Maintenance of Below-Ambient Applications

There are a variety of different types of ducts, pipes, and equipment that operate below ambient temperature. The primary purpose of the insulation in these cases is to prevent surface condensation and reduce energy use. The cost penalties of surface condensation vary from application to application, but having condensation within the insulation can be severe. 

For example, in typical indoor commercial heating, ventilating, and air-conditioning (HVAC) applications, condensation can get into electrical equipment, run onto floors creating a safety hazard, or damage building materials. Wet insulation, in turn, performs poorly, possibly leading to condensation on the surface of the jacketing and energy waste. It can also increase the load on mechanical cooling equipment, possibly resulting in a compressor getting overloaded and burning out. In industrial applications, condensation may corrode the carbon steel onto which it drips, increasing maintenance costs. Overall, water condensation will create all sorts of costly operational headaches that the facility owner should make an effort to avoid.

Porous insulations, such as mineral fiber insulation, can be used on below ambient applications as long as they are covered with a low-vapor-permeance jacketing, referred to as a vapor retarder. It is prudent to use these systems on air-handling ductwork down to a moderate temperature of about 50°F. A drawback to this type of insulation system is that, over time, holes or other imperfections may develop in the jacketing and could allow water vapor intrusion that then condenses on the cold surface, resulting in wet insulation. Since such holes can easily be patched with self-adhering tape, periodic inspections should be conducted to identify and repair these spots before condensation problems develop.

For chilled temperatures below 50°F, such as chilled water pipes, and/or for a relative humidity (RH) above 90 percent, a more robust system—either from an overall low water vapor permeance perspective or a wicking capability—is required. A lower permeance jacketing should ideally be a zero-vapor-permeance material (called a vapor barrier) that is extremely well sealed to itself to prevent any water intrusion. These zero-permeance jacketing materials include both sheet plastic and a self-adhering laminate. For wicking capability, the wicking type of fibrous pipe insulation can provide performance free of vapor condensation problems on chilled water lines down to about 40°F in less than extreme humidity conditions. Both types of systems, however, must be well maintained to avoid water condensation problems.

When well maintained, closed cell foams, which have low vapor permeability values, are well suited for below-ambient systems with minimum maintenance problems. The thicker the insulation, the lower the vapor permeance (vapor permeance equals vapor permeability and thickness). In general, these closed cell foams perform well with chilled water systems and high relative humidity. However, all seams and butt joints must be well sealed. Breaks in the seals and gaps in the closed cell foam insulation material will allow water vapor to intrude; this water vapor, in turn, will condense. This condensation may take more time to develop than with a porous, fibrous insulation material, but with a constant high vapor pressure, it will eventually result in water accumulation in the insulation. This will compromise its thermal performance and lead to the types of condensation problems already mentioned.

For outdoor applications where weather protection is required and/or for very high vapor pressure differential indoor conditions, these closed cell insulation materials perform best when combined with a zero-permeance vapor barrier (as opposed to a vapor retarder). In an actual application, if such a vapor barrier jacket is used, it must be sealed completely to prevent water intrusion or water vapor condensation within the insulation. Certain sheet plastic materials and the new self-adhering, laminate jacketing materials—mentioned earlier for high-temperature systems—can simultaneously provide both weather and vapor barrier protection for below-ambient systems.

For extremely high humidity conditions combined with low operating temperature systems, located either indoors or outdoors, a zero-vapor-permeance system with redundancy will perform best. This can be achieved with at least 2 inches of inorganic cellular insulation covered with the appropriate vapor barrier jacketing. The jacketing should have zero vapor permeance, and the 2 inches of inorganic cellular insulation will have near zero vapor permeance. Further, this type of cellular insulation will not absorb water, should it somehow condense against the insulation. Such an insulation system, however, still requires maintenance to prevent moisture condensation over time. The jacketing must be periodically inspected for holes, and the inorganic cellular insulation must be periodically inspected for any physical damage that might reduce its thickness, leading to surface condensation.

Regardless of the insulation type or low-vapor-permeance jacketing, the insulation system for below-ambient applications should be well designed and well maintained. In most cases, if the insulation system is ignored and/or abused, eventually water condensation problems can occur. The penalty to the owner can be water damage to stored materials, building materials, and equipment, as well as mold growth, energy waste, and cooling system overloads.

