Recent Developments in Mechanical Insulation Technology

Gordon H. Hart

Gordon H. Hart, P.E., is a consulting engineer for Artek Engineering, LLC. He has over 35 years of experience working in the thermal insulation industry. He is an active member of ASTM committees, including Committees C16 on thermal insulation and F25 on marine technology, ASHRAE's Technical Committee on Insulation for Mechanical Systems, and the National Insulation Association's Technical Information Committee. He received his BSE degree from Princeton University. and his MSE degree from Purdue University, both in mechanical engineering. He is a registered professional engineer. He can be reached at gordon.hart®@artekengineering.com.

October 1, 2015

Many engineers and specifiers of mechanical insulation (MI) may not be aware that there have been a large number of changes and developments in standards and products in the past 5 years. When issuing project specifications, it is recommended that specifiers know what these changes and developments are so they can revise their MI specifications accordingly. Failure to do so can result in missed opportunities for improved MI performance, specifying obsolete materials or systems, or citing obsolete industry standards. These recent developments can apply to mechanical insulation, jacket, or accessory materials, to MI systems, to MI standards, and design tools. This article will attempt to capture those changes and developments.

Objectives for Using Mechanical Insulation

First, it is useful to review the objectives for using MI, and then also review other goals. The new products and systems must each meet 1 of the objectives, or help the MI system meet at least 1 objective. These objectives are as follows:

  • Reduction in Energy UseBy limiting the heat flow to or from a pipe, a duct, or an equipment piece, MI reduces energy use at the source (i.e., boiler, furnace, chiller, etc.). It can also reduce overall energy costs.
  • Process ControlBy limiting heat flow to or from a surface, MI allows the designer to limit the rate of heat flow to a known value and thereby control the temperature and pressure of the process fluid (either a liquid or gas). This is often critical to proper functioning of the process.
  • Environmental ControlsIncreasingly, designers are trying to achieve certain reductions in greenhouse gas (GHG) emissions. This usually follows the reduction in energy use, but it is not necessary equivalent. With concern over climate change, reduction in GHG emissions is increasingly the primary reason for adding MI.
  • Condensation ControlFor below-ambient fluids, condensation control is normally at least 1 of the sought objectives for adding MI. Continuous condensation can, in some instances, be a greater concern than either of the 3 previously mentioned objectives for using MI due to its potential to cause severe damage.
  • Personnel ProtectionThis objective normally refers to designing the insulation system to keep surfaces below a particular temperature so they will not burn a person who comes into physical contact with a surface (usually, but not always, 140°F). In some cases, personnel protection is the major reason for adding MI.
  • Acoustical PerformanceSeparate from thermal performance, MI can also improve acoustical performance due to its propensity to absorb sound. Noise typically originates from mechanical equipment such as fans, pumps, or compressors. With a good acoustical design, an MI system can reduce that sound below a particular design level.
  • Freeze ProtectionThere are instances where MI is required to prevent liquids within pipes from freezing due to the ambient temperature dropping below 32°F. In some applications, freeze protection is a more important objective than reduction in energy use or process control.

Other Goals for Mechanical Insulation

Following are some other goals for MI that can be important in material or system selection.

    • Meet Building Codes

 

When MI is installed inside occupied buildings, it usually is required to meet the local building code limiting flame spread and smoke-developed indices. Those codes are usually for either 25/450, in non-return air plenum spaces, or 25/50, for return air plenum spaces, per ASTM Test Method E-84.

    • Reduce Installed Cost

 

The installed cost is a sum of the material cost, cost of labor to install, contractor overhead, and ancillary costs. Materials can have different costs and some materials can be installed more quickly than others, even when using trained, skilled, and experienced craft labor (which should be the case on all projects). While everyone likes to purchase an MI system with the lowest installed cost, caution should be exercised in not simply “value engineering” the MI system, which may lower costs, but will ultimately lead to the MI not performing adequately over the system’s expected life.

