage of piping where real-time X-ray can not be used. The prime example is the center lines among tightly nested pipelines with little clearance between the pipes. Finally, while the X-rays are low energy, they are still radiation, and so the system must be used with extreme caution.

Source:https://inspectioneering.com/content/1996-11-01/116/inspection-techniques-for-dete

For more information about Corrosion and how to prevent it, contact us via our website at www.leopad.com

When Does Corrosion Under Insulation Occur?

The problem occurs on carbon steels and 300 series stainless steels. On the carbon steels it manifests as generalized or localized wall loss. With the stainless pipes it is often pitting and corrosion induced stress corrosion cracking (CISCC). Though failure can occur in a broad band of temperatures, corrosion becomes a significant concern in steel at temperatures between 32 F (0 C) and 300 F(149C). Corrosion under insulation is caused by the ingress of water into the insulation, which traps the water like a sponge in contact with the metal surface. The water can come from rain water, leakage, deluge system water, wash water, or swearing from temperature cycling or low temperature operation such as refrigeration units.

Systems Susceptible to CUI

API 570 specifies to the following areas as susceptible to CUI:

• Areas exposed to mist overspray from cooling water towers.
• Areas exposed to steam vents
• Areas exposed to deulge systems.
• Areas subject to process spills, ingress of moisture, or acid vapors.
• Carbon steel piping systems, including those insulated for personnel protection operating between 25 F and 250 F. CUI is particularly aggressive where operating temperatures cause frequent condensation and re-evaporation of atmospheric moisture.
• Carbon steel piping systems that normally operate in-service above 250 F (120 C) but are in intermittent service.
• Deadlegs and attachments that protrude from insulated piping and operate at a temperature different than the active line.
• Austenitic stainless steel piping systems that operate between 150 F and 400 F (60 C and 204C). These systems are susceptible to chloride stress corrosion cracking.
• Vibrating piping systems that have a tendency to inflict damage to insulation jacketing providing a path for water ingress.
• Steam traced piping systems that may experience tracing leaks, especially at the tubing fittings beneath the insulation
• Piping systems with deteriorated coatings and/or wrappings.
• Locations were insulation plugs have been removed to permit thickness measurements on insulated piping should receive particular attention

All equipment will be shut down at some time or other. The length of time and the frequency of the downtime spent at ambient temperature may well contribute to the amount of corrosion under insulation that occurs in the equipment. It would be a daunting task to muster the resoures needed to tackle this extensive list of piping with the traditional inspection methods. This is where real-time X-ray offers a real advantage. Once the damaged areas are indentified, follow-up X-rays and ultrasonics can measure the loss by external corrosion. These techniques will not detect CISCC in stainless steels.

Alternative inspection methods will be discussed in our next blog...

Source:https://inspectioneering.com/content/1996-11-01/116/inspection-techniques-for-dete

For more information about Corrosion and how to prevent it, contact us via our website at www.leopad.com