Steam Theory 1. Basics of Steam What is Steam? Principal Applications for Steam Types of Steam Flash Steam How to Read a Steam Table 2. Steam Heating Heating with Steam Steam Heating Mechanism Overall Heat Transfer Coefficient What is Vacuum Steam? Tracing the Causes of Heat Maintenance Issues 3. Basics of Steam Traps What is a Steam Trap? The History of Steam Traps #1 The History of Steam Traps #2 How Mechanical Traps Work: A Look at their Mechanism and Merits How Disc Traps Work: A Look at their Mechanism and Merits How Bimetal-Type Thermostatic Steam Traps Work: A Look at their Mechanisms and Merits 4. Steam Trap Selection Steam Trap Selection: How Application Affects Selection Steam Trap Selection: Understanding Specifications Steam Trap Selection: Safety Factor and Life Cycle Cost Traps and Orifices Part 1 Traps and Orifices Part 2 Casting vs. Forging Applications of Different Types of Steam Traps Don't Get Steamed : Selecting Steam Trap Design Understanding Steam Traps Compare Two Fixed Orifice Venturi Products to a Variable Orifice Free Float Steam Trap 5. Steam Trap Problems Is My Trap Leaking Live Steam? Temperature Control Trap Precautions Trap Installation Orientation Trap Back Pressure Double Trapping Group Trapping Steam Locking Air Binding My Steam Trap Is Good - Why Doesn't It Work? 6. Steam Trap Management Introduction to Steam Trap Management Steam Trap Losses - what it costs you A Guide to Steam Trap Testing Implement a Sustainable Steam Trap Management Program Impact Plant Performance by Improving the Steam System 7. Water Hammer Water Hammer: What is it? Water Hammer: The Mechanism Water Hammer: Cause and Location Water Hammer: In Steam Distribution Lines Water Hammer: In Equipment Water Hammer: In Condensate Transport Piping Identifying Water Hammer Using a Thermal Camera Mitigation of Water Hammer in Vertical Flashing Condensate Transport Piping Stop Knocking Your Condensate Return Steam Trap Management: Do Something; Anything. Please! 8. Risk Mitigation Steam System Optimization and Risk Mitigation Risk Based Methodology for Industrial Steam Systems Why Bad Things Happen to Good Steam Equipment Beware of the Dangers of Cold Traps Steam System Winterization: How to Protect Your Plant 9. Steam Quality Wet Steam vs. Dry Steam: The Importance of the Steam Dryness Fraction Separators and their Role in the Steam System Clean & Pure Steam Temperature Problems Caused by Air Removing Air from Steam Equipment Air Vents for Steam Steam Quality Considerations 10. Steam Distribution Best Practices for Condensate Removal on Steam Lines Installation Tips for Steam Traps on Steam Mains Erosion in Steam and Condensate Piping Corrosion in Steam and Condensate Piping Allocate New Plant Focus to Steam System Design—Part 1 11. Condensate Recovery Introduction to Condensate Recovery Returning Condensate and When to Use Condensate Pumps Condensate Recovery: Vented vs. Pressurized Systems Condensate Recovery Piping What is Stall? Methods of Preventing Stall Cavitation in Condensate Pumps Steam Heat Exchangers are Underworked and Over-Surfaced Allocate New Plant Focus to Steam System Design—Part 2 Optimize Reboiler Performance via Effective Condensate Drainage Vent Away Condensate Pump Frustrations in a Flash 12. Energy Efficiency Tips to improve steam plant efficiency Advice on Winter Preparation for Steam Systems Insulating Traps Steam Compressors Why Save Energy? Management Strategies for Conserving Energy Recovering Steam Clouds and Waste Heat Waste Heat Recovery Boiler Energy Saving Tips Steam Line Energy Saving Tips Steam-Using Equipment Energy Saving Tips Preventing Steam Leaks Handle Steam More Intelligently Optimize the Entire Steam System Use Available Data to Lower System Cost 13. Compressed Air / Gas Removing Condensate from Compressed Air Preventing Clogging of Air Traps Air Compressor Energy Saving Tips Improving Compressed Air Quality and Countermeasures Against Leaks 14. Other Valves Types of Manual Valves Bypass Valves Check Valve Installation and Benefits Pressure Reducing Valves for Steam Air Binding Contents: What is Air Binding? "Air binding" is a problem that typically occurs in steam, air or gas traps where a non-condensable gas such as air causes the trap valve to remain closed, impeding condensate discharge. This problem occurs because steam/air/gas traps are automatic valves designed to: Smoothly remove condensate Prevent the discharge of the steam/air/gas, respectively (i.e. the fluid being transported) So the occurrence of air binding simply means that the operating mechanism of the trap is functioning properly. Issue of Air Binding in a Process Unlike steam, air does not easily condense, and can remain trapped within the body of a steam/air/gas trap, causing a problem known as air binding. The mechanism behind air binding is similar to steam locking. The main difference between the