    • Control Schedule of MI Installation

 

For the general contractor (GC) and, in buildings, for the mechanical contractor, it is critical to control the building schedule. Of course, this impacts the overall cost, but it can also impact the building schedule. Therefore, in cases where the contractors have high confidence in a particular MI system’s speed of installation, they may request that the insulation specifier specify that particular system.

    • Minimize CUI and Other Corrosion

 

On all MI systems exposed to the ambient, and on MI systems installed on below-ambient surfaces and located in unconditioned spaces, (which could be outdoors or indoors), corrosion under insulation (CUI) can be a major concern of the specifier. The specifier may in some cases be inclined to specify jacketing materials that seal tightly and are water resistant; in other cases he or she may specify non-water absorbing or hydrophobic insulation materials. He or she may also specify MI materials that have a chloride content below some particular value, or which meets one of the thresholds in ASTM C1617. Regardless, the specifier’s goal of minimizing CUI can influence his or her selection of MI materials.

  • AestheticsWhile MI is often located inside buildings where it is out of sight, it may sometimes be visible to people in occupied areas or even those passing by a facility outdoors. When this is the case, the specifier may specify jacketing materials of a particular luster, color, or surface finish.
  • Durability and LongevityEveryone wants their MI system to last forever. While every system has a shelf life, durability and longevity can be engineered into the MI system. For example, thicker aluminum jacketing is going to last longer than thinner aluminum jacketing. Likewise, stainless-steel jacketing will probably last longer than aluminum jacketing. The selection and specification of the materials will impact the overall MI system installed cost. However, an MI system with the highest installed cost may be more durable and hence could have the lowest life-cycle cost over some particular number of years, thus making it the preferred system.
  • Minimize Impact on Other Trades during InstallationDuring construction of either a commercial building or industrial facility, there are many different trades present. The GC must work with specialty contractors, including the MI contractor, to schedule and coordinate the work so one trade does not negatively impact another. Sometimes this is simply a matter of scheduling the different trades so they are not in each other’s way. However, the GC may also require the specifier to specify low thermal conductivity MI materials that allow for greater clearance around, or between, the insulated pipes, ducts, or pieces of equipment.
  • Health and SafetyWhile all MI materials generally meet health and safety requirements, some specifiers may decide to limit both off-gassing and emissions of thermal decomposition gasses. They may choose materials that are formaldehyde-free or have low VOCs. The GC may also require the specifier to specify low-dust emitting insulation materials if he or she has concerns about the dust negatively impacting other trades—even if the insulators are wearing protective respiratory gear.
  • Recycled ContentThere are many building projects today where the designers are trying to achieve a particular level of recycled content. When that is the case, they will oftentimes specify MI materials with a known percent recycled content (the greater, the better). As long as this does not negatively impact the MI materials’ performance or any of the other issues mentioned above, recycled content may be the deciding factor in the selection of a particular material.

