How to deal with a leak at the outlet flange of a vacuum furnace?

This post was last edited by JIANGTAIYA007 on 2011-3-16 at 23:22. If the distance between the flange surfaces is <3mm, a box should be installed. Is it okay to tighten it if it’s >3mm? In other words, tighten it if there is room for tightening; otherwise, wrap it in a box.

Is there a leak in the flange itself, or is there a problem with the gasket? Can tightening it solve the problem? If tightening doesn’t work, consider using a clip. However, it’s relatively difficult to find clamps in places like Flange. If there are significant safety hazards that cannot be eliminated by installing plugs, it is recommended to carry out pressure relief maintenance.

The temperature at the furnace outlet is high; if there is a large leakage, operations must be stopped for maintenance and the gaskets replaced, otherwise the oil that escapes will catch fire on its own. If it’s just a leakage issue, a box can be wrapped around both furnace tubes; however, before welding, it’s necessary to measure the wall thickness of the furnace tubes and calculate the depth of penetration required for welding. It’s crucial not to weld through the tubes or to end up with a depth of penetration that is insufficient to meet the strength requirements

What do you think is likely to be the cause of the leak on your end? And what kind of gasket is being used now? I’ve also encountered cases where a pressure relief furnace flange leaked and caught fire.

Regarding the leakage at the furnace exit flange, my opinion is that operations should be halted for maintenance. The location of this issue makes it problematic; although using clamps or wrapping it up can provide a temporary solution, it will create greater risks of accidents in the long run. In places like this, hot tightening must be carried out in accordance with regulations when starting work ； Also, pay attention to whether the material of the bolts meets the requirements; 25Cr2MoVA is generally used. If the bolt material is incorrect, work must be stopped for replacement – there is no room for negotiation ； If this flange is leaking not for the first time, but keeps leaking despite repeated tightening, then the issue of pipeline stress needs to be considered; it is important to check whether the type of supports or hangers used meets the requirements. Generally, sliding supports and hangers are used in this area to accommodate the thermal expansion of the pipelines. If this is the cause of the leakage, things become more complicated – it will be necessary to recalculate the thermal expansion effects and replace the inappropriate supports or hangers. In short, material leaks in critical locations should not be handled carelessly.

Temporary measure: Plugging the leak while under pressure. Long-term measure: Relieving pressure, conducting inspections, and carrying out repairs; improving the actual process and addressing the issue at an appropriate time.

Whatever the cause of the leak, the unit should no longer be able to operate properly at this point, as there should be negative pressure at the outlet flange of the vacuum furnace – it should be drawing air inwards. Could a flash explosion occur if there is a leak? In our unit, a flash explosion happened due to corrosion and leakage of the thermocouples at the outlet of the vacuum furnace, which led to an emergency shutdown of the unit