hydraulic separator piping

dobro23

just wondering "in your opinion" what the correct placement of the expansion tank, water feeder, and boiler side circulator is when using a hydraulic separator. I have searched online and have found all configurations. my experience in the field has shown that these components are almost always on the return side of the boiler circuit between the separator and the boiler return with the expansion tank and feeder on the suction side of the boiler circulator. i assume this is safe but is it best? with conventional piping ie no separator, i generally put my zone circulator(s) on the supply of the boiler just after the expansion tank/feeder. wondering why the hydraulic separator seems to always be reversed in essence by pulling the water through it and pushing it back into the boiler. hope this makes sense. what do you guys think?

Tinman

I like to try it different ways and honestly it's worked well each way I've tried it.

hot_rod

Really not much difference. Wherever you connect the entire sep becomes the PONPC.

On the multi boiler system with the large floor mount tanks, the expansion is connected at the end of the large headers off the sep.

Avoid putting the tank directly below the bottom port of a separator as dirt and crud may settle onto the diaphragm in the expansion tank and cause wear.

Here are some examples from Idronics 15.

Ironman

Or, you can do it like this:

Gordy

Well @Ironman that shoots the hell out of the debate of which is considered primary, and secondary side with the PONC as the focus....I like it.

hot_rod

Nice, creative. I like the exp tank mounted horizontal with that sturdy bracket. Hydro-Claw?

You have the backflow correct also. They can only be vertical if flow is down.

vi

Ironman said:

Or, you can do it like this:

Ironman

Yes, HydroClaw.
I've heard some folks say that you're not supposed to mount the expansion tank that way, but I've never had a problem with it and can't find any documentation to say otherwise. Mark Eatherton says it's okay. That's good enough for me.

If you think about it, a floor tank has the connection at the bottom, not the top.

hot_rod

Ironman said:

Yes, HydroClaw.
I've heard some folks say that you're not supposed to mount the expansion tank that way, but I've never had a problem with it and can't find any documentation to say otherwise. Mark Eatherton says it's okay. That's good enough for me.

If you think about it, a floor tank has the connection at the bottom, not the top.

Page B3-5 in the Amtrol book indicates approved horizontal mount, if ever you get called out on it, or an inspector challenges you.

Tinman

@Ironman - I do it all the time.

Ironman

hot rod said:

Ironman said:

Yes, HydroClaw.
I've heard some folks say that you're not supposed to mount the expansion tank that way, but I've never had a problem with it and can't find any documentation to say otherwise. Mark Eatherton says it's okay. That's good enough for me.

If you think about it, a floor tank has the connection at the bottom, not the top.

Page B3-5 in the Amtrol book indicates approved horizontal mount, if ever you get called out on it, or an inspector challenges you.

Thanks, Stephen!