Measure Mains for Vents.

ST140

Hi Everyone. I just ordered two Gorton No. 2's for my mains because from what I've read, they will vent the mains the fastest... But then I started getting curious about my mains, and how much venting they actually need. I've seen requests for people to measure their mains, and give the pipe diameter, and then they end up recommending main vents. OK, makes sense. Now here's my dumb question. I have 1 pipe parallel flow steam. 2 mains coming off the boiler, one to the front of the house, one to the back. When you say, "measure the mains" does that mean the entire main, going away from the boiler, and coming back? I guess I get confused as to what is considered the main, and what is considered the return. I think I understand that it's a dry return, but is that still considered part of the main? Or do I stop the measurement where it turns 180 degrees back to the boiler? Sorry if this doesn't make sense... but Thanks!

ST140

Ignore this post.

If there's a way to delete this post, please do so. I accidentally submitted it twice somehow. Thanks!