Breaking of a venting screw is in most cases due to misuse or lack of cleaning/maintenance of the part.. Using HF will have no detrimental effect.
The suggestion is to regularly inspect all venting screws, and clean when necessary. Also, it is important to only close the venting screws finger-tight (don't use any tools). Additionally at the end of each experiment, the venting screws should only be opened one full turn (360°), no more.
Additional instructions for proper maintenance of vessels, caps, and other consumable parts can be found in this document: http://download.anton-paar.com/filetransfer/D56A564D25AF48EAC1257CAE004189A0
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