--- title: "This Heater Design Flaw Is Costing You Millions: Why Heater Coils Fail in Midstream Applications" description: Heater coil failures in midstream operations are not “normal maintenance.” If your fired heater coils are rupturing every 18 months or failing every three years, that’s not bad luck — it’s a heater design problem. image: https://blog.tulsaheatersmidstream.com/hubfs/THM%202024%20Thumbnails%20(67).png --- [![Tulsaheatersmidstream](https://blog.tulsaheatersmidstream.com/hs-fs/hubfs/THM-Dec2015/Images/logo.png?width=307&name=logo.png "Tulsaheatersmidstream")](http://www.tulsaheatersmidstream.com/) - [Home](http://www.tulsaheatersmidstream.com/) - [About](http://www.tulsaheatersmidstream.com/about-us) - [Products](http://www.tulsaheatersmidstream.com/about-us#) - [SHO Heaters](http://www.tulsaheatersmidstream.com/products/sho-heaters) - [Auxiliary Equipment](http://www.tulsaheatersmidstream.com/products/auxiliary-equipment) - [Aftermarket](http://www.tulsaheatersmidstream.com/aftermarket) - [Resources](http://www.tulsaheatersmidstream.com/about-us#) - [Brochures/Literature](http://www.tulsaheatersmidstream.com/resources/brochures-literature) - [THM Academy](http://www.tulsaheatersmidstream.com/resources/thm-academy) - [Blog](https://blog.tulsaheatersmidstream.com) - [Contact](http://www.tulsaheatersmidstream.com/contact-us) # Midstream & More ## built on reputation created to serve - [Tweet](https://twitter.com/share) ## [This Heater Design Flaw Is Costing You Millions: Why Heater Coils Fail in Midstream Applications](https://blog.tulsaheatersmidstream.com/this-heater-design-flaw-is-costing-you-millions-why-heater-coils-fail-in-midstream-applications) Heater coil failures in midstream operations are not “normal maintenance.” If your fired heater coils are rupturing every 18 months or failing every three years, that’s not bad luck — it’s a **heater design problem**. At Tulsa Heaters Midstream, we regularly see operators replacing coils over and over in older heaters from competitors. The real issue isn’t the coil itself; it’s the **heater geometry, flame control, heat flux, and material selection** that create premature coil failures. Let’s break down what’s actually causing heater coil failures, and how to fix them for good. ## **Why Heater Coils Fail in Midstream Operations** In fired heaters, the **burner is the heart of the system**, but the **coil is where heat transfer happens**. If the coil fails, your heater is down — and downtime costs serious money. The most common causes of heater coil failure in midstream facilities include: - Excessive tube metal temperature (TMT) - Poor radiant box design - Flame impingement on convection tubes - High heat flux due to undersized radiant sections - Improper coil spacing - Corrosion from flue gas condensation - Inadequate metallurgy for operating conditions If your heater design is wrong, coil failures are guaranteed — no matter how many times you replace the tube bundle. ## **Elastic Failure vs. Rupture Failure in Heater Coils** Heater coil failures typically occur in two ways: ### **1. Elastic Failure (Most Common in Midstream Heaters)** Elastic failure happens when **pressure and temperature exceed the material’s design limits**. In midstream fired heaters, coils should operate within this elastic region — not near rupture conditions. Poor heat transfer modeling or incorrect tube metal temperature predictions can push coils into failure even when pressure appears normal. ### **2. Rupture or Creep Failure (More Common in Refinery Furnaces)** In refinery heater design, coils may be intentionally designed closer to rupture limits for long-term operation (e.g., 100,000-hour creep life). Midstream heaters should **never operate in rupture failure territory**. If your midstream heater coils are rupturing repeatedly, your heater design is fundamentally flawed. ## **The #1 Design Flaw: Radiant Box That’s Too Small** One of the biggest causes of heater coil failure is an **undersized radiant box**. When the radiant section is too small: - The flame cannot be fully contained - Flames extend into the convection section - Shock tubes experience extreme temperatures - Tube metal temperatures spike - Coil rupture becomes inevitable **Flame impingement on tubes is one of the fastest ways to destroy heater coils.