Caleffi manifold configuration

152NP

@hot_rod I know you are a Caleffi guy, so probably the best person to ask this question. I have a Caleffi inverted manifold. In my particular situation, it would be better to locate the supply to the upper position, and the return to the lower. I am wondering what the purpose of the spacer in this photo is.

If I swap the locations of the supply and return, I will also have to move the spacer so I can fit the differential bypass between the two. I do understand that the differential bypass will have to then be put in the opposite direction.

What's up with that spacer, and is there any significance to it being on the return manifold?

I am very impressed with the quality of this thing!

newtonkid88

Ugh… I remember either reading or watching on youtube what that spacer is for. But I cant remember the reason

Anyway, you might find that the lower-right port’s pex wont work in that bracket configuration. The upper bracket gets in the way. 

I had to flip the brackets. The lower-right pex pipe still rubs on the bracket but at least it can go over it. 

I wish they sent the manifold with the opposite offset angle. 

152NP

@newtonkid88 I am pleased to know that I am not the only who wonders about these things. Thanks for the warning about the brackets and pex pipe clearance. It would suck to install everything and then realize there is a problem.

152NP

After looking at some Caleffi items online, I am thinking it looks like a service check valve for the air vent, but why only on the return?

newtonkid88

152NP said:

@newtonkid88 I am pleased to know that I am not the only who wonders about these things. Thanks for the warning about the brackets and pex pipe clearance. It would suck to install everything and then realize there is a problem.

The only way I have found so the pex doesnt rub on anything is to flip both manifolds around. Then you’ll have to loosen and reposition the main valves at the union connection and flip the drain valve handle.

hot_rod

It is just a brass spacer that in needed when the manifolds are in the standard pattern.

The pressure bypass is only needed if you use multiple actuators. Better yet get an ECM delta P circ and you don't need the bypass.

152NP

@hot_rod I do have a Grundfoss Alpha 2, so I guess I can return the bypass. You just saved me a few dollars!

hot_rod

yep, and save the hassle of fitting it onto the manifold.

152NP

@newtonkid88 I was playing around with the manifold/bracket configuration and now see what the spacer would be for. Without it, in the normal orientation, you would not be able to get the fastening clip in place.

newtonkid88

152NP said:

@newtonkid88 I was playing around with the manifold/bracket configuration and now see what the spacer would be for. Without it, in the normal orientation, you would not be able to get the fastening clip in place. 

That was not an issue for me. Move that upper manifold to the right a little bit and it fits. My issue is that lower right manifold pipe would hit that bracket.

I have mine set up as shown in your picture. I wanted the flow meters on the top, protected by the pipe. I am clumsy and I know I would smack and break those vials while I was moving something in the basement.