I second TD2K - thats what i have seen the most places.
Pennpoint: Car sealed means that the hvalve handled has been "locked" using a "seal". Today this would most commenly be a plastic strip but also old-fashioned wire and actual sealing wax can be used.
There was a thread on the origins for this expressions in one of the fora here, I think it was the "Engineering Language/Grammar Skill" Forum. I can't seem to find it and due to that forgot who exactly pointed this out, but apparently it comes from former times, when equipment has been delivered by railroad and the railroad cars have been sealed to ensure noone has tampered with this equipment. Hence, the expression "car-sealed" to indicate the valve MAY be operated, but not so without being noticed.
Who else but Montemayor could have explained that? I could have guessed. So, belatedly but not too late I hope, thanks Montemayor for another scrap of information that stuck to me.
CSO/CSC are different with LO/LC. The former uses wire and lead seal to limit operations to valve, people can break the seal in emergency situation. The latter uses chain and lock --- can't operate the valve until get the key.
