Vacuum System Troubleshooting
HOW WE CAN HELP?
Let us at Erivac, together with our partners PESINT and KOERTING, help you find solutions to your problems in your most challenging process applications.
We are a leading supplier of a large and high-quality range of process equipment such as ejectors, thermocompressors, vacuum systems, wet scrubbers, aerators and agitators, welded heat exchangers, cooling towers, refrigerant coolers, steam traps and more.
In order to get the most out of these equipment we can also provide services such as:
Process and Energy Optimization
Steam and Condensate System Diagnosis
Waste Energy Recovery
Pulp Drying, Paper and Tissue Machine Diagnosis and Optimization
Vacuum System Diagnosis and Troubleshooting
Combining our broad knowledge with high-end technical solutions and equipment, we can help you find process solutions with higher availability, less maintenance necessity and lower energy consumption.
Vacuum System Troubleshooting and
Diagnosis
Erivac can, together with Koerting, provide diagnosis and troubleshooting of steam ejector vacuum systems. A well-performing vacuum system operating close to design conditions ensures reliable, trouble-free and energy-effective operation. With time, wear will occur, performance will be reduced and energy consumption will increase. We can help you find solutions for these problems and solutions to return operation to design point with better energy efficiency.
Troubleshooting requires isolating the issue to motive steam supply, cooling water, process air leaks, or internal wear. The most critical first step is to check for system air leaks and verify that the motive steam is completely dry and delivered at the correct pressure.
Motive Steam Issues
- Symptom: Low vacuum, surging, or ejector failing to break the sonic shock wave.
- Causes: Wet steam, incorrect pressure, or eroded nozzles.
- Troubleshooting Steps:
- Check steam quality: Ensure lines are properly insulated and install a steam separator with a working trap directly before the inlet. Wet steam causes severe erosion to the nozzle throat and drastically reduces capacity.
- Verify pressure: Ensure motive steam pressure exactly matches the design specifications. Low pressure drops the compression ratio; excessively high pressure chokes the diffuser.
- Inspect for wear: Measure the nozzle throat diameter. If it is more than 15% oversized relative to the nominal size (often due to erosion or galvanic corrosion of the threads), replace the nozzle.
Condenser & Cooling Water Problems
- Symptom: High inter-stage pressure, overloading of the subsequent ejector stage, or surging.
- Causes: Fouled condenser tubes, warm cooling water, or flooding.
- Troubleshooting Steps:
- Check water flow: Verify the inlet temperature and flow rate. An excessive temperature rise or high cooling water temperature means you need to increase flow.
- Check for flooding: Ensure interstage condensers are draining properly. If the barometric leg is blocked, condensate will back up and kill the ejector vacuum.
- Inspect internals: Clean fouled tubes and verify that water spray nozzles are not eroded or clogged.
Air Leaks & Overloading
- Symptom: Gradually degrading vacuum levels, requiring higher loads than the system was designed for.
- Causes: Process air in-leakage, non-condensable gas overload, or leaking isolation valves.
- Troubleshooting Steps:
- Isolate the system: Close the suction valve to the vacuum process to see if the ejector alone pulls a deep vacuum (the “deadhead” test). If it does, the leak is in your process equipment.
- Check for leaks: Inspect flanges, valves, and expansion joints under vacuum for air ingress.
- Monitor load: Ensure you haven’t introduced unexpectedly high non-condensable gas loads (such as steam leaks or light hydrocarbons) that overwhelm the first stage.