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 Condensate Recovery: Vented vs. Pressurized Systems Contents: Condensate recovery systems can be classified as either vented-to-atmosphere or pressurized depending on whether condensate is recovered in an open-to-atmosphere tank (vented) or sent to a pressurized vessel/directly to the boiler (pressurized). Vented vs. Pressurized Condensate Recovery In a vented condensate recovery system, steam trap inlet pressure or a condensate pump is used to return condensate to an open-to-atmosphere collection tank for use as boiler make-up water, pre-heat or other hot water applications. In a pressurized condensate recovery system, recovered condensate is maintained above atmospheric pressure throughout the recovery process. The pressurized condensate is generally used as boiler make-up water. Since any associated flash or live steam is pressurized, this steam can be recovered for reuse in applications such as waste heat steam generators (that involve heat exchange) and cascade systems. Besides pressure, one of the major differences between vented and pressurized systems is the temperature at which condensate can be recovered. In a vented system, because condensate is vented to atmospheric pressure, the maximum recovery temperature of condensate is some value less than 100°C [212°F] due to flashing at that temperature, and subsequent heat loss during from return piping and equipment. In a pressurized system, condensate can be recovered at much higher temperatures. For example on a closed system with steam at 10 barg [145 psig], condensate can be recovered with a temperature of 184 °C [363 °F] if it is sent to a Deaerator or similar system which captures the higher heat of the higher temperature liquid. Tip Vented systems aren't limited to using trap inlet pressure. Pressure can also be equalized if backpressure is too great, in which case condensate drainage equipment such as a mechanical pump/trap assembly is balanced to the condensing equipment itself to constantly equalize with the modulation of the equipment’s pressure. When equalized with equipment, drainage will occur by gravity regardless of whether the equipment steam pressure is positive or in vacuum. Selecting Between a Vented or Pressurized System The selection between a vented or pressurized condensate recovery system should be based on a careful economic analysis relative to the gains and losses of each system, which includes the following factors: Sensitivity to backpressure Amount of equipment being drained and recovered relative to the economic and physical constraints Need for a flash recovery system For a discussion on the differences between using trap inlet pressure and a condensate pump for condensate return, please refer to: Returning Condensate and When to Use Condensate Pumps Typical Range for Vented / Pressurized Systems Since vented recovery systems are typically less costly to design and install, these will typically be used in instances where the return on investment is deemed too low to adopt a pressurized recovery system, for instance, in systems that use lower pressure steam. Pros and Cons of Vented Recovery Systems Because their configuration is much simpler, vented recovery systems typically require a much lower initial investment than pressurized recovery systems. Sizing condensate transport lines is also much easier as piping can be sized like water piping once condensate and flash steam have been separated. On the other hand, since the collection tank is open-to-atmosphere, a larger amount of energy is lost when condensate flashes to atmosphere – especially in installations where trap inlet pressure is high. The formation of vapor clouds can also have a negative impact on a plant’s work environment. Example of Condensate Recovery Vented-to-Atmosphere Condensate recovery systems that are vented to atmosphere often cost less to implement that a pressurized system, but not as much energy can be recovered. Pros and Cons of Pressurized Recovery Systems Pressurized systems involve a much greater number of design considerations than vented systems. For instance, a specialized valve must be installed to regulate the release of flash steam to atmosphere and condensate transport piping must be sized for two-phase flow of steam and condensate. However, these systems allow for a much greater percent of energy to be recovered compared to vented systems. Additionally, since flash steam is not vented to atmosphere, a greater amount of water can be recovered and reused. The absence of vapor clouds can also considerably improve a plant’s work environment. Example of Pressurized Condensate Recovery Condensate recovery systems that are pressurized often cost more to implement that a system vented to atmosphere, but also greater energy savings. Summary Table Vented Recovery Pressurized Recovery Recovered Condensate Temperature Up to 100 ºC [212 °F] Up to 180 ºC [356 °F]* System Configuration Simple Advanced Initial Costs Lower Higher Running Costs Varies Varies Piping Corrosion Significant (condensate comes into contact with air) Slight (no contact with air) Vapor Clouds Large amount (if condensate temp. is high) Minimal amount Recovery Applications Boiler make-up waterPre-heatWater for cleaning, etc. Mainly for direct feed to boiler, and Flash Steam Recovery Applications *May be higher. Limited by max operating temperature of pump and peripheral equipment. Returning Condensate and When to Use Condensate Pumps Condensate Recovery Piping Also on TLV.com Condensate Recovery PowerTrap® Steam Compressors Stop Knocking Your Condensate Return