The Bottom Line

Well-maintained thermal insulation reduces heat loss and saves money. Damaged insulation saves less money, and missing insulation saves no money at all. With crude oil at about $65 per barrel, delivered heating oil at $2.50 per gallon, and delivered natural gas at more than $10 per million Btus, every day spent ignoring damaged or missing insulation is another day of paying the high cost of wasted energy.

Two years ago, crude oil was trading at about $50 per barrel. Since then, crude oil has sold for as much as $77 per barrel, and now gasoline is selling for a record average price of $3.20 per gallon. People keep waiting for energy prices to drop, but even when prices drop for a few months, they jump up again to an even higher level than they were previously. This is no time to waste energy. Thermal insulation maintenance is easy and inexpensive when compared to energy prices. Those in the insulation industry need to help the managers of industrial facilities understand the economics of insulation.

Whether the motivation is to reduce energy use, to prevent CUI, or to maintain boiler temperatures, when it comes to thermal insulation and its maintenance the old saying, “Pay now or pay later,” is appropriate. The cost of not maintaining insulation correctly is too great for facility owners to ignore.

Source:http://www.insulation.org/articles/article.cfm?id=IO070701

Case Study: Chevron Richmond refinery fire resulted from corrosion of aging pipe

RICHMOND -- A metallurgical laboratory report released Wednesday confirms earlier conclusions that corrosion led to the rupture of a 36-year-old pipe and a subsequent fire at Chevron's refinery on Aug 6, 2012, prompting renewed criticism from investigators about the company's failure to replace the worn piece of equipment.

The 109-page report, prepared by Anamet in Hayward, concludes that the 8-inch carbon steel pipe had low silicon content and was vulnerable to corrosion from crude oil heavy in sulfur.

"Based on the results of this evaluation," the report states, "sulfidation corrosion caused wall thinning that led to rupture."

In a prepared statement, Ellen Widess, chief of the state Division of Occupational Safety and Health, also known as Cal/OSHA, said the latest report "confirms what Chevron already knew -- that the pipe was severely corroded and should have been replaced -- but failed to act on before the August fire."

Investigators also noted that Chevron workers responding to the leak may have exacerbated the problem by trying to fix it while the unit remained in operation. The corroded pipe may have been punctured when Chevron firefighters used sharp tools to strip away insulation in search of the leak, accelerating the release of gas oil.

The report comes as part of an ongoing investigation by the U.S. Chemical Safety Board, Cal/OSHA, the United Steelworkers union and Chevron. Chemical Safety Board Chairman Rafael Moure-Eraso said in a statement Wednesday, "We hope this report receives widespread attention throughout the petrochemical industry as a precaution to all refiners to carefully examine potential corrosion mechanisms and use the safest possible materials of construction to avoid failures."

In January, Cal/OSHA slapped the oil giant with $1 million in fines -- the biggest penalty in the agency's history -- for failing to replace the corroded pipe, not implementing its own emergency procedures and violations in leak-repair procedures.

Chevron spokesman Sean Comey on Wednesday said the report's findings are consistent with Chevron's internal probe. "Chevron U.S.A. is inspecting every pipe component in the crude unit susceptible to sulfidation corrosion," Comey wrote in an email. "Any component found to be unsuitable for service will be replaced before restarting the unit."

But Chemical Safety Board officials have said the corroded pipe should have been replaced years earlier and that Chevron mismanaged the problem on Aug. 6. The smoky fire was sparked after the ruptured pipe leaked high-temperature gas oil and hydrocarbons, which soon ignited and resulted in six minor injuries on the site and sent more than 15,000 area residents to hospitals.

"Chevron should have shut down the crude unit as soon as a leak was observed and removed workers to a safe location," Moure-Eraso said. "Continuing to trouble-shoot the problem and having firefighters remove insulation searching for a leak -- while flammable hydrocarbons were flowing through the leaking piping -- was inconsistent with good safety practice."

The board's investigation is ongoing, and a report detailing its findings is expected this year. Assemblywoman Nancy Skinner, D-Berkeley, issued a statement Wednesday saying the report "demonstrates once again that Chevron has failed to properly monitor facilities and that the Richmond refinery fire could have been prevented."

Skinner didn't specify a particular course of action but wrote, "Monetary penalties alone may not suffice."

Chevron critics say the refinery was negligent and cut corners on maintenance. "This latest report validates what we've all known, that sulfidation and poor monitoring played a key role in the fire," said Andres Soto of Communities for a Better Environment, a local watchdog group. "Not only did Chevron violate their own standards in not replacing a 40-year-old pipe, we are concerned that aging and vulnerable pipes are still in place throughout their system."

