Glen boy

Hi, new member here, sorry if this has been asked before, I did do a search but didn't find an answer. My question is around the operation of Cordon gas tanks. I am aware of many photographs of Cordons left at stations for the refilling of gas equipment in coaches, horse boxes and stations buildings, but how were they operated? Did they have associated pipe work for the refilling, and was it a question of just connecting up and waiting for the tanks to fill ? Would there have been an exclusion zone around the filling operation where by an engine in steam could not enter? Would there be permanent ridged pipe work installed to connect them to the station infrastructure? When transported did the normal flammable material regulations apply ,i.e. not next to the engine and barrier wagons in between? Indeed could they be marshalled with coaching stock at all? Again sorry if its already been covered elsewhere. BR Glen