*HAC stands for hazardous area classification.
Question: shall we take into consideration in case of HAC, if there is any ignition source present or not? do we Ex classify an area where is Ex hazardous environment, but no ignition source at all?
Answer is definitely YES. pls take a look at all the pentagon (dust) and triangle (gas) above. If all exist, there is an explosion and not a hazardous environment only.
Keep up good work!
The issue of hand-operated valves: Given that these will move slowly, with
The understanding and continuous support of management is essential, and shall be present and available from the 1st day of Ex issues related to site compliance.
So it shall start with design, and follow up.
Ex compliance shall be verified to the design stage. the design stage of product, site, and operation.
#exprofessional
As NASA relies more on lithium-ion batteries, the space agency has a
Absolutely inerted mixture is one which does not form a flammable atmosphere
arpadveress 