Chevron spokesman Comey said the refinery is committed to the highest safety standards.

"We want to be clear that our strong focus is on preventing a similar incident from happening in the future," Comey said. "We are implementing corrective actions that will strengthen management oversight, process safety, mechanical integrity and leak response."

For best solution to detect Corrosion under insulation, contact us at hq@leopad.com

Source:http://www.tombutt.com/forum/2013/130214.htm

Insulation Installation Checklist

There is an old saying: Measure twice, cut once. We all have "check" or "to do" lists to help us remember what needs to be done. Many of us rely on our memory, but it is usually a good idea to put the lists in writing so that when we are in a hurry we do not forget anything. The checklists below were developed primarily for below-ambient piping systems but would apply to any insulation application. The items listed are in general terms, so there may be additional items to add to tailor the list to your needs based on past experience.

There are three main functions that take place during an insulation installation: 

(1) job layout or estimation

(2) actual installation

(3) quality inspection of the job once it is complete. 

The checklists below have been broken out for these three functions. The responsible party for each function also is noted.

Job Layout/Estimation
(Responsible Party: Estimator)

1. Review all system operating temperatures to be sure they are consistent with insulation use temperatures. Consider any temperature cycling and/or yearly maintenance that may affect system temperatures.
   
2. Determine the desired design conditions and the performance requirements of the insulation system. For outdoor systems, be sure to take into account the site location, likely weather conditions, and weather extremes when formulating the proper design conditions. Based on this information, determine the appropriate insulation thickness to be used.
   
3. Based on the site conditions and expected service conditions (UV exposure, exposure to chemicals, mechanical abuse, etc.), select the proper jacketing/protective covering/coating for the insulation. Note that many sites will have "standard practices" or internal specifications that will call out insulation system finish requirements.
   
4. Consider the following when deciding on the insulation configuration/style.
• Method of installation - i.e., mechanical attachment, adhesive, clam-shell, slide-on or slit, etc.
  
• Trade-off between labor and cost of materials. Some insulation systems cost more out of the box but install faster than cheaper systems. This saves labor and time during installation.
  
• Trade-off between labor and insulation system performance: Factory-fabricated fittings may cost more in materials but save labor and improve uniformity and performance.
  
• Trade-off between up-front material cost and maintenance costs down the road: Jacketed systems may cost more than those with a mastic finish but usually require less maintenance during the life of the insulation system.
  
• Configuration and type of equipment to be insulated. What is the geometry? Take into account the fittings, valves, pumps, etc. How will these be insulated?
5. Review the layout of the system or item to be insulated to be sure there is sufficient room for the insulation thickness specified without compressing the insulation or having the insulation come in direct contact with the insulation on other pipes or pieces of equipment. If not, can this be corrected? Check and see if there are protrusions along the system. Are they long enough to accommodate the recommended amount of insulation? If not, can they be extended or removed?
   
6. Lay out the job in a manner to eliminate seams or minimize insulation joints as much as possible. If multiple layers of insulation are required due to thickness or other performance requirements, the insulation joints of successive layers should be offset from the insulation joints of the previous layer.
   
7. When deciding on how to achieve the desired insulation thickness, consider practical handling of the insulation during installation (including the bending radius of the material) as well as the ability to achieve full joint closure. In addition, consult the insulation distributor or fabricator to verify the availability of different insulation sizes and configurations in order to select the most cost-effective way to achieve the desired thickness.
   
8. Consider the required time frame for completing the job. If the time frame is short, as is typical for maintenance during a plant shutdown, you may want to consider using insulation materials that are quicker and easier to install (e.g., self-seal or factory-fabricated products) because of the time saved, even though the initial cost of these materials may be higher.
   
9. Consider the availability of materials to be sure they can be delivered to the job in time.
   
10. Consider the availability of labor and the skill of the labor pool, as this may make a difference in the choice of materials.
    
11. Consider how important aesthetics are for the job.

Installation                                                       
(Responsible Party: Foreman)

1. Review work orders/specifications for areas to be insulated and materials (thicknesses) required. Lay out a plan/schedule for areas to insulate first, coordinating with other trades that may be working in the area. Include your safety training and any special safety equipment that may be needed for the job.
   
2. Be sure all materials (insulation, accessories?adhesives, tapes, jacketing, fittings, etc.?and tools) are on site or are scheduled to be delivered at the appropriate time. Be sure all materials are stored in a clean, dry room.
   
