Potential Flange Switch

itowngirl87 · December 28

Hi everyone,

We are looking to potentially switch out the flange in the dedicated space between the metal sections as shown. Please note that the flanges are slightly different on the base. It looks like they should fit but hoping to hear group input on any concerns given the tight space involved.

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mattmia2 · December 28

the flanges fit the same. you'll need new gaskets and bolts to install the new circulator

itowngirl87 · December 28

Thank you. We have new gaskets. Do you think the old bolts won't fit?

hot_rod · December 28

are you trying to address the old leaky gaskets? Or swap pump brands?

Remove the bolts, slide the pump out, clean the surfaces and replace the new gaskets or o-rings.

You may be able to reuse at least those upper bolts, perhaps the lower ones if you spray them with WD40

That pump typically seals with a square o-ring , in a groove in the pump body. but with some flanges you need to use a flat gasket to seal to the flange. When you remove the pump you will see what was used.

mattmia2 · December 28

you can measure to see if they are long enough but since they are all crusty i'd replace them so getting them apart in another 30 years isn't a problem for the next person.

hmm…i thought i hit send

hot_rod · December 28

https://forum.heatinghelp.com/discussion/comment/1879505#Comment_1879505

I believe those are isolation flanges, the metal flange slips over an edge on the ball valve, A plastic snap ring locks it together. So it is a flange specific to that valve assembly, I doubt you would find that flange.

That is also the reason it requires the flat gasket, which comes in the box with the valve.

Various brands of these one piece flange/ valves like this are available.

mattmia2 · December 28

I think they were concerned that the casting on the new circulator is different than on the old circulator which isn't a concern as long as the bolts are long enough.

hot_rod · December 28

https://forum.heatinghelp.com/discussion/comment/1879549#Comment_1879549

Yep, the question is unanswered.

Is this a pump swap, or just a gasket/ leak repair?

Flange replacement may not be an option.

Grundfos and Wilos run about 1/8" wider flange to flange than Taco, but the piping usually allows enough movement to accommodate that 1/8" difference.

Replacement bolts are 7/16 X 2" length. Chrome or zinc plated are best. Available at most any hardware of home "box" store.

I'm pretty sure you would need flat gaskets with those flanges.

I would not attempt any repair or removal without new gaskets on hand.