New and Revised Standards, Practices, Guides, and Reports

ASTM Revisions

  • Revisions to ASTM C552, Specification for Cellular Glass Pipe and Block InsulationWhile ASTM has had a specification for cellular glass pipe and block insulation (C552), it recently made some significant revisions to include new densities of material (differentiated from one another by thermal conductivity and compressive resistance) for both block and pipe configurations. These revisions are contained in C552-15.
  • Revisions to C1126, Specification for Phenolic InsulationWhile this document has been available from ASTM for several years, ASTM Committee C16 (C16) recently revised it to include additional densities of material listed as types and grades (and differentiated from one another by thermal conductivity values). It also updated thermal conductivity values to account for new blowing agents. Specifiers should be certain to specify the most recent version: C1126-14.
  • Revisions to C1685, Specification for Pneumatically Applied High-Temperature Fiber Thermal Insulation for Idustrial ApplicationsSeveral years ago, C16 developed a new standard, C1685. The fibers from which these materials are made are inorganic and primarily silicates, made from alumna, calcium, and magnesium. The insulation covered by this specification is pneumatically applied using a wet, inorganic binder that subsequently dries after application. This specification includes insulation materials for use up to 3000°F, broken into 3 Types. These can be used at continuous temperatures up to 2000°F (1093°C), 2300°F (1260°C), and 3000°F (1649°C) for Types 1, 2, and 3, respectively. Earlier this year, C16 revised this specification to include acoustical performance and a new type of high-density material, differentiated from the other type by thermal conductivity and compressive resistance (called “crush strength” for this high-density material).
  • New Specification for Fabrication of Flexible Removable and Reusable Blanket Insulation for Hot Service: ASTM C1695-10Several years ago, C16 finalized development of a new specification: C1695, Standard Specification for Fabrication of Flexible Removable and Reusable Blanket Insulation for Hot Service. While removable/reusable insulation blankets have been fabricated and installed at industrial facilities for at least 5 decades, this is the first such ASTM specification. It can be referenced by design engineers instead of following the pattern of writing detailed specifications of their own. The insulation blankets covered by this specification may be either shop or on-site fabricated and can be used on hot surfaces up to 1000°F (538°C). There are separate requirements for outdoor and indoor applications.
  • Revisions to ASTM C1696, Guide for Industrial Thermal Insulation SystemsAfter more than 10 years of development, C16 developed the first version of C1696. While only a guide, this is a complex document, since it includes so many different MI materials. The most recent version is C1696-14ae1.
  • New Specification for Flexible Aerogel Insulation: ASTM C1728Several years ago, C16 completed development of a new specification, C1728-12, Standard Specification for Flexible Aerogel Insulation (it was subsequently revised in 2013). While this type of insulation was first commercialized a decade ago, there have been changes to the commercially available products. This specification includes insulation materials that can be used in the range of continuous exposure operating temperatures from -321°F (-196°C) up to 1200°F (649°C). These are categorized as 3 different types by maximum-use temperature as Type I: 257°F (125°C); Type II: 390°F (200°C); and Type III: 1200° F (649°C). Type III is only offered by 1 manufacturer, who had made this product by adding an opacifier (i.e., infra-red absorbing material) consisting of titanium oxide particulate. While the product containing titanium oxide is still commercially available, the manufacturer also recently started offering the product with an iron-oxide particulate as the opacifier in place of the titanium dioxide. This type of product, while being flexible, also has the advantage of having very low thermal conductivity values, lower than most other commercially available products.
  • New Specification for Aluminum Jacketing for Use over Thermal Insulation: ASTM C1729While aluminum jacketing has been used for decades over mechanical insulation, there has not been an ASTM specification for the material. C16 developed this new specification, which provides minimum acceptable performance as well as classification of different types and grades. It has been revised several times, so specifiers should be certain to reference C1729-14a.
  • New Test Method for Water Absorption by Immersion of Thermal Insulation Materials: ASTM C1763C16 developed this new test method in order to have a single test method that can be referenced by different insulation material standards. It will probably take a few years for different material standards to be revised to reference this new C1763-15 test method.
  • New Specification for Stainless Steel Jacketing for use over Thermal Insulation: ASTM C1767As with aluminum jacketing, there has not been an ASTM specification for stainless-steel jacketing. Over the past couple of years, the original C1767 has been revised, so be certain to specify the most recent, C1767-14a.
  • New Specification for Laminate Protective Jacket: ASTM C1775 To address increasing use of this type of jacket on outdoor insulated ducts and even pipes, C16 developed a new specification, C1775-14. It includes 3 types of material, depending on strength, and 3 grades of material, depending on surface emittance. There are also 3 classes, depending on the composition of the outer surface (i.e., aluminum foil, polymer film, or polymer coating).
  • New Test Method for Concentration of Pinhole Detections in Moisture Barriers on Metal Jacketing: ASTM C1789C16 developed this new test method, C1789-14, to address the need to test for pinholes in moisture barriers on aluminum and stainless-steel jacketing.
  • New Mounting Procedure for Testing Vapor Retarder Joints: ASTM C1809To address the demand for testing sheet and film-type vapor retarder joints for water-vapor permeance, C16 developed a new mounting procedure, C1809-15, using ASTM Test Method E96. Use of this mounting procedure allows for determining any water vapor leakage that might occur on taped joints.