two problems is that with steam radiation heat loss causes a decrease in pressure/temperature of the steam which eventually causes it to condense, allowing condensate to be slowly discharged. Air, on the other hand, does not condense, leaving the problem unresolved. Difference Between Air Binding and Steam Locking When air binding occurs, the problem does not resolve itself on its own because air does not condense from radiant heat loss. When steam locking occurs, the problem may resolve itself on its own because steam can condense through radiant heat loss. Note: The problem may still reoccur at the following discharge cycle. Countermeasures for Steam Traps Countermeasures against air binding differ depending on whether the problem occurs in a steam trap or an air/gas trap. For steam traps, the problem is typically fixed by installing a steam trap that is equipped with a built-in automatic vent to discharge non-condensable gases such as air. This is possible because the air and other non-condensable gases are not being used by the process. Rather, they are unwanted fluids mixed in with steam. Since piping is typically at ambient temperature at start-up, many air vents use an opening/closing mechanism that is based on the temperature difference between air and steam: the air vent valve remains forcibly open at cooler temperatures to allow air to be discharged out of the system, and closes when warmed by steam to prevent the unwanted discharge of steam. Many steam systems use traps fit with either an X-element or bimetal strip to allow non-condensable gases such as air to automatically move downstream of the trap, allowing for smooth condensate discharge. Automatic Air Venting Mechanisms Air Venting Using an X-Element The opening and closing of an X-element air vent is based on the expansion and contraction of an internal element that contains either an alcohol based mixture with a boiling point lower than that of water, or a bimetal element that bends below 100 °C. Air Venting Using a Bimetal Strip The bimetal strip remains contracted when cold, keeping the valve seat open and allowing air to be rapidly discharged. Countermeasures for Air/Gas Traps A different method is usually used to resolve air binding problems that occur in air or gas traps because the air/gas typically causing the problem is also being used for the process and should not be wasted. In this case, the air or gas should be returned to a larger space that can receive it by installing a pressure-balancing line. This should allow condensate to be properly discharged through the trap. Pressure balancing lines are an extremely common and effective way of resolving air binding problems in these types of traps, and further information on their installation should be available in your air/gas trap instruction manual. Adding a Pressure-balancing Line to an Air Trap When installing a pressure-balancing line, it is important to make sure that pressure is well-balanced. The higher density condensate should remain in the lower part of trap, while the lower density air/gas should remain in the higher part of the trap so that it can be returned to the process. This configuration should allow for the smooth discharge of condensate. Pressure-balancing Line Configuration Tips Pressure balancing lines require a very precise setup. If the line is not well balanced and pressure rises too much, backflow of air/gas can occur, making the problem worse than before. Similarly, pressure loss in a pressure-balancing line that has a too small diameter can prevent air/gas from being properly transported out of the trap. Issue with High Back Pressure of Pressure-balancing Line If the line is not well balanced, backflow of air/gas can occur, making the problem even worse that before. Issue with Diameter of Pressure-balancing Line The diameter of the pressure balancing line must be large enough to allow for sufficient removal of the trapped air/gas. It's also important to note that a pressure-balancing line is often not required with air/gas traps installed at the bottom of a vertical line because the liquid and gas should be able to freely move about, limiting problems from air binding. Additional Note Whether your system uses steam traps or air/gas traps, piping should always be configured in a way to allow for smooth and rapid discharge of condensate. In general, traps should not be installed at the top of vertical sections of piping, and inlet piping should be as short as possible and have a diameter as large as possible to reduce chances of air binding. For assistance with resolving air binding, contact a TLV engineer today. Contact Us Steam Locking My Steam Trap Is Good - Why Doesn't It Work? Also on TLV.com Free Float® Steam Traps for Process Use Free Float® Steam Traps for Steam Mains and Tracer Lines Steam and Condensate Training Seminars Engineering Calculator