3. Check materials against what was specified (i.e., proper sizes and thicknesses). Organize insulation according to size and thickness.
   
4. Know job site conditions, including where other trades are working, what the weather will be over the period of the job, etc. Understand access to the working area. Because of potentially damaging environmental conditions, insulation used on outdoor applications nearly always requires protection (coating, jacketing, or cladding) from mechanical abuse and UV resistance. Remember, it is also important to protect the system from moisture intrusion during the installation process. Good practice dictates that no more insulation be applied in a day than can be properly sealed and protected from weather before leaving the site at the end of the shift.
   
5. Check equipment/tools (lifts, etc.) to be sure everything is in place for what needs to be done.
   
6. Check manpower and review the experience of workers. Develop a manpower allocation plan accordingly.
   
7. Review the insulation manufacturer's recommended installation procedures. If there are any questions, contact the manufacturer for recommendations.
   
8. Check to be sure the piping system or equipment is turned off and at ambient conditions. Make sure it is clean and free of dirt or moisture.
   
9. For most applications, it is recommended to apply the fittings first (which may be available for purchase pre-fabricated by a fabricator or the manufacturer, or can be pre-fabricated at an off-site location). After the fittings are installed, application can begin on the straight runs. The straight length material is usually easier to install than fitting insulation, so the straight run work will progress more quickly. Protrusions to the insulation system must be properly insulated and sealed. For below-ambient systems, protrusions should be insulated a distance of four times the insulation system thickness when possible. Protrusion on above-ambient systems should be insulated a distance of two times the insulation system thickness. For complex applications, contact the manufacturer for recommendations.
   
10. Inspect workmanship as the materials are being installed. Notify appropriate personnel if problems arise.
    
11. At the end of each day, be sure all materials are put away in a clean, dry area and that the installed portion of the job has been appropriately sealed/closed in such a way to prevent any damage from other trades or from the weather. Make sure all scrap insulation material resulting from field fabrication is either (1) put back in appropriate boxes to maintain size identification, or (2) appropriately disposed of.
    
12. On cold applications, make sure that all seams are glued and sealed. Install vapor stops when needed (for details, contact the insulation manufacturer).
    
13. When the job is finished, make a final inspection.

Quality Inspection
(Responsible Party: Engineer or Job Inspector)

1. Obtain a list of all areas that were specified to be insulated (including material type and thickness). Obtain a data sheet and appropriate installation instructions from the manufacturer for each material.
   
2. Conduct a preliminary inspection of the entire job. Make a list of any obvious issues that may need to be replaced, repaired, or corrected. Be sure all areas that were called out for insulation have been insulated. Also check for the overall neatness of the job.
   
3. Check that installed materials comply with those specified (material type and size). Material type and size (ID and thickness) generally can be found on the product box or on the insulation itself.
   
4. Ensure that all seams (longitudinal, butt joints, and terminations) have been sealed properly per manufacturer recommendations. Check all fittings, valves, etc. to be sure the insulation is sealed properly at any termination points.
   
5. When checking materials and insulation systems, be sure there are no tears, cuts, or damage that would cause performance issues. If any are found, the damage must be repaired or the section of insulation completely replaced. Also, make sure that none of the insulation is wet and there is no moisture between the insulation and the substrate.
   
6. On straight runs, make sure that seams are facing down to reduce weight/pressure on the seam.
   
7. Inspect the insulation finish (jacketing, coating, or mastic) for damage and defects. For outdoor applications, it is generally recommended that all insulation materials be protected from the elements and mechanical abuse by jacketing or coatings, and that all jacketing laps should be positioned to shed water.
   
8. On pipe and supported equipment, review all hanger and support areas to be sure they were handled according to manufacturer recommendations. The insulation should not be compressed, as the thickness of the insulation should not be compromised. Also, check all protrusions to ensure that they are properly insulated and sealed.
   
9. If the system has been turned on, look for any signs of condensation or ice formation.

By using these checklists, and adjusting them for personal use by adding or modifying steps based on your experience, the job should meet the end user's expectations and come in either at or below budget. "Measure twice, cut once" pays off more times than not in the long run. Taking short-cuts, particularly on an application involving below-ambient operating temperatures, is a bad bet.

