Why Fireproofing is used?

Typically, fireproofing is designed to protect the structural steel which supports high risk or

valuable equipment. The failure point is generally considered to be 1000°F, as this is the point where steel has lost approximately 50% of its structural strength. The aim then, is to prevent structural steel from reaching 1000°F for some period of time. Tanks, pressure vessels, and heat exchangers may experience a significant cooling effect from liquid contents and so, less fireproofing protection is generally required. Some thermal insulation systems may serve a dual role as fireproofing and this is common with some pressure vessels. Piping may be insulated but it is not generally considered to be fire proofed.

Fireproofing needs to be durable to survive the rigors of every day life in the plant so that if and when a fire does occur, the fire endurance properties have been maintained and the fireproofing can be depended on to function satisfactorily. Everyday exposure may involve mechanical abuse, exposure to oil, solvents, and chemicals, and outdoor weathering for prolonged periods of twenty, thirty, forty years or more. As a coating for steel, fireproofing may provide a good measure of corrosion protection. When applied directly to steel, concrete may passivate the steel surface by providing an elevated pH. Experience has shown, however, that passivation is less than certain, especially in coastal marine environments. Corrosion under concrete fireproofing can be significant. Intumescent coatings promise better corrosion protection than concrete by virtue of their low permeability but cases of severe corrosion under fireproofing (CUF) have been reported with these materials.

Intumescent epoxies are complex proprietary materials. Concrete and some of the other materials that are used for fire protection are more familiar. The materials themselves may seem simple, but the important details of system design are often overlooked.

Risk-Based Analysis

Fireproofing is a misnomer because no material is completely fireproof. All construction materials are subject to fire damage. What we really mean is fire resistant - we seek to resist potential fire situations for a given period of time. Fireproofing is passive, built-in protection that buys time to fight the fire, shut off the fire's fuel supply and shut down the process. The aim is to minimize the overall damage incurred.

The decision to fireproof is driven by risk-based analysis. One needs to first consider the nature of the fire threat and then make an assessment of the required period of fire endurance for a wide variety of equipment including structural steel, pressure vessels, heat exchangers, pipe supports, LPG spheres and bullets, valves, and cable trays. The location of specific equipment within a process unit is important, as is a unit's location with regard to neighboring facilities.

Test Methods and required Time Rating

No fire test method is going to be typical of a real fire situation and so, there is no single correct or "best" fire test method. Standardized testing simply provides a frame of reference for relative comparisons of fireproofing materials and designs.

In the 70s, ASTM E119 "Fire Test of Building Construction Materials" was the only internationally accepted standard for investigating the performance of fireproofing materials. This test method, however, was designed to measure the fire performance of walls, columns, floors, and other building members in solid fuel fire exposures. It does not simulate the high intensity of liquid hydrocarbon-fueled fires.

Where fireproofing is required, the level of fireproofing varies with the application in the plant. Typical protection requirements for a refinery or petrochemical plant might be as follows:

• For structural steel, a facility may require a fire test rating of two or three hours. Poured-in-place concrete or gunite is most common with a specified minimum thickness of 2.0 to 3.0 inches (50-75 mm). Lightweight cementitious products may also be used.
• For steel vessels, a facility may require a fire test rating of one to two hours. Gunite applied at 1.5 to 2.0 inches (40-50 mm) may be required. Alternative fireproofing materials that provide a comparable fire resistance rating may be used, including systems that function as both thermal insulation and fireproofing.
• Plate and frame exchangers are a special concern because of the rubber gasketing material between plates. These exchangers are provided with a protective enclosure designed to prevent the exchanger from exceeding its maximum operating temperature for an hour or so. The maximum operating temperature is vendor specified and typically less than 300°F (150°C).
• Electrical and pneumatic components (including manual initiators, valve actuators, aboveground wiring, cable, and conduit) essential to emergency isolation, depressurization, and process shutdown are generally fireproofed to achieve a rating of at least 15-20 minutes. This equipment needs to function properly in the first few minutes of a fire

Source:http://www.wermac.org/materials/fireproofing.html

Introduction to Fireproofing

Fireproofing, a passive fire protection measure, refers to the act of making materials or structures more resistant to fire, or to those materials themselves, or the act of applying such materials. Applying a certification listed fireproofing system to certain structures allows these to have a fire-resistance rating.

The term fireproof does not necessarily mean that an item cannot ever burn: It relates to measured performance under specific conditions of testing and evaluation. Fireproofing does not allow treated items to be entirely unaffected by any fire, as conventional materials are not immune to the effects of fire at a sufficient intensity and/or duration.

Fireproofing is employed in refineries and petrochemical plants to minimize the escalation of a fire that would occur with the failure of structural supports and the overheating of pressure vessels. The damage that fire could potentially do very early on, could add significant fuel to the fire.

The purpose of fireproofing therefore, is to buy time. The traditional method of fireproofing has been poured-in-place concrete or gunite. Other fireproofing materials, such as lightweight cements, prefabricated cementitious board, and intumescent coatings are used to a lesser extent, primarily in areas deemed less critical and where weight reduction is a significant benefit.

