A steam trap control valve is a special valve used to automatically drain and block steam in steam systems. It promptly removes condensate, air, and carbon dioxide from the system while preventing steam leakage, thereby improving the efficiency of steam heating systems. It is widely used in industrial heating systems and steam pipelines, ensuring uniform heating of equipment and preventing water hammer.
A leaking steam trap control valve can have serious consequences for the entire steam system. When the trap fails to drain properly, condensate can accumulate in pipes or heat exchangers, causing water hammer, impacting valves, pipes, and equipment, and shortening their service life. Accumulated condensate occupies heat exchange space, reducing heat transfer efficiency, causing process temperatures to fall below target, and impacting product quality.
To avoid these hazards, the steam trap control valve must be regularly inspected and promptly repaired or replaced if leaks are detected to ensure it remains in good working order. Of course, before doing so, it is important to understand the symptoms of a leaking steam trap control valve. Only with a full understanding of the leak can we prescribe the right solution and ensure the proper functioning of the steam trap control valve.
Symptoms of a Steam Trap Control Valve Leakage
External Leakage
Steam leaks from the valve body or joints can be detected by sound and visual signs, such as a noticeable sound of steam leaking and visible steam escaping from the valve body or joints.
Internal Leakage
Direct Steam Discharge: The steam barrier function is lost, and steam is discharged directly from the inside through the condensate line. When the steam trap outlet is vented to the atmosphere after shutting down production equipment and then opening the steam trap, a rapid flow of high-pressure steam and noise will be generated at the outlet.
Back Pressure Generation: Leaking steam generates significant back pressure in the condensate return line, affecting the normal operation of other steam traps.
Abnormal “White Smoke”: A phenomenon similar to “white smoke” persists at the trap outlet, accompanied by a continuous discharge of steam, which is different from normal flash steam. Normal flash steam discharges at a slow rate, while a leak causes a more rapid discharge.
What to do if a steam trap control valve is leaking?
If a steam trap control valve is leaking, don’t panic; follow these steps to quickly fix it.
Quickly Stop the Leak
Immediately close the upstream and downstream stop valves of the steam trap control valve to cut off the steam and condensate sources and prevent further leakage. Open the bypass valve (if any) to temporarily drain the condensate to prevent water accumulation in the system.
Troubleshooting
Inspect the valve body and seat for erosion, scratches, or scaling that could cause a poor seal. Check the bonnet gasket and stem packing for age, damage, or insufficient compression. When disassembling the valve, check the valve core, seat, and strainer for debris that could affect closing.
Targeted Repair
Remove the valve core and seat and clean them with a cleaning agent to remove dirt and debris. If the gasket or packing is aged or damaged, replace the seal with a similar model and tighten the bolts evenly. If the sealing surface is severely worn, regrind or replace the valve core and seat assembly. Check the actuator for incomplete travel and recalibrate the stroke or replace the actuator.
Resuming Operation
After repairs are complete, slowly open the stop valve and observe if any leakage persists. If the system is leak-free and draining properly, resume normal operation and record the repair information.
Repair alone is not enough to extend the life of a steam trap control valve. Preventing leaks before they occur is an effective way to extend the life of the valve. Therefore, routine maintenance is crucial. If you’re unsure how to maintain a steam trap control valve, please read on.
Daily Maintenance of Steam Trap Control Valves
Regular Inspection and Cleaning
• Appearance and Connection Inspection: Inspect the exterior of the valve body weekly for signs of rust and leakage, focusing on ensuring the drain outlet is unobstructed. Also, check for loose connections to ensure the overall structural stability of the steam trap. A comprehensive inspection is generally performed once or twice a year, focusing on leaks.
• Filter Cleaning: Clean the filter regularly to prevent impurities from entering the valve and affecting proper operation. A clogged filter can hinder condensate drainage and affect system efficiency. When cleaning, remove the filter, rinse it thoroughly with clean water, and ensure no impurities remain before reinstalling it.
Component Inspection and Replacement
• Key Component Inspection: For bimetallic steam traps, monitor the fatigue of the bimetallic strip. If excessive deformation or signs of fatigue are observed, replace it promptly. Also, inspect the valve core and seat for wear. If severe wear is observed, replace it promptly to ensure a good seal and prevent steam leakage.
• Seal Replacement: Regularly replace steam trap seals to prevent leakage and performance degradation due to aging or damage to the sealing material. Function Testing and Calibration
• Automatic Vent Function Test: Test the automatic vent function quarterly to confirm timely condensate discharge and no steam escape. For frequent start-stop conditions, we recommend shortening this maintenance to biweekly, and simultaneously verifying the pressure setting matches the actual operating conditions.
• Pressure and Flow Calibration: Regularly calibrate the steam trap’s pressure setting and flow parameters to ensure it operates within the design range and avoid errors that could lead to steam leakage or unstable flow.
Lubrication and Anti-Corrosion
• Lubrication and Maintenance: Regularly lubricate and maintain the steam trap’s moving parts to maintain valve flexibility and sealing, extending its service life.
• Anti-Corrosion Protection: In humid or corrosive environments, ensure that the steam trap is treated with corrosion protection or corrosion treatment to prevent damage to components that could shorten its service life.
If you’re looking for a high-quality valve manufacturer, Newton is your ideal choice. Newton is committed to providing comprehensive solutions for steam and thermal energy systems. Beyond product services, our commitment to sustainable development encompasses everything from site surveys, energy-saving diagnostics, comprehensive product development, project implementation, operational monitoring, and system solutions. Please contact us if you have any questions.
