Leakage in pneumatic control valve
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There is a leak at the gasket of the pneumatic control valve, and it’s no longer possible to tighten the gland further. Since it’s a project abroad, graphite packing is hard to obtain – is there any way to solve this problem? Could everyone please suggest a solution? The medium flowing through the pipeline is liquefied gas
For liquefied gas, using asbestos rope packing should be fine.
Is it hard to find graphite packing? You didn’t press it properly when changing the packing.
What other materials do you have? The asbestos packing mentioned upstairs will work too.
When I opened it, I saw that it contained PTFE packing. Can I remove the existing PTFE packing and wrap it again with asbestos rope? And what should I do with the asbestos rope? Would soaking it in engine oil work? Wrap it on directly. Thank you!
You can’t buy this kind of thing here.
Are these the only ones that can be used as substitutes? Graphite, tetrafluoride, asbestos.
This post was last edited by xh8618 on 2017-4-4 09:29. What is the pressure and temperature? Generally, packing material is sufficient; the cut ends should be stacked one on top of the other, with the cut ends of the upper and lower layers offset by 180°. For low pressure and high temperature conditions, graphite fiber packing can be used, while for high pressure conditions, graphite packing with steel wires is required. In theory, liquefied gas tetrafluoro fibers are better. The packing material doesn’t contain asbestos; it’s probably a mistake upstairs
There is also the issue of frictional resistance with graphite and PTFE. An actuator using PTFE packing can open the valve properly, but this may not be the case when graphite is used. Generally, when selecting an actuator, we choose graphite packing that is one to two grades higher in quality than PTFE packing.
You can directly add PTFE material, which is available for purchase; if that’s not an option, then use raw tape instead.