Grundfos529912 GU 125 Bronze Union Flange - 3/4" NPT

My hot water recirculating system recently had a near catastrophe with severe copper corrosion that necessitated replacement of the pipes leading to and from the Grundfos recirculating pump. Since the system had originally been assembled with soldered joints, I had to replace the union flanges on both sides of the pump. As you would expect from Grundfos, these components are very well made and heavy duty. I opted to go with NPT joints this time to make it easier if I ever need to replace the surrounding copper pipes again. The project went well, and these flanges fit the original pump perfectly. I’m very happy with the quality of these parts.

Perfect fit and great quality

I replaced my old recirculation pump with a newer model. The new model uses these union joints so that if I ever need to remove and replace the pump it will be much easier. Seemed a bit pricy though.

This kit worked PERFECTLY to connect up the pump AND make it super easy to remove/replace/evacuate air via the shut-off valves. The machined surfaces are perfectly flat and the flat rubber gaskets work well to seal up the connections with very little torque. Use these kits without hesitation. And do pay attention to the type of connection you are purchasing. This one is the 3/4" NPT thread as it is clearly stated.

I THOUGHT THEY WERE SOLDER ONLY TO GET THEM AND FIND OUT THERE FOR IPS WELL THAT SUX I SHOULD HAVE RETURNED THEM BUT HEY