English to Russian Tech/Engineering Engineering (general) filters, dedusters

Only replace the dust collecting container after filter shutdown.
Close the shut-off butterfly valve (if installed).
The plastic bag welding device may only be used in a non-ex zone.
(Otherwise ****tie off**** the plastic bag twice and cut through between the two ties).

Речь идет о пластиковых мешках фильтров, куда после фильтрации попадает пыль.
Спасибо!