French to English Tech/Engineering Petroleum Eng/Sci major shutdown for maintenace work

This large document is all about procedures (HSE and other) for handling the very complex process of shutting down a petro-chemical plant (the document is a general one, so might apply to all sorts of different types of plant).

The word 'capacités' recurs frequenrtly in this rather odd usage; here is one example, I'll try and post a few others as I come accross them:

"isolement du point d’intervention par les platines déjà posées dans le cadre des isolements pour les TRAVAUX EN CAPACITÉS, en s’assurant que la platine commune à plusieurs travaux est identifiée sur le terrain et est gérée"

It is clear empirically from the context that this refers to some kind of container (in a conceptual sense) — not to 'capacity' in the classic sense of 'how much it holds', but rather in the sense of 'something that contains something' — and please note this is quite specifically differentiated from working in 'confined spaces'; clearly, some of these 'capacités' are mighty big! They are indeed 'enclosed spaces', but I am reluctant to employ that term, which seems to be slightly skewed from the meaning here —i.e., it refers to 'the space that is enclosed', rather than 'the object that encloses space'

I am also reluctant to use 'container', though that is the only suitably generic term that springs to mind; would anyone have a better idea of the specific term that is used in the p/c industry, please?