ASHRAE and Other Industry Standards

  • The American Petroleum Institute’s (API’s) RP583In 2014, API released a new recommended practice for minimizing CUI, known as RP583 and titled Corrosion Under Insulation and Fireproofing. It is described by API as follows: “This recommended practice (RP) covers the design, maintenance, inspection, and mitigation practices to address external corrosion under insulation (CUI) and corrosion under fireproofing (CUF). The document discusses the external corrosion of carbon and low alloy steels under insulation and fireproofing and the external chloride stress corrosion cracking (ECSCC) of austenitic and duplex stainless steels under insulation. The document does not cover atmospheric corrosion or corrosion at uninsulated pipe supports but does discuss corrosion at insulated pipe supports.” It can be purchased from API’s website at http://tinyurl.com/qyn6m2p.
  • 2013 ASHRAE Handbook—Fundamentals, Chapter 23 RevisionsIn 2013, ASHRAE made a number of updates to Chapter 23 of ASHRAE Handbook–Fundamentals, including revisions regarding the use of MI on HVAC applications. These revisions include updated ASTM references as well as advice on where best to use certain MI materials and, in some cases, where to exercise caution using certain materials. Rather than list all the additions and changes, the specifier is advised to reference the 2013 version of Chapter 23 rather than the one from the 2009 or 2005 books.
  • 2014 ASHRAE Handbook—Refrigeration, Chapter 10 RevisionsIn the 2014 edition, Chapter 10 of the ASHRAE Handbook—Refrigeration was revised to provide better guidance on designing MI systems for refrigeration pipes. This includes guidance on avoiding moisture condensation and moisture penetration of the insulation system.
  • IIAR 2014 Ammonia Refrigeration Piping Handbook, Chapter 7 RevisionsIn 2014, the International Institute of Ammonia Refrigeration (IIAR) released the updated version of the Ammonia Refrigeration Piping Handbook. Chapter 7 of this version includes updated advice on MI for refrigerant pipe.
  • Revisions to the National Commercial & Industrial Insulation Standards, 7th Edition (MICA Manual)The National Commercial & Industrial Insulation Standards, 7th Edition, more commonly known as the MICA Manual, had a number of new plates added in this updated edition. It was released in 2012 by the Midwest Insulation Contractors Association (MICA). This edition contains numerous drawings, or “plates,” as they are termed in the text, which can be copied and pasted into a specification. This edition contains a new format and, more importantly, additional plates. For example, there are now several plates showing how to specify a vapor stop in below-ambient pipe insulation systems to prevent moisture intrusion longitudinally, in the direction of the pipe axis, should the vapor retarder become breached in one section of pipe insulation. This document may be purchased, as either a hardcopy or electronic from MICA’s website at www.micainsulation.org. MICA is also working on their new 8th Edition which should be released soon.

     

  • Revised NACE Standard Practice SP0198–Control of Corrosion Under Thermal Insulation and Fireproofing Materials–A Systems ApproachCUI is an age-old problem, probably as old as insulated iron pipes. To provide guidance on how to minimize the occurrences of CUI, NACE International wrote and approved Standard Practice SP0198 in 1998. In 2010, NACE updated SP0198 to provide knowledge gained since the original publication; this updated version is referred to as SP0198-2010. This document provides valuable guidance to the specifier as well as to the facility owner/operator and is available for purchase from NACE at http://tinyurl.com/prwcjly.