For more information about insulation, contact us at hq@leopad.com

Source:http://www.insulation.org/io/article.cfm?id=IO130201

LUMUT BRANCH NEWSLETTER - JUNE 2014

Leaders: Beware of Followers

As a leader, have you ever had team members who showed little enthusiasm for your ideas? Subordinates who complied with your decisions more out of duty than eagerness?

Why do Leaders need true followers?
Followers are an essential part of the leadership equation. Without good followers, becoming a good leader is difficult as the proverb says: “He who thinks he leads, but has no followers, is only taking a walk”. Everyone aspires to be a leader but what is the chief ingredient that makes a leader effective; the followers. A good leader will not underestimate the power of followers. A good leader knows the importance of followers and is aware of the type of followers he has.

Followers impact leaders and the leadership process. Followers provide the “horsepower” to organizational performance as they are the primary contributors to the success of any organizational outcomes. Therefore, improving followership influence will have a beneficial impact on business performance.

Focusing on leadership alone is like trying to understand clapping by studying only the left hand.” Jonathan Haidt

People display followership when they express, through their words or actions, respect and support for a person they view as their leader, and openness to be influenced by him or her in that capacity. One could argue that any good leader is in turn a good follower. All leaders have their own leaders. Followership can take on a shifting role perspective, in some situations, an individual may be a leader and in others a follower depending on the context of the organizational goals.

The Leadership Theories:

The Leader-Member Exchange (LMX) theory of leadership focuses on the interactions between leaders and followers and understands that it is these interactions that are the centre of the leadership process. Under this theory leaders differentiate their followers based on their perception of their followers’ competence/skills, trustworthiness, and motivation to assume greater responsibilities Leaders then treat those with “high-LMX” differently and prefer them to those who have “low-LMX”.

Contingency or Situational models state the effectiveness of a leader's behaviour will be contingent upon the organizational situation. Different situations call for different styles of leadership, and the effectiveness of a leader's approach depends upon the needs of the specific situation. Leadership styles and situational control can be matched either by changing the leader’s personality or by changing the individual’s situational control in order to affect organization or group performance.

The days of leaders saying “Jump!” and subordinates asking “How high?” are over. Either people are on board with your leadership or not. Not so simple.

The influencing process is made complex because followers are not a monolithic group. Leaders wanting to build high performing teams need to be aware of the important role followership plays in group dynamics and team performance.

Source:https://www.linkedin.com/pulse/article/20141116040445-150905450-leaders-beware-of-followers?trk=prof-post

Tools To Prevent CUI: Insulation materials

Many different types of insulation materials are used on above-ambient pipes and equipment in industrial facilities. It is important to understand that if the facility owner keeps water from intruding into the insulation system in the first place, the facility is not likely to suffer from CUI. 

If water does occasionally intrude, coatings on the carbon steel pipes and equipment are a backup defense in the CUI prevention battle, as they protect the pipe itself. If this has been done, then any type of thermal insulation, well maintained and operating within its normal temperature limits, can be used without CUI occurring. Nevertheless, under certain circumstances, water, with dissolved corrosive chemicals, sometimes does intrude. It sits on an uncoated carbon steel pipe for extended periods of time. In those cases, certain types of insulation have features that make them tools in the CUI prevention toolbox.

The first of these is hydrophobic (or waterproof) insulation. Several types of commercially available insulation materials have a chemical hydrophobe added in sufficient quantity to make them truly water repellent. These include perlite block and pipe, aerogel blankets, and certain designated hydrophobic microporous insulations (those specifically coated with a hydrophobe). Mineral fiber insulation materials use the same type of hydrophobe, but in lesser percentages than the other materials, and they can still absorb water. Hence, while mineral fiber insulation is somewhat water repellent, it is a wicking material and cannot really be considered water repellent in the way that the other three materials can.

The hydrophobe typically used for some of these hydrophobic insulations is an organic silicone emulsion. It can be added during material manufacturing process. In the case of aerogel insulation, the material is made hydrophobic by virtue of the manufacturing process, by which organic methyl groups are added to the inorganic silica aerogel material. In all cases, this hydrophobic treatment will remain functional apparently up to a temperature range of 400° to 600°F. In that temperature range, the organics, that make the insulation hydrophobic, start to decompose and the insulation becomes less hydrophobic. Therefore, service temperature is the major limitation of the hydrophobe within hydrophobic insulation, regardless of insulation type.

