Air Separator

oldpipefitter

Ok, I been in this stuff for a good many years but i don't pretend to know everything. In fact some days its painfully apparent that I'm not the brightest stick in the woods.  I got this little hot water system to pipe up, no biggie. Now I got a Watts AS-M1,  2 1/2" and a big old bladder expansion tank. The tank is tapped 1 1/4" but the bottom of the watts is only 1/2". I have a drawing that clearly shows the tank piped into the bottom of the air separator, with of course, water make up coming into that line. It also shows that the line from the tank is 1 1/4".  Now at first I thought I was sent the wrong separator, but checking, this is what was called for. Now , realize, the man who drives the train (engineer), not only designs and drew this but he also supplied the parts........ so here's question 1....... is it normal/ OK/ accepted   to tie an 1 1/4" tank into a 1/2" tapping? ......Question 2...... If not, what is? ..... Question 3......There is a 1" tapping on the top of the separator, along with the 1/8" one. Can I assume this is for when you use a good old fashion horizontal tank above the boiler?  Just for the record, the man who drives the train will also be the guy who approves the job so the guy that signs my check gets his check signed....so....its going in exactly as drawn. I just need to know, you know....

Mark Eatherton

It does not matter...

The connection between the scoop and tank can be 1/2", all the way to the tank if you want. Pipe size is normally based on velocity. The exchange of water between the system and the expansion tank are so subtle so as not to even notice. If you want to keep the engine ear happy, then run 1-1/4" from the tank to the 1/2" tapping on the scoop, but betwixt you -n- me, it doesn't really matter...



ME

JStar

You can also...

...pipe a tee in near the separator and run your tank the full line size. That's what I do for every tank over 1/2". The tank does not have to be piped into the separator...it's just convenient, when possible.