ASHRAE Research Projects

  • ASHRAE Research Project (RP)-1550: ASHRAE Testing of Thermal Insulating CoatingsThermal insulating coatings (TICs) have been commercially available for a couple of decades. Most consist of paint with ceramic beads added and some have aerogel beads added. After it is spray painted on surfaces, usually in several layers, and allowed to dry and cure, TICs can provide some degree of insulating value. With different manufacturers, there have been different claims about both their thermal effectiveness and their effectiveness at preventing corrosion of the steel surfaces to which they are applied. To address questions about the thermal performance, ASHRAE, through their Technical Committee 1.8—Mechanical Systems Insulation, sponsored a research project in which the contracting laboratory, R&D Services, Inc., tested 3 different commercially available TIC products. The technical report, RP-1550, can be purchased for $30 as a PDF file from the ASHRAE bookstore at www.ashrae.org.

    While some thermal resistance was measured, on pipe temperatures up to about 350°F (177°C) using several layers of TIC, none resulted in a heat-loss reduction—compared to the previously bare test pipe—of more than 60% (for comparison, only 1 inch of standard fiberglass pipe insulation will reduce heat loss by about 88% from the same temperature pipe). The TICs were found to have very low thermal-diffusivity values, which give the materials the ability to be effectively used for personnel protection up to their maximum use temperature. However, if heat-loss reduction with large energy savings—comparable to that provided by several inches of conventional MI—is required, it is generally best to use a conventional material rather than TICs. The effectiveness of TICs for corrosion protection was not evaluated as part of ASHRAE RP-1550.

  • ASHRAE RP-1356: ASHRAE Thermal Performance Tests of Chilled-Water Pipe Insulation with Water AbsorptionIn 2013, ASHRAE issued a report on RP-1356, which developed a new test apparatus and method for testing the thermal performance of chilled-water pipe insulation. The report provides previously unavailable test data on thermal conductivity as a function of water content of the pipe insulation. This report may be purchased from the ASHRAE online bookstore.
  • ASHRAE RP-1646: Measurements of Thermal Conductivity of Pipe Insulation Systems at Below-Ambient Temperature and in Wet Condensing Conditions with Moisture Ingress This research project was performed as a follow-up to RP-1356 and has now been completed. The final report has been approved by the Technical Committee 1.8. The test report is now available for purchase from the ASHRAE bookstore and gives the results of testing 6 different chilled-water pipe insulation systems on a cold pipe in a controlled, hot and humid environment over a time span of 2 months. RP-1356 and RP-1646 are the first known test reports of this type.

New Product Developments in the Past Five Years*

*List reflects new products that the author is aware of and may not contain all new product developments within the past 5 years.

