Dialectic Union

I suspect this is a dialectic union but how can I be sure? Is there any kind of marking to indicate?

Sorry having trouble getting an image to upload.

Does it look like this?

Plumbing - water heater dielectric union.JPG

I still cannot get an image to upload even though I switched browsers. The piece I saw was all brass attached to the galvanized nipple at the top of the water heater. It did not look like the normal soldered fitting.

If it doesn’t look like or closely resemble the picture I posted, then it probably isn’t. The key “ingredient” is that black piece of plastic or rubber (bushing/washer) that separates the two different metals.

The best dielectric union is simply a brass connector.

I finally got the image to load. See my original post.

There is no union at all in that photo, just a flexible supply line connected to the water inlet’s nipple.


The connector in the photo is not dielectric.

Thanks for the feedback. That fitting did not look like any that I have seen or any of the illustrations.

That is a dielectric fitting, technically, and there’s nothing “wrong” with it and/or absolutely no need for a “typical” dielectric union like I posted (unless you have a crazy city inspector that requires the “typical” one like I posted.)

I disagree, there is no sleeve visible, and as TREC inspector he had better document it. TREC has a penalty matrix for such lapses. I would document it as “could not confirm…” unless I saw a label or sleeve.

I wouldn’t argue that the presence or absence of a dielectric makes any real difference considering that the water within the pipe itself is an electrolyte.

I could see where you say no visible sleeve or label, but it isn’t visible, it’s inside.

Those nipples are plastic lined and often shipped with the water heater. And the word is dielectric.