Uponor A2700A SS Manifold body end cap question

tropostudio

Has anyone here here removed and re-installed the factory end plugs on an Uponor A2700 series stainless steel manifold?

I am looking to install a differential pressure bypass valve in my system, and this is the best place to install it if at all possible. Trust me on that.

This is a 1" manifold body, with 1" ball valves. Measuring best I can, I'm guessing the plugs are an R25/1"BSPP thread with a flat washer or O-ring. The R32 fitting on the other end must be installed the same way. There is no information available from Uponor and I can't get a straight answer using a detailed AI prompt. I can't believe it's a press fit - if it was, it wouldn't need a nutted end.

hot_rod

on the Caleffi manifold the end caps have a gasket and are also assembled with Loctite. Basically a super glue type product

With two zone actuators you shouldn’t need a bypass valve. We suggest 4 or more zone valves, consider a pressure activated bypass. Maybe you are adding more actuators?

A better option would be a delta P circulator it will adjust its flow rate based on which loops are open. Also save 50-80% electric consumption

tropostudio

The system has 3 manifolds, each with 5 loops of either 3/8 or 1/2 PEX. Homerun system with panel radiators. 1 Grundfos Alpha fir circulation running in constant pressure mode (mid setting). TRVs on emitters except for the two thermal actuators you are running on open panels. No PS pump. Westinghouse/HTP Universal fire tube boiler (no longer made). Set for 25F Delta T.

Concern is this: minimum flow rate spec for boiler is 1gpm. I've heard the flow meter for the Alpha is sketchy at best, but there's a lot of time where it's reading 0 gpm. My flow calculations show a really low flow system, and I believe it can be running under 1 gpm a lot of the time. I hear tea-kettling quite often. I'm not worried about dead heading the Alpha. But I figure a few more watts on the pump won't matter if I don't have to buy and re-plumb for a new boiler several years too soon!

BTW, was planning on installing a Caleffi diff bypass valve 😊

hot_rod

Try the Alpha in fixed speed 3.

The Alpha is a delta P circulator. You would have to lock it in fixed speed if you install a pressure bypass valve. So one or the other.

Can you attach a pic of the boiler piping. The boiler should be piped primary secondary or with a separator. That way it always gets the correct flow, if only one zone is open, for example.

Kettling sound could indicate inadequate flow through the boiler