Replacing old style 2 handle tub valve body

[leemort]

Well, now that I've finally fixed a bathtub spout/handle leak, wife is wanting to convert the tub into a tub/shower.

I have galvanized steel pipes with a valve body that looks like this Pfister valve body which I am considering using as a replacement. The only difference I can see in the Pfister and the one in my wall is that mine does not have copper adapters and only has the one outlet for the tub spout.

I am wondering if the new valve body would have to be sweated onto an adapter before the existing galvanized steel, or would it be sufficient to just thread it on? Existing valve appears just threaded steel to steel. Pfister specs state the valve has union inlets/outs.

I can add a photo of the one in my wall if needed, but it looks exactly like this one.

According to pfister, the bolt plugging the top outlet can be removed so it is both tub & shower.

 

[TomFOhio]

If everything lines back up with the new unions and the threads on the old galvanized look good then you
shouldn't have any problems. Just make sure that when you take the old unions off that you back the pipe
up with a wrench and the same when you put the new unions on. I personally would not use the old unions. And yes you take the plug out of the top and that goes to the shower and the bottom goes to the spout.