It has something to do with valves and the like, to let steam escape from boilers or somesuch. From HVAC: (http://go2atp.com/ATP/showdetl.cfm?&DID=7&User_ID=229032&st=3798&st2=49517319&st3=-88467651&Product_ID=86&CATID=5)
"Valves located on the water column that are used to determine the boiler water level if the gauge glass is not functional."
PS -- I designed the cover on that book. Go look at again. Ooooh. Aaaah.
no subject
Date: 2004-01-26 10:48 pm (UTC)no subject
Date: 2004-01-26 11:04 pm (UTC)no subject
Date: 2004-01-26 11:39 pm (UTC)"Valves located on the water column that are used to determine the boiler water level if the gauge glass is not functional."
PS -- I designed the cover on that book. Go look at again. Ooooh. Aaaah.