Galvanized to a fitting made for copper

Older (1929) home - water lines 1/2" galvanized.
Just bought a tub/shower fixture (Danze).
Connections out to the shower and tub are threaded fine for galvanized.
Connections IN though are a nut screwing down over outside threads for connecting 1/2" copper.

Danze's customer support was no help in recommending a good solution for making this connection - nor were the big box people -- no surprise --
SO -- I took the faucet to a 'real' plumbing supply store that caters to the trade --
A couple of his people studied long and hard - apparently this is a strange fitting on this faucet.
Finally the owner chimed in and suggested brass compression fittings - on both the galvanized and the faucet -- with copper line run between.
Sorry - no pictures - hope this description makes sense --

Bigger question is -- does this solution make sense.
It does to me -- but I am WAY out of my field here.

This shop has been in business for YEARS and the owner seems well respected so I tend to trust him - but would welcome other opinions.

Thanks

http://www.buydanze.com/pdfs/spec_sheet/D504054BN.pdf

The drawing for the Danze (at the site) appears to use a 1/2 -14NPSM which is a straight thread, not tapered, for a mechanical fitting. You can get fittings which allow you to swivel the pipe.

However, there is a note on the drawing that says the ports of pressure balanced valves are combination 1/2" copper sweat and 1/2 NPT.

There should be a sheet in the package that says which you have.

If you have the NPSM then you need special fittings. Otherwise, you can use the threads or the copper sweat. If you sweat, you should pull the cartridge out first so you don't damage it.

The sheet indicates the fittings are 1/2"-14NPT
The supply store owner mentioned the possibility of just sweating the copper inside - and mentioned disassembling the unit to avoid heat damage.

One reason he suggested the brass compression fittings was that I had never sweated pipe before - and likely never would again - and he was trying to save me both the expense of buying torch etc for one job - and the time of learning a whole new skill.

The same logic for using the compression fitting comin off the galvanized.

I had heard that going galvanized to copper was problematic andtook a special dielectric union. He indicated that this would not be a problem since I was using the brass fitting between the copper and galvanized.
And for that matter - in his opinion the actual value of dielectric was open to debate.

I guess my concern is whether I am asking for any problems he has overlooked by going this route?

And YES -- I am wishing I had taken the time before starting this project to learn to sweat - and had gone with copper all the rerouted pipe.
But -- not badly enough to go back and do it all over.

Disappointing water pressure

OK - got the fittings and the faucet connected -
Water pressure very disappointing.
Is this normal with pressure balanced faucets?
It wasn't GREAT before - but I blamed that on corrosion in the old pipe.
I am running brand new 1/2" pipe beginning with the risers coming out of the ground.
Was HOPING for an improvement in pressure.

hope

You didn't do anything to the major portion of the piping, and yet you still hoped for better pressure? That takes real faith and a belief in miracles.

Sorry if my question sounded foolish -
No - no trust in miracles here - I'm old - not senile -
But I do plead considerable ignorance in this field --
That's why I appreciate places like this.

My hope for at least some improvement in water pressure was based on the observation that water preasure elsewhere in the house and in the outside faucets seemed greater than in the tub/shower. My reasoning from that observation was that there might be corrosion in the fixture itself or in the lines running to and from it. So yes - having replaced the fixture and all pipe back as far as the underground lines ---
I reasoned/hope I might see some improvement --
Faulty reasoning perhaps -- but - no -- no reliance on miracles of any kind.

When you disturb fittings, and sometimes in the new pipe itself, there is some crud broken loose. Before you give up, take out any screens that may be in the inlet or outlet of the fixture and check them for an accumulation. One of the "standard" steps in installation is to flush the lines. Many people don't do that, and it can plug things up. If you are lucky, it may help, but it probably won't.

Yep - all too familiar with that -
There is so much crud inside these old lines that almost any time I shut the water off - I have to clean the screen in the kithchen faucet and flush the toilet fill line.

I would LOVE to replace ALL the old lines back to the street -- or at least back to the first main junction ---
BUT - this house was built before code required crawl space.
To get to the underground lines and dig them up for replacement - would mean tearing holes in floors throughout the house. SO - I'm kinda stuck with what I got.

Think out of the box

Just because the OLD pipes are underground doesn't mean the NEW ones have to be. I just replaced my old cruddy underground pipes with new clean in-the-attic pipes. Getting from the attic manifolds to the fixtures required some creative routing, but so far, so good.