Where to add air vents

davidheating

Looking for help with venting the air out of the mains. Having the usual issues of water hammer and radiator air vents spewing water.

House is a 4 story with a basement.

Photo 1 shows the short main with no air vents. Where should the air vent be added on this main? Can I add it at the plug in
point C or is that too far from the last takeoff? If not
would it be better drill and tap the tee (B) or the elbow (A) for a new air vent?
What size gorton should I add here - I don't think I have the clearance for a no 2.

Photo 2 is the long main with a Gorton D as a vent. I'm assuming this is undersized should I add multiple no 1s here?

Thank you All!

ethicalpaul

point C is the easiest but that last radiator will be a little slower than the others. I say it’s worth a try.

Your D vent is the exact same as a Gorton #1. That might be good enough. If the main is at all cooled from the last call for heat, the vent is not taxed because the steam is slowed by heating the pipe. Yes even insulated pipe

Long Beach Ed

Point C would be fine for the vent, but don't think that plug is coming out with some toy wrench. As Ethical alludes, your last radiator will be venting a bit extra pipe, so you may want a larger vent on it if the system can handle it.

Do take note though that water hammering and water issuing from radiators indicates problems that won't be solved by piping a couple of main vents.