** If the flame touches the convection tubes, you’re dramatically exceeding design assumptions — and your heater coil life drops from decades to months. ## **High Heat Flux: Too Much Fire, Not Enough Surface Area** Another major cause of fired heater coil failure is **excessive heat flux**. This happens when: - The radiant section is too small - There isn’t enough heat transfer surface area - The coil geometry is too compact - The heater design concentrates too much heat in one location High heat flux = higher tube metal temperature = faster failure. Proper heater design spreads heat evenly across sufficient coil surface area to keep tube metal temperatures within safe limits. ## **Coil Spacing Matters More Than You Think** Tightly wound coils are another hidden failure point. When coils are too close together: - Radiant heat cannot reach the back side of the tube - Heat transfer becomes uneven - The flame-facing side overheats - Localized hot spots form - Coil rupture risk increases Proper **coil spacing allows radiant energy to reflect off refractory walls** and evenly heat the entire circumference of the tube. Uniform heat transfer dramatically increases heater coil life. ## **Corrosion: The Silent Killer of Heater Coils** Not all heater coil failures come from overheating. Corrosion can destroy coils from the outside in. ### **Common Corrosion Causes:** - Low process inlet temperatures - Flue gas condensation - Carbonic acid formation on tube surfaces - Frequent heater cycling (on/off operations) - Poor post-purge procedures When flue gas moisture condenses on coils, corrosion accelerates, especially in tightly wound radiant sections. Over time, the metal thins and fails under pressure. ## **Fixing the Problem Without Buying a New Heater** If replacing the entire fired heater isn’t an option right now, there are still ways to extend heater coil life: ### **Upgrade Coil Metallurgy** Instead of replacing carbon steel coils with the same material: - Upgrade to low-chrome alloys - Consider 304 stainless steel coils for high-temperature durability Yes, stainless costs more — but replacing coils every 18 months costs far more in downtime, labor, and lost production. ### **Improve Heat Transfer Geometry (When Possible)** - Add heat transfer surface area - Reduce heat flux where feasible - Improve flame containment - Adjust coil spacing during rebuilds ### **Improve Startup & Shutdown Procedures** - Proper post-purge to remove moisture - Avoid repeated cold starts - Prevent condensation-related corrosion ## **Heater Coils Should Last Decades — Not Years** A properly designed fired heater coil should last **20 to 30 years**, not 18 months. If your facility is on a constant cycle of heater coil replacement, the problem is not your maintenance team, it’s your **heater design**. ## **Stop Paying for the Same Heater Coil Failure Over and Over** Repeated heater coil rupture is a design failure, not normal wear and tear. Tulsa Heaters Midstream designs fired heaters so that coils: - Stay within elastic failure limits - Avoid flame impingement - Maintain safe tube metal temperatures - Deliver long-term reliability - Reduce downtime and replacement costs If your heater coils keep failing, it’s time to fix the root cause — not just replace the symptom. ### **Ready to Stop Coil Failures for Good?** If your fired heater coils are rupturing, leaking, or failing prematurely, Tulsa Heaters Midstream can help you identify the design flaw and engineer a long-term solution. **Stop replacing coils. Start fixing the problem.**   [Return](https://blog.tulsaheatersmidstream.com/) ## Keep Up To Date ### Subscribe to Email Updates ### About Tulsa Heaters Midstream We are a reliable, flexible heater company that specializes in the midstream Gas Processing industry. We work with clients to fulfill all of their heater needs. Whether you need a heater designed from scratch, or you are looking for a more pre-engineered design, we are confident you will be pleased with the results. ### Follow Us - [Facebook](https://www.facebook.com/pages/Tulsa-Heaters-Midstream-LLC/1514402435461877) - [LinkedIn](https://www.linkedin.com/company/tulsa-heaters-midstream) ### Contact Us - info@tulsaheatersmidstream.com - 918-392-8000 - 1215 South Boulder, Suite 1040 Tulsa, OK 74119 Site by [CS](http://www.tulsaheatersmidstream.com/aftermarket)