  • Aluminum and Stainless-Steel Jacketing with PVdF Film Protection on the Outer Jacketing SurfacePolyvinylidene fluoride (PVdF) coatings and films provide much greater exterior chemical resistance to metal jacketing. Also, with a high emittance (greater than that
    of aluminum or stainless steel), they allow for lower insulation thicknesses when used on below-ambient pipe when surface condensation minimization is a design objective.
  • American-Made Layered Glass-Fiber Felt Pipe and Board InsulationWhile previously only made in South Korea, this pipe and board insulation is now fabricated in the United States. This insulation is made from needled glass-fiber felt mat insulation that is spiral wrapped around mandrills, of particular diameters, with a water-based inorganic binder applied to the mat surfaces, including the final outer surface; it is then oven-dried to make it rigid. The pipe insulation is made to ASTM C585 dimensions. It is also made into large boards with particular radii of curvature so as to fit around cylindrical tanks. The final product has fairly low thermal conductivity values, is rigid but not brittle, and has a fairly high compressive resistance. C16 is in the process of writing a specification for this new material.
  • Fiber-Glass Insulation with Bio-Based, Formaldehyde-Free Binder SystemWhile phenolic resin binders have been used for years in fiber glass and mineral wool insulation materials, there has been an increasing demand for formaldehyde-free binders, and even those made from non-petroleum products. While commercially available on various fiber-glass MI products, this change does not affect thermal performance in the many ASTM specifications such as C547 (for pipe), C612 (for board), or C553 (for blankets).
  • Fiber Glass Made with More Than 60% Recycled ContentDue to an increasing demand for recycled content, fiber-glass MI products made from more than 60% recycled glass are now commercially available.
  • Fiber-Glass Pipe Insulation with an ASTM C1775, Type 2 Factory-Applied JacketFor use outdoors without the need for adding a separate protective jacket, specifiers can now specify fiber-glass pipe insulation with factory-applied laminate protective jacket that meets C1775, Type 2. This jacket can be used on both below- and above-ambient pipes and ducts.
  • Flexible Elastomeric Insulation Made with EPDM RubberEthylene propylene diene monomer (EPDM) rubber has lower thermal conductivity values and greater UV resistance than standard flexible elastomeric insulation. While it has similar mechanical properties such as flexibility and resilience, its superior thermal performance and UV resistance makes this material worth specifying for particular applications.
  • Flexible Elastomeric Insulation with Overlap Seals on Longitudinal Joints and Butt-Joint Seals with Pressure-Sensitive AdhesivesTo allow for better water-vapor sealing and faster installation, flexible elastomeric pipe insulation is now available with overlap seals and butt-joint seals using a pressure-sensitive adhesive. Such seals allow insulators to install the product more quickly, thereby increasing their productivity, and to do so without concern for emission of volatile organic compounds (VOCs). VOCs can be a safety concern both due to flammability and adverse effect on laborers working in the area.
  • Microporous Insulation Available with a 5-mm ThicknessMicroporous insulation that meets the requirements of ASTM C1676-14 is now commercially available with a 5-mm thickness. This material is meant to allow for greater flexibility and thus ease of installation on pipe, and it enables its use on small-bore pipe. This makes it more suitable for a variety of industrial applications. Previously, the minimum thickness was 10mm, resulting in a less flexible sheet material.
  • PVC Fitting Covers with Foam Rubber SealsTo reduce field insulator labor when installing fiber glass with all-service jacket (ASJ) systems that typically use polyvinyl chloride (PVC) covers on the fittings, a company has developed PVC fitting covers with foam rubber seals. This product eliminates the need for the application of mastics over the ASJ-PVC joints, a labor-intensive process that has been the standard for many decades. These joints have been tested for water-vapor permeance, per ASTM E96 and C1809, and found to result in about a 25% increase in water-vapor intrusion. This is worth accounting for in a design, but it is not so great as to rule out their use. At this time, to the best of the author’s knowledge, there are not any comparable tests on ASJ-PVC or PVC-PVC joints with vapor retarder mastic, which may, when tested, prove to result in a greater than 25% water vapor intrusion.
  • Rubber JacketingThe particular new product is a flexible polymeric jacketing system. The system is manufactured from chlorosulphonated polyethylene (CSPE) which is resistant to UV, weathering, salt spray, chemicals, and ozone. This product is being specified for off-shore oil platforms and for outdoor insulated pipes on ships, all of which are exposed to weather and ocean salt spray.
  • Two-Piece Aluminum Jackets for Fittings and with Polyfilm Moisture BarriersThese fittings meet the same performance requirements of ASTM C1729-14a for roll material. Their commercial availability allows for a more consistent metal jacket system.
  • UV-Cured, Fiber-Glass Reinforced Plastic (FRP) JacketingThis new jacket product can be installed over pipe or equipment insulation in a flexible, uncured form, then exposed to sunlight or some artificial source of UV light, which cures the material into a hard, durable, chemically resistant jacket. C16 is currently working on writing a specification for this new jacket product.
  • Water-Resistant ASJWhile ASJ with exposed white Kraft paper on its outer surface has been the standard, there has been an increasing demand for a water-resistant ASJ. Water-resistant ASJ has a fourth layer consisting of a clear plastic film outer layer, which sheds water and thereby protects the Kraft paper from water exposure. To date, no change has been made to specification ASTM C1136 (i.e., the specification for vapor retarders) to account for this new ASJ.