There is an ASTM test for insulation hydrophobicity after heat aging. ASTM C610, the standard for expanded perlite block and pipe material, includes a water-absorption test for material first heat aged in a 600°F oven. The maximum allowable water absorption, after subsequent immersion in water for 48 hours, is 50 percent by weight. Nevertheless, when this material does absorb water and remains wet for a prolonged period of time, the chemical bonding agent is susceptible to failure, possibly leading to physical degradation of the material. However, a major benefit of this behavior is that the bonding agent is an excellent chemical inhibitor against CUI. Expanded perlite has this advantage and hence can be considered a tool in the CUI prevention toolbox for two reasons: One is its hydrophobicity and the other is that it contains a chemical inhibitor against corrosion.

As discussed above, aerogel blanket insulation and hydrophobic microporous insulations are hydrophobic in the service temperature range where the organic material, that make the insulation hydro-phobic, does not thermally decompose. Once the organics decompose, if these insulations are later exposed to water, they will then absorb the water. Later, if dried out, thermal conductivity will have permanently increased due to damage to the tiny pores that make these types of insulation so thermally effective when new. At that point, the insulation will no longer be as effective a thermal insulation as when new. Nevertheless, these two types of insulation can be valuable tools in the CUI prevention toolbox for service temperatures from ambient to the range of 400° to 600°F. For use above that temperature range where CUI prevention is a goal, the insulation manufacturers of these materials should be consulted to ensure that conditions are avoided where excessive loss of hydrophobic treatment and subsequent absorption of water might occur.

How about the effectiveness of closed cell inorganic insulation? There is only one: cellular glass insulation. Indeed, it holds very little water due to its closed cell structure and the fact that water does not pass between the cell walls. While not exactly hydrophobic, it will not absorb water. This behavior can be an important potential contributor to preventing CUI. In “Corrosion Under Insulation: Prevention Measures” (Insulation Outlook, October 2007), Dr. Hira S. Ahluwalia recommends the use of cellular glass. However, since cellular glass is fragile, it is susceptible to vibration-induced damage and can suffer from boiling water trapped between the pipe and the insulation. Therefore, its effectiveness can be limited. Further, as with many types of insulation, the boiling of water is damaging to the cellular glass structure. One point worth noting, since stress relief cracking of cellular glass typically begins to occur at service temperatures above 450° to 500°F, the manufacturer should be consulted for the best method for insulating these systems. While cellular glass insulation has some limitations in above-ambient applications, it can be considered an effective tool against CUI for applications up to 450° to 500°F.

What about corrosion inhibitors? It was already mentioned that expanded perlite contains an excellent corrosion inhibitor. Some types of calcium silicate also contains a considerable quantity of chemical inhibitor—not as a bonding agent but as an additive specifically intended to be a chemical inhibitor and thereby to prevent CUI. If calcium silicate insulation with a chemical inhibitor absorbs water, the chemical inhibitor dissolves and inhibits against corrosion.

In general, high-compressive-strength insulation provides better resistance to external loads than low-compressive-strength insulation does. These materials provide better support for the metal jacketing, limiting its compression, denting, and opening of gaps.

Expanded perlite and calcium silicate insulations both have high compressive strengths. The compressive strength for expanded perlite, per ASTM C610, is a minimum of 60 pounds per square inch (psi). For calcium silicate, the compressive strength is a minimum of 100 psi, per ASTM C533. That is the highest value of any commercially available block and pipe insulation.

On an insulated pipe or surface that is subjected to external loads, such as foot traffic, the high compressive strengths of perlite and calcium silicate will provide extra support to the metal jacketing system, helping prevent the jacketing from “fish-mouthing” at the overlaps. Fish-mouthing of the metal jacketing will allow for rainwater intrusion. By virtue of providing better support of the metal jacketing, calcium silicate and perlite insulations are considered valuable tools for CUI prevention, with calcium silicate being the strongest material available. As mentioned above, both of these materials contain a corrosion chemical inhibitor. Furthermore, expanded perlite has been included above due to its hydrophobicity.

Summary

There really is no single “silver bullet” that will prevent CUI in all circumstances and all applications. However, there are a number of different tools that can be used, each of which brings numerous features and benefits. By combining several of these tools, the facility owner can reduce the instances of CUI to the point of prevention. This may require spending more money up front on the new facility, specifying and selecting the protective jacketing system and insulation materials more carefully and thoroughly, and spending time and money maintaining the insulation system. If it is done, however, it will reduce the overall operating cost for the facility. As always, “an ounce of prevention is worth a pound of cure.”

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