What do tso and sco mean, which are indicated next to the valve?
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Dear everyone: While looking at the shell flow diagram, I noticed that TSO and SCO were indicated next to the valves. After checking, TSO is an abbreviation for “tight shut-up”, which means to close tightly. In my understanding, this implies closing the valve completely. For on-off valves, it means closing it all the way; whether it’s truly closed is determined by a GCO (limit switch). What are your thoughts on this? As for SCO, it stands for “air and spring closed” – how should this be translated?
\"Air Open / Spring Close\" means the valve opens when air is applied; \"Air and Spring Closed\" could either mean the valve closes when air is applied or stays open, so please advise if this is incorrect
I also want to know what SCO means