Source:http://www.wermac.org/materials/fireproofing.html

The Keys to Beating Corrosion: Early Detection and Expert Monitoring

As every industry professional knows too well, corrosion is a relentless and ever-present concern for the chemical process industry (CPI). 

In fact, corrosion is the main contributing factor to:

•Increased production costs
•Health and safety risks
•Environmental issues, and
•Legal liabilities. 

With the spread of corrosion presenting a daily threat in the CPI (Chemical Process Industries), it is important to constantly inspect and monitor equipment for early signs of corrosion to prevent costly repairs or equipment failure later.

The effects of corrosion are startling:

•“As of 2014, the annual cost of corrosion in the U.S. is estimated to be about $1 trillion (about 6% of the gross domestic product).”
•“For the petrochemical sector, the annual cost is about $1.7 billion.”
•“The annual cost in the CPI is over 8% of the annual plant capital expenditures across these industrial sectors.”

Not only does corrosion cost the CPI substantial amounts of money, it also reduces the operating life of equipment, which in turn reduces the value of assets. There are many different methods to inspecting corrosion. The following methods help to locate the problems and can keep you aware of the type and location of corrosion.

Methods of detecting corrosion:

•API Visual Inspection
•Magnetic Particle Flaw Detection
•X-Ray
•Ultrasonic Inspection
•Dye Penetrants
•Remote Visual
•Bracelet Probe (CUI)
•EMAT
•Moisture Detection (CUI)
•Eddy Current
•Risk Based Inspection (RBI)

Monitoring corrosion is used to closely watch areas with signs of corrosion in all critical components. There are also several methods for monitoring corrosion.

Methods of monitoring corrosion:

•Ultrasonic Testing
•Radiographic Testing
•Guided Wave Testing
•Electromagnetic Testing
•EMAT
•Advanced Laser Testing (ALT)
•X-Ray (Computed Radiography)

Source:http://www.advancedcorrosion.com/latest/the-keys-to-beating-corrosion-early-detection-and-expert-monitoring

Cost of Corrosion Annually in the US Over $1 Trillion

Corrosion will cost the US economy over $1 trillion in 2014. That’s one of the largest expenditures NACE Corrosion Costs Study. However, this report leaves out the enormous (at least as much as direct costs) tally of indirect costs that the consumers experience from corrosion and the inflation increases since 1998.

we make, and it’s all going down the drain. The total annual corrosion costs in the U.S. rose above $1 trillion in the middle of 2013, illustrating the broad and expensive challenge that corrosion presents to equipment and materials. The most commonly quoted figure for corrosion costs is $276B in 1998 and was reported in the

From $276B to $1 Trillion: Understanding the Real Cost of Corrosion

The NACE sponsored report examines each industry in depth, providing discussions of the causes, costs, and results of corrosion, and arrived at a figure of $276B in direct corrosion costs. Indirect costs were estimated to be at least as much as direct costs.  In the 15 years that have passed since the study was released, inflation has driven both the direct and indirect costs of corrosion over $500 billion annually, totalling over $1 trillion in 2013.

At over 6.2% of GDP, corrosion is one of the largest single expenses in the US economy yet it rarely receives the attention it requires. Corrosion costs money and lives, resulting in dangerous failures and increased charges for everything from utilities to transportation and more. For a more thorough breakdown of specific corrosion costs by industry, see the NACE Corrosion Costs Study(and approximately double the numbers to have a good estimate of current values).

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About the author: Dr. Jackson is part of G2MT Labs, a company at the cutting-edge of new technologies that promise to dramatically reduce the costs (both economic and social) of corrosion.  

source:http://www.g2mtlabs.com/corrosion/cost-of-corrosion/

Is There A Cure For Corrosion Under Insulation?

Most facility managers, engineers, and maintenance and construction personnel now know that corrosion under insulation (CUI) exists and, left to its own devices, can cause serious problems and even catastrophic consequences.

It is also widely known that the results of CUI are costly. How costly? That is harder to define. Most studies on the topic involve all forms of corrosion and their associated costs without providing the individual cost of corrosion related to insulation.

What is clear, however, is that the cost of corrosion in the United States continues to increase. A study completed in 2001 by a research team of corrosion specialists enlisted by Congress titled, "Corrosion Costs and Preventative Strategies in the United States" reported the direct cost of corrosion to be $276 billion per year, with that number potentially doubling when indirect costs are also considered. Compare this to the first study conducted in 1975, which established the benchmark cost of corrosion at $70 billion. Factoring in inflation, this is actually an improvement if the data are compared to the gross domestic product, with 3.2 percent for 2001 versus 4.2 percent for the 1975 study.

