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 Removing Air from Steam Equipment Contents: As seen in the article discussing Temperature Problems Caused by Air, removing air from steam equipment is essential to effectively use steam. The following article will first cover the relationship between the densities of air and steam, and then discuss how this affects the positioning of air vents in steam-using equipment. Which is Heavier, Air or Steam? The average molecular weight of air is 29, which means that 1 mole weighs 29 grams. The molecular weight of steam (water) is 18, which means that 1 mole weighs 18 grams. Therefore, under standard conditions* 1 mole of steam (water) is lighter than 1 mole of air. However, operational conditions do not limit themselves to standard conditions. The densities of steam and air vary greatly according to the following factors: The steam:air ratio The pressure The temperature * STP (Standard Temperature and Pressure): 1 atm, 0°C (273.15 K, 32 F) Effect of Pressure and Temperature on the Density of Air/Steam For example, as the above graph shows, air is heavier than steam at temperatures lower than 162°C (324 F), but lighter than steam at temperatures higher than that. However at 2.0 MPaG (290 psig), the relationship between the densities of steam and air changes at 188°C (370 F). The densities of steam and air clearly vary depending on the temperature and partial pressures of the mixture. When configuring a system for proper air venting, it is important to realize that air vents cannot simply be installed on the top or bottom of equipment because of the varying densities of steam and air. Proper air venting can thus require more than one air vent depending on equipment configuration. From Where Should Air Be Removed on Equipment? In steam-using equipment, the air filling the steam space is pushed along by the flow of steam at start-up. Since heating begins when steam enters the equipment, it is critical that all the air be completely discharged at this time. For a simple steam space configuration, such as the one illustrated in the animation below, a steam trap with an automatic air venting function is often suitable enough for air discharge. However, particular care must be taken for equipment with complex steam space configurations or equipment that uses a siphon pipe because air has a tendency to build-up in these types of equipment even if a steam trap with an automatic air venting function is used. In such cases, the use of a specially designed air vent for steam systems is recommended. Such an air vent should be installed in stagnant flow or collection areas where air is likely to be pushed. Air vents for steam are a type of automatic valve with a configuration similar to that of thermostatic steam traps: the valve opens and closes in response to the difference in temperatures of the steam and the air. For more information on air vents for steam, please read the article: Air Vents for Steam Temperature Problems Caused by Air Air Vents for Steam Also on TLV.com Air Vents Steam and Condensate Training Seminars Engineering Calculator Steam Bulletin: Archive - Email Magazine