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 Mitigation of Water Hammer in Vertical Flashing Condensate Transport Piping Contents: There is a common misconception that condensate return lines are solidly filled with only condensate. However, flashing condensate lines can be primarily filled with flash steam that has formed due to the sudden pressure drop of high temperature condensate discharging into the return. There is thus a two-phase flow condition (flash steam and condensate) in typical condensate lines that can create violent water hammer in the header when gravity drainage is not possible. Changes in elevation in two-phase condensate return lines are especially prone to creating severe shock from the acceleration of slugs caused by wave action within the piping. The force of these slugs can intensify as pipe size increases in diameter, due to the larger magnitude of condensate mass present. To demonstrate how water hammer can occur at the bottom of vertical risers and suggest a possible piping arrangement that may reduce or eliminate this water hammer, TLV Consulting · Engineering · Services constructed the clear piping system shown in the below video. The video is a demonstration of two scenarios: Water hammer occurring in a flashing condensate transport system which includes at least one vertical riser, a commonly seen, but not recommended, non-gravity-drainage installation. A condensate transport system incorporating a drop-down loop seal (or "DDLS"; a drop introduced in the piping immediately before the riser) to help mitigate some effects of water hammer caused by the flow obstruction of a vertical riser. Scenario 1 In the top piping arrangement, significant wave action can be seen along the horizontal run. Waves are caused by high velocity steam (represented by compressed air) moving over the surface of the liquid. When a wave grows large enough, it momentarily seals the cross section of the horizontal pipe, building a pressure wall behind it. This causes a water slug to accelerate down the line, potentially causing serious damage to piping, valves, gaskets or fittings. Additionally, in a flashing condensate line the vapor space is occupied by low energy flash steam which can collapse and generate hammer as condensate rushes in to fill the void. Scenario 2 The second, lower piping arrangement introduces a non-ideal solution to this problem: a drop-down loop seal. The ideal solution is always to incorporate gravity drainage in the flashing condensate return system design. However, when gravity drainage was not accomplished in the original design, a drop-down loop seal may help reduce water hammer. Such a configuration should be evaluated on a case-by-case basis by a professional engineer to ensure suitability and safe operation for each specific application. As the video shows, the drop-down loop seal reduces the condensate level in the pipe and minimizes the length of pipe where surging can occur. Thus, the loop seal piping arrangement can reduce surging and lower the probability of incurring dangerous water slugs. The result of such a configuration can be smoother condensate flow with lessened water hammer. Although horizontal piping is used in the drop-down loop shown to demonstrate how the interaction of vapor and liquid in the loop can promote upward flow, it is anticipated that joining two long radius elbows at the bottom of the loop with no horizontal section between them could further reduce hammer. Treat Water Hammer with Caution It should be noted that strategies for eliminating water hammer differ depending on the cause of the hammering. When water hammer occurs, plants should always ask a professional engineer to analyze the cause of the water hammer and develop an appropriate countermeasure. TLV’s steam specialists can assess water hammer and other condensate-related problems and help implement solutions that suit the needs of the plant. For more information: Contact Us Identifying Water Hammer Using a Thermal Camera Stop Knocking Your Condensate Return Also on TLV.com Stop Knocking Your Condensate Return Water Hammer: In Condensate Transport Piping Check Valves Steam Bulletin: Archive - Email Magazine