CUI is typically difficult to identify because it lies hidden under insulation material, often until it becomes a serious problem. It is also expensive to inspect for or repair since that usually requires inspection by radiography, ultrasonic or other forms of inspection but in most cases requires the removal of the insulation system. This is especially true if the removal involves material with asbestos. A study done by ExxonMobile Chemical and presented to the European Federation of Corrosion in September 2003 indicated that:

• The highest incidence of leaks in the refining and chemical industries are due to CUI and not to process corrosion;
• Most piping leaks (81 percent) occur in diameters smaller than 4-inch nominal pipe size; and
• Between 40 and 60 percent of piping maintenance costs are related to CUI.

Finally, one of the largest chemical manufacturing companies in the world, E.I. DuPont de Numours and Company, estimates that the direct cost of CUI repairs and replacements well exceeds $10 million per year, which does not include normal preventative maintenance costs and indirect costs like loss of production and revenue. This is especially revealing since DuPont is known internationally as a company with world-class facility engineering, maintenance and workplace safety. Adding to this problem is the accepted belief that industrial facilities in the United States are aging, being operated and maintained by fewer personnel, and funded by reduced budgets.

It can therefore safely be determined that CUI remains a large problem for industry, even if it is not clear exactly how big the problem is today.

For CUI to form there must be two basic ingredients: moisture and warm temperatures. For iron products like carbon steel piping and equipment, oxygen is also needed. To have chloride stress corrosion (SCC) of 300 series stainless steel, there also must be the presence of chloride ions. Obviously, oxygen is fairly easy to find, but, maybe surprisingly, so are chloride ions, which are available in a great number of places from seawater, drinking and process water, and chloride chemical compounds to roadway de-icing salts. The presence of acids, acid gases, and bases like caustics and salts also can create and accelerate corrosion.

Source:http://www.insulation.org/articles/article.cfm?id=IO051101

When is it cost-effective to use thermal spray in petrochemical facilities?

Typically, thermal spray coatings are cost-effective in the petrochemical industry when you consider the cost of inspection, especially under insulation.

Even the best, most expensive paints must be inspected in 3-7 year cycles when used in CUI (Corrosion Under Insulation) conditions. Inspections most often mean scaffolding, removing all cladding and insulation, intensive inspection, including a lot if UT testing of pits, blasting, painting, re-insulating, re-cladding, removing scaffolding, etc. If thermal spray aluminum (TSA) is used instead of paint, these inspection cycles are pushed out to 25 years (ExxonMobil) to 40 years (Shell).

In this case, blasting and recoating is not required, just inspection, as it is known that a properly installed anodic TSA coating system will not corrode or “sacrifice” itself unless it is installed in such a way that the TSA has to provide anodic protection for a large cathode (unfavorable anode to cathode ratio) when an electrolyte (water or wet insulation) connects the TSA to a non-TSA coated area. We don’t do this in the petrochemical field, as we coat an entire vessel, column, or pipe (flange to flange) instead of just a tiny area and expect it to protect the entire structure.

Regarding the cost of thermal spray in a refinery, one must consider the entire erected costs (scaffolding, cladding, insulation, grit blasting and disposal, etc.) of a coating job and not just “the coating.”

Around 6 years ago, ExxonMobil reported that when the entire erected costs are considered, TSA coatings cost them 0.5%-1.5% more than liquid coatings; however, some of the paints used in CUI service have doubled and tripled in price since then. Many times, thermal spray can be applied at lower costs than wet paint when you consider factors like weather conditions, no VOC regulations, ease of or less need for touch-up, robust coatings that can be applied offsite and then installed, etc. As a pipeline applicator who did both wet paint and thermal spray coating, we charged less for thermal spray than a three-coat paint system.

Source:From James Weber of Sulzer Chemtech Tower Field Service on November 17, 2011

Case Study: Washington State Issues Record Fine in Tesoro Refinery Explosion

The Washington Department of Labor & Industries (L&I) determined that the explosion that killed seven workers at the Tesoro petroleum refinery in Anacortes, Washington could have been prevented. L&I fined the company $2.39 million for 39 “willful” violations and five “serious” violations of state workplace safety and health regulations. This is the largest fine in the agency’s history.

A heat exchanger at the refinery ruptured around 12:30 a.m., April 2, 2010, releasing hydrocarbon vapor that then ignited. The incident occurred during maintenance on the Naphtha Hydrotreater (NHT) process unit. During routine operations involving an on-line switching of unit heat exchanger feed trains, a feed-effluent heat exchanger catastrophically failed, due to high temperature hydrogen attack (HTHA), releasing a hot, pressurized flammable hydrocarbon/hydrogen mixture. Seven workers, five men and two women, died as a result. It is the worst industrial disaster in the 37 years that L&I has been enforcing the state’s workplace safety law, the Washington Industrial Safety and Health Act. 

The heat exchangers were nearly 40 years old and were subjected to extreme heat and pressure, wide temperature and pressure swings, extensive chemical exposure and a near doubling of production over the years. These are all stresses that can damage this equipment, including causing cracking.

Source:http://www.corrosionblog.com/2010/10/washington-state-issues-record-fine-in.html