Constant-temperature steam trap
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I would be extremely grateful if an expert could explain the working principle of thermostatic steam traps and the precautions regarding piping. Thank you so much!
The last edit to this post was made by ylb913 on 2018-6-16 at 20:01. I’m aware of two types of thermostatic desiccants: the bimetallic type, also known as memory metal, which takes on different shapes at various temperatures; and another type that uses some kind of expansion element. The biggest advantage of a constant-temperature drain trap is its stable drainage temperature, with the drainage temperature of the bimetallic element being adjustable. The biggest drawback of a constant-temperature trap is that it can backflow; it can still be used even if installed in the wrong direction. The flow direction arrow on the trap is there because there is a filter screen at the inlet. Furthermore, bimetallic steam traps require that the pipeline ahead of them, over a length of more than one meter, not be insulated, because of their ability to flow in reverse direction; if the trap becomes hot, it does not necessarily mean that it is functioning properly as a steam trap.
If it’s over 1 meter long but can’t retain heat, why is that?
It seems to be used to check the hydrophobicity; by reaching a little further forward, the hydrophobicity can be determined based on the temperature of the pipeline. We have never implemented this; at first we were unaware of it, and it seems that the larger design institutes involved in the general contracting projects also weren’t aware of it. In any case, the design institutes did not fulfill this requirement.
That’s right; for dual-metal sheet steam traps, there must be a cooling section at the front end, and they are more suitable for use in pipe racks for steam drainage.