New or Updated Software Design Guides

NIA Resources

  • Mechanical Insulation Education & Awareness E-Learning SeriesThis free online training course teaches experts and novices about the benefits of MI as well as Design Objectives and Considerations, and Maintenance. NIA has also created tests so that companies can easily incorporate this course into their existing training or educational programs. The course is available at www.wbdg.org/education/nia01.php.
  • Mechanical Insulation Design GuideThe Mechanical Insulation Design Guide (MIDG) is part of the Cloud-based Whole Building Design Guide (WBDG). The MIDG is another design tool available at no charge that helps the designer better understand how to design mechanical insulation systems. It can be accessed at www.wbdg.org/design/midg.php. The MIDG has several sections. The first is on the Design Objectives, and this section includes calculators for estimating condensation control insulation thicknesses on below-ambient systems, energy savings, financial savings, time for water in an insulated pipe to freeze, personnel protection, insulation thickness, and temperature drops for both air-handling ducts and hydronic piping. There are also sections on Materials and Systems, Installation, Design Data, Specifications, E-learning Modules, Resources, Case Studies, and a Glossary. Web-based and free to use, the MIDG helps assure that designs are performed by well-informed engineers.

Other Software Programs

  • New Computer Program for Performing Hygroscopic Analyses of Insulated Pipe and EquipmentThis software was developed a few years ago by a German company for the modeling of simultaneous heat and moisture transfer in building walls and ceilings.
    The purpose of developing this software was to address moisture problems prevalent in building envelopes that can lead to mold growth and structural wood member deterioration. While developed as either a 1- or 2-dimensional program, this software can be a valuable tool to model below-ambient pipe insulation, such as that on refrigerant piping. Since all refrigerant pipe insulation, including that on cryogenic service, must eventually become full of water or ice (unless it is located in Antarctica or the North Pole), the question invariably becomes, “How long will a particular insulation system last?” Assuming a quality specification, quality workmanship, and knowledge of insulation material and vapor-retarder material properties, one can model a refrigerant pipe in a given geographic location for many years. If the user defines a maximum amount of moisture intrusion into the insulation material that is deemed acceptable (e.g., 50% by weight), then he or she can calculate how long it will take for that intrusion to happen. Thus, the user can predict the expected life of the insulation system. If the user arrives at an unacceptable answer, he or she can select a different insulation material, with a lower water-vapor permeability, and/or a different sheet-type vapor retarder with a lower water-vapor permeance, then re-run the program for that geographic location. Of course, if the user changes the geographic location (i.e., he or she uses weather data for Boston, Massachusetts instead of weather data for Houston, Texas), he or she could find a significantly different life expectancy for a given pipe operating temperature and a given pipe insulation system. This software is call WUFI and is available at www.wufi.de/en/ for purchase.

Conclusions and Summary

Since 2010, there have been a number of new mechanical insulation products and systems developed in North America. Some are modifications to previously commercially
available materials, and some are completely new. Additionally, ASTM has developed several new standards and revised a number of others. It is recommended that these be
referenced in all project specifications rather than the older versions. Mechanical insulation guides have also been developed or revised, including the MIDG, certain ASHRAE handbook chapters, the MICA Manual, and the IIAR Ammonia Refrigeration Piping Handbook chapter on Refrigerant Piping; these guides can be valuable for the mechanical insulation specifier.

NACE International has also revised its standard practice on corrosion under insulation and API has written a new recommended practice; these documents can also be valuable for the mechanical insulation specifier concerned with reducing incidents of CUI on his or her projects. In summary, a specifier of mechanical insulation systems has numerous new products, systems, specifications, test methods, test reports, guides, and practices at his or her disposal. Ignoring these new developments and failing to take note of advances in mechanical insulation technology puts the quality of his or her work—and thus his or her employer and clients at risk. Using the aforementioned resources and staying abreast of new developments and updates is the best way to ensure the integrity of all projects and systems.