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 Water Hammer: The Mechanism Contents: Water hammer generated in steam and condensate recovery systems is usually classified into two main categories: caused by high-speed condensate slamming into piping, etc. caused by the sudden condensation of steam, which produces walls of condensate that crash into each other Water Hammer caused by high-speed condensate Radiant heat loss causes condensate to form inside steam transport piping. Steam flowing at high speeds within this piping draws this condensate forward and causes ripples. From this turbulence, slugs of condensate gradually begin to form and are carried along with the steam. This is similar to the high waves formed by very strong wind. In this case, water hammer occurs when these slugs of condensate strike a curve or valve as they travel through the piping. Water Hammer caused by the sudden condensation of steam When steam loses its heat, it turns into condensate, whose specific volume is more than 1000 times smaller than that of steam. So when steam comes into contact with colder condensate and condenses, its volume is instantly reduced to next to nothing. During the condensation process, the space occupied by the steam momentarily becomes a vacuum, and the condensate inside the piping surges toward this vacuum. This is the second type of water hammer, known as "steam-induced" water hammer, which occurs when these surging walls of condensate crash into each other. As such, it is dangerous for piping to contain a mixture of cold condensate and steam. This is the norm, however, in condensate recovery piping and similar systems, which makes this type of water hammer difficult to prevent. Although this type of water hammer created from steam pockets is limited to condensate recovery systems, water hammer also occurs in steam distribution lines and steam-using equipment when condensate is not drained quickly ("condensate-induced" water hammer). Powerful impacts can occur in both of the above-mentioned types of water hammer; however, these impacts occur with greater frequency in the case of steam-induced hammering. The video above is actual footage captured by TLV of steam-induced water hammer occurring in clear condensate return piping. This type of water hammer can happen when steam pockets collapse in condensate recovery lines. How does condensate temperature affect water hammer? Previously, it was believed that the lower the temperature of the condensate, the greater the resulting water hammer. However, experiments carried out at TLV revealed a surprising fact. It was discovered that the most severe impacts from water hammer occur when the condensate is at a temperature only slightly lower than that of the steam. More specifically, at a steam temperature of 100 °C, it was found that condensate between 70 °C and 80 °C caused water hammer on a larger scale than condensate between 50 °C and 60 °C. In fact, the impact caused by water hammer can be mathematically calculated, and the results of such calculations show a strong relationship between the intensity of the water hammer and the volume of the condensing steam (= called ‘pockets of steam’). Taking a closer look at the graph, three zones of condensate temperatures can be identified: On the left side of the graph, steam comes into contact with cold condensate and immediately condenses. In this case, condensation happens on the scale of tiny steam bubbles and large 'pockets of steam' cannot form, hence only small water hammer occurs. The middle section is of greater concern. Due to the relatively small temperature difference of 20-30°C between the condensate and steam, the steam does not condense all at once, but gradually. As the condensation process slowly occurs, it will reach a point where suddenly all the steam condenses. The delay created between the time the steam comes into contact with condensate and the time it suddenly condenses is what allows the formation of bigger pockets of steam, and hence bigger water hammer. On the right side of the graph, steam comes into contact with condensate of the same temperature. In this case, it does not instantly condense and water hammer does not occur. This can be confirmed from the fact that water hammer does not appear right at the outlet of a steam trap where saturated condensate coexists with flash steam of the same temperature. We know that condensate between 70°C and 80 °C causes an increase in size of the 'pockets of steam' and with this the most severe water hammer. So what triggers the process? Find out in Water Hammer: Cause and Location. Having problems with water hammer? Our steam specialist engineers can help. Contact Us Water Hammer: What is it? Water Hammer: Cause and Location Also on TLV.com Steam Trap Survey Steam System Analysis Maintenance and Installation Services Steam and Condensate Training Seminars Free Float® Steam Traps for Steam Mains and Tracer Lines Engineering Calculator Steam Bulletin: Archive - Email Magazine