Thanks to all for answering my queries about plant air/ instru air.
I have one more query regarding IA air systems. I wanted to kno wthe reason why galvanized iron is prefered for IA and also why are the valves normally Scrwd and not SW?
There is no physical or safety related reason, though I'll bet someone will make this claim, for using galvenized in air service.
Here are some reasons why galvenized is used.: Beacuse the pressure is low and the lines are not covered under B31.3, thinner pipe is used. External corrosion is a problem, so it it galvenized to lower external corrosion. The gavanized line is easily identified and helps keep people from getting the wrong line.
Soket weld valves are a pain and should be avoided IMHO. But welding on galvanized pipe is dangerous, the fumes from the zinc coating are toxic to the welders. Futhermore, you damage the zinc coating and then the socket weld has to be re coated in the field, not easy to do unless it is "cold" applied.
thanks! this helps:-) But can u kindly expand on this statement:"and the lines are not covered under B31.3, thinner pipe is used". you mean, galvanized pipe thickness i snot governed by the B31.3 code/formula? if so why? how then is the thickness due to internal pressure calculated?
Regarding Instrument air MOC
Re: Regarding Instrument air MOC
