JM partnered up with Inspectioneering to host a live webinar panel discussing Mechanical Integrity Considerations for Your Insulation System. Panel experts, Greg Alvarado (Inspectioneering), and Marybeth Jones (Johns Manville) and Scott Sinclair (Johns Manville) discussed information pertaining to key considerations for insulation systems, ranging from material selection to how risk-based inspection (RBI) plays a role in ensuring optimized system performance and mechanical integrity. If you weren’t able to make it to this panel discussion below are 4 key take-aways, or you can watch the recording.
1. Knowledge loss is one of the biggest challenges the refining and chemical processing industries are facing when it comes to insulation: Loss of knowledge base is one of the most significant challenges we see in the insulation field in the refining and petrochemical industries Many of the technical experts and seasoned industry professionals have retired in the last 5-10 years. Beyond that, it’s difficult to attract younger people into the insulation business. This resulting in a major loss of the historical knowledge base formed over the last 40-50 years, as well as a skilled labor shortage. This manifests in a variety of ways from copying and pasting old insulation specifications, to lacking QA/QC processes, to an overall poor understanding of when and where to insulate.
These problems are further compounded by the fact that insulation is usually one of the last things that happens on a project. By the time the system is ready to be insulated, projects are often behind schedule and over budget, so there is a lot of pressure to save money and get it done faster. This can lead to value-engineered systems that are hastily installed, resulting in insulation materials and/or poor-quality installations that aren’t fit for the rigors of the application.
Educational programs can help correct the issues that arise from this loss of knowledge, as well as a robust inspection and maintenance program that can ensure the system is operating optimally.
2. There are three codes and standard documents that can help when it comes to designing systems to fight corrosion under insulation (CUI)
a. API RP 583, Corrosion Under Insulation and Fireproofing covers design, maintenance, inspection, and mitigation practices to address external CUI and CUF as it applies to pressure vessels, piping, storage tanks and spheres. It examines the factors that affect the damage mechanisms and provides guidelines for preventing external corrosion or cracking under insulation, maintenance practices to avoid damage, inspection practices to detect and assess damage, and guidelines for conducting risk assessments on equipment or structural steel subject to CUI/CUF.
b. NACE SP0198 - Control of Corrosion Under Thermal Insulation and Fireproofing Materials provides the current technology and industry practices for mitigating corrosion under thermal insulation and fireproofing materials. This standard practice contains sections on corrosion mechanisms, mechanical design, protective coatings, insulation materials, and inspection and maintenance.
c. ASTM STP 880 - Corrosion of Metals Under Thermal Insulation reviews the causes and factors affecting the occurrence and rate of CUI, the field experience with insulation types and control measures, including the use of coatings; specifications; system design; and inspection.
3. Recent advancements in insulation technology in recent years: While it may seem like insulation has remained the same for decades, this isn’t entirely accurate. Insulation technology has advanced from new insulating technology to new methods to improve
a. Spacers and drain ports: While these have been relatively common in Europe, spacers between the pipe and the insulation and between the insulation and the jacketing have become more common throughout the US. Additionally, we’re seeing an increase in specifying drain plugs at low points in the systems. The purpose for the spacers is to keep wet insulation off the pipe, and the drain plugs allow an escape for any water that has entered the system.
b. Water-resistance: There’s been a decided increase in hydrophobic treatments and designs. While water resistance is not a silver bullet solution for water ingress or CUI, it can help slow water ingress. Evidence has shown that over the life of the system, the chemical makeup of base material for the insulation can be just as important, if not more-so, than the water-resistance.
c. Corrosion inhibitors: Corrosion inhibitors are part of a formulation change that took place in JM’s calcium silicate (cal sil) in the early 2000s. While early cal sil was known to be relatively corrosive on pipe systems, JM’s calcium silicate Thermo-1200® incorporates the XOX Corrosion Inhibitor® that significantly reduces the corrosive potential of the insulation, making it one of the least corrosive insulations on the market today. This same corrosion inhibitor is also part of JM’s expanded perlite, Sproule WR-1200®
4. Corrosion Inhibitors can have a positive impact on your risk-based inspection (RBI) plan
a. With API RBI methodology there is a decision tree/algorithm that designers can use to calculate a corrosion rate. Considerations such as material construction, temperature, environment, etc. are used to calculate a corrosion rate or a crack susceptibility in the metal beneath the insulation. That corrosion rate is adjusted by the characteristics of the insulation. So, if a material were to have a corrosion inhibitor, it should be considered in this calculation and it can positively impact the corrosion rate of the equipment. It is also important for engineers using this methodology to ensure that the number they use for the corrosion rate complies with good engineering practices and logical justification. It is important to clearly document your logic, so you can explain why you used a specific corrosion rate number.
