Circulators with IFC internal flow checks, some discovery.

hot_rod

I built this clear pump display to try and observe the small spring checks in action. The IFC fit right into the discharge of the circulators. They have a low "pop" pressure, around 1/2" psi.

First off you want to have some sort of strainer, filter, dirt separator in the piping. It doesn't take much more than a grain of sand to hold them open. See the particles on the paper towel.

On my first run I had some of the clear plastic machinings in the piping and it held the check completely open immediately.

Next the pump and circuit needs to be 100% air free. On first start the air entrained in the fluid would cause the check to bounce, flutter, chatter, pick a word. In this short demo loop it took less than a minute for the air separator to clean the fluid of all air. The check operated smoothly from then on.

Troubleshooters tell me they have replaced these damaged checks after 3-5 years of service. I suspect the checks chatter themselves to an early death.

The check is in a turbulent condition this close to the impeller. Most any check manufacturer asks for several pipe diameters distance between a pump discharge and the check.

All in all, properly protected and commissioned I do see the value in these spring type, conical seal type of checks in circulators.

GGross

Well you get to have all the fun huh?

mattmia2

If someone was getting ghost flow, the ifc failing would be one of the last things I would think of but apparently it should be the first.

GroundUp

Well darn it, now I want a clear poly volute

jumper

Should have known that it was too good to be true.

back to zone valves?

hot_rod

https://forum.heatinghelp.com/discussion/comment/1846033#Comment_1846033

The weighted flo-checks are pretty durable and effective. A large enough piece of crud could hold them open a bit also.

I like the spring type hydronic checks, they are a bubble-free seal. The key is keeping the fluid clean. But this applies to balance valves, thermostatic valves, really any device in the fluid stream.

tim smith

one of the main failure points we found with IFCs. The plastic pin that slides back and forth through pin hole would vibrate enough over few years and cause a groove in pin which would hang up and not allow to close.

Alan (California Radiant) Forbes

It doesn't happen very often. And it takes awhile to figure out the culprit.