Heater coils are the workhorses of fired heaters in midstream plants. Whether in natural gas facilities, cryoplants, or frac plants, they endure extreme conditions to ensure fluid processes run smoothly. However, when issues arise, a failing coil can lead to costly downtime and potential safety hazards. Why do heater coils fail, and what can we do to prevent it?
At Tulsa Heaters Midstream, we understand the intricacies of coil performance. With decades of experience engineering reliable, efficient heaters, we want to share key insights into why heater coils fail and how to extend their lifespan reliably.
The Stakes Are High for Heater Coils
To understand coil failure, consider the operational environment of a fired heater. Inside, temperatures can reach 2200°F, with pipes carrying combustible fluids under pressures as high as 1000 PSIG. If a design flaw or operational misstep occurs, these extreme factors create the potential for coil damage or failure that can significantly impact performance or safety.
Yet, with the right design and operational practices, heater coils can last decades. Below, we break down the main causes of coil failure and how proper engineering can address these challenges.
1. Improper Coil Spacing
Why It Matters
Radiant coil spacing plays a critical role in performance and longevity. Coils in the radiant section of a heater are subject to intense radiation from the flame. If the spacing is too tight, only a limited portion of the tube surface absorbs radiation, causing uneven heat distribution and localized overheating. This concentration of thermal stress can lead to premature coil failure.
The Solution
Adhering to standards like API 530 and 560, Tulsa Heaters Midstream incorporates a "2D" spacing rule (two times the coil diameter) in our heater designs. By ensuring proper gaps between helical coils, we allow radiation to evenly reach all tube surfaces. This uniform heat distribution prevents stress concentrations and significantly reduces the risk of burnout or failure.
2. High Radiant Flux Near the Flame
Why It Matters
The proximity of the heater flame to the coil surface can have a profound effect on coil integrity. When coils are positioned too close to the flame, they are exposed to excessive radiant flux. The result? Accelerated material degradation and coil deformation in sections closest to the heat source.
The Solution
At Tulsa Heaters Midstream, we design radiant sections with precision to maximize heat transfer efficiency while protecting coils from excessive thermal loading. By optimizing the burner design, spacing, and overall heater geometry, we ensure that radiant flux remains within safe operating thresholds.
3. Condensation and Corrosion in Regen Heaters
Why It Matters
Regen heaters, which cycle on and off frequently, are particularly prone to condensation issues. During shutdowns, the flue gas inside the heater cools, leaving behind moisture. This moisture can form carbonic acid, accumulating at low points in tightly wound coils. Over time, this acid eats into the metal, leading to corrosion and potential tube leaks.
The Solution
The key to combating condensation lies in the design philosophy. Tulsa Heaters Midstream prioritizes loosely wound coil configurations, which provide space for moisture to dissipate and reduce corrosion risks. Additionally, our designs incorporate proper drainage and venting features to minimize the buildup of acidic condensation.
4. Overloading the Radiant Section
Why It Matters
Efficiency is crucial in midstream plants, where operators often aim to maximize energy input into compact heater footprints. However, attempting to fit too much energy into too small of a radiant section can overload the coils within that area. This "overpacking" results in localized temperature spikes, particularly where the flame exits and makes contact with the tubes, leading to coil failures at these critical points.
The Solution
Our engineering team designs radiant sections with care, ensuring they are appropriately sized for the required heat duty. By creating spacious radiant sections, we avoid the risks of overloading and ensure that the entire system operates with efficiency and safety in mind.
Best Practices for Ensuring Long Coil Life
Extending the life of heater coils starts with smart design, but proper operation and maintenance are equally important. Here are some best practices to keep in mind:
- Follow Operational Guidelines: Operating heaters within their design temperature and pressure ranges minimizes unnecessary strain on coils.
- Invest in Preventive Maintenance: Routinely inspect coils for signs of wear, hotspots, or corrosion. Early detection can prevent minor issues from escalating into major failures.
- Partner with Experts: At Tulsa Heaters Midstream, we provide tailored solutions for your specific process requirements, helping you strike the perfect balance between performance and durability.
Tulsa Heaters Midstream Is Here to Help
At Tulsa Heaters Midstream, we bring unparalleled expertise to the midstream industry. We’re not just about equipment—we’re about solutions that keep your operations running safely and efficiently. Our team designs heaters that prioritize reliability while addressing the challenges unique to your applications, from radiant section sizing to coil spacing and beyond.
If you want to learn more about how our designs can help mitigate coil failures, we’ve put together a detailed video covering this topic on our YouTube channel. Don’t miss out on the insights from our experts that could help save time, money, and resources at your facility.
Equip your operation with the tools for long-term success. At Tulsa Heaters Midstream, we’re here to make that vision a reality.