Putting brass fittings into stainless steel fixture?

[hdtvkeith]

I think I know the answer to this and I am sure I will probably get different answers as my friend Google gave me mixed results. I have water filters that have 1 inch stainless steel female connections. I used 1 inch male to 3/4 Propex brass fittings with teflon thread tape. Not sure why I started questioning my work, but stumbled across various opinions that the brass and 304 Stainless will cause galvanic corrosion over time. Of course all is well right now, but I don't want to deal with issues in a few years. I found some 1 inch to 3/4 potable schedule 40 bushings that I can then thread either poly or brass fitting into to avoid the metal to metal contact. Thoughts?

 

[Geofd]

Couldn't you use aplastic pex adapter right out of the filters,as long as you don't over tighten the plastic I think you would be okput a union in there also so if you have to work on it you just loosen the union rather than cutting and repiping

 

[Twowaxhack]

I think I know the answer to this and I am sure I will probably get different answers as my friend Google gave me mixed results. I have water filters that have 1 inch stainless steel female connections. I used 1 inch male to Propex brass fittings with teflon thread tape. Not sure why I started questioning my work, but stumbled across various opinions that the brass and 304 Stainless will cause galvanic corrosion over time. Of course all is well right now, but I don't want to deal with issues in a few years. I found some 1 inch to 3/4 potable schedule 40 bushings that I can then thread either poly or brass fitting into to avoid the metal to metal contact. Thoughts?

View attachment 35878

It’s fine, you won’t have any problems at all.

 

[hdtvkeith]

Couldn't you use aplastic pex adapter right out of the filters,as long as you don't over tighten the plastic I think you would be okput a union in there also so if you have to work on it you just loosen the union rather than cutting and repiping

There is no plastic pex that reduces from 1inch to 3/4 inch, only brass, which is what I used. There is a Potable PVC reducers or a stianless reducer that I would use then do a pex 3/4 plastic.

 

[Twowaxhack]

Does your home have a thermal expansion tank ?

 

[hdtvkeith]

Yes, I have it set to 63lbs. Put new L type Copper around water heater area and installed new expansion tank with the new piping. 50 gallon water heater (1 year old) and a 4.5 gallon expansion tank as I am a bit overkill on many things. I fabricated new copper for the 2 bath/shower fixtures and left all the non-pressure side copper on those fixtures.

 

[Twowaxhack]

That tank probably has a stainless male thread connection. Take it apart and see what it’s doing connected to that copper.

 

[hdtvkeith]

Good point, my guess is nothing yet only been in place 2 months. But they is a good point as when I took the old tank down from its copper connection that was installed probably 10-12 years ago it looked fine, it spun right off no issues.

 

[Twowaxhack]

I find that sometimes the corrosion is between the stainless and the steel tank itself. So the stainless inlet eats the tank……

 

[wpns]

Depends on the conductivity of your water, but with most water supplies you should be fine.

 

[hdtvkeith]

Thanks, municipal water that supposedly passes all the required tests form the FDA.

 

[Twowaxhack]

Thanks, municipal water that supposedly passes all the required tests form the FDA.

I’ve used stainless and brass for almost every application in plumbing you can think of. Sewage, potable, natural gas, propane. Never have found any problems. It will have problems on reverse osmosis systems so don’t use it on reverse osmosis water. It’s highly acidic.

I for sure wouldn’t use pvc inside my house for potable water.

 

[hdtvkeith]

Yeah I am good with the brass based on what everyone here said. It is in the garage so I see it everyday should something go sideways over the years and I have a bypass set up so can take the filters out of the path easily.

 

[Twowaxhack]

Yeah I am good with the brass based on what everyone here said. It is in the garage so I see it everyday should something go sideways over the years and I have a bypass set up so can take the filters out of the path easily.

I predict one of your three ball valves will fail within 12 yrs. Either it won’t cut off or it’ll leak from the stem.

Filter leaks or some type are common also. I’ve been to a lot of houses that have flooded from a filter cropping the bed.

I’m impressed with your choice of filter heads. You seem like a competent DIYr. I like your attention to detail.

Maybe you won’t have any trouble but I feel like that’s more of a concern than the dissimilar metals. It’s easy to become a pessimist doing repair work everyday.

 

[hdtvkeith]

Wow that is interesting prediction and I guess reassuring on the brass fittings and not so much the valves.

 

[Twowaxhack]

Wow that is interesting prediction and I guess reassuring on the brass fittings and not so much the valves.

Don’t worry about it, I’m wrong all the time

I find that some things repeat……I find bad valves a lot.

 

[Bird Doo Head]

In my work, bimetallic electrolytic action is a daily consideration.

Brass versus steel is never a problem because of the zinc in the brass. Typically found in threaded fittings, bolts, flanges & similar is about 33% zinc.

You're triple covered:
The 304 stainless also prevents galvanic corrosion because of the high chromium content.
The fact that the fittings are grounded through the piping or water's minerals makes your project very well protected against corrosion & galling.

Even copper and aluminum can be in contact when zinc is present. That's the active ingredient in the anti-ox paste that's used for such connections in the electrical industry. Aluminum to steel is another extreme example where a zinc paste will save the parts.

 

[Twowaxhack]

The fact that the fittings are grounded through the piping or water's minerals makes your project very well protected against corrosion & galling.

Could you explain further ? Just the part of your post I’ve quoted.

 

[hdtvkeith]

As a side note I had emailed Uponor last week and they replied today saying their brass fittings are fully compatible with stainless steel. So I got all worried for nothing.

 

[hdtvkeith]

The fact that the fittings are grounded through the piping or water's minerals makes your project very well protected against corrosion & galling.

There is no grounds thought the piping it is all Pex. The main enters the house and right after the PRV I transition to Pex, then pex is everywhere except shower/tub valve areas. And to stay code compliant knowing I would be removing the copper I put in 2 new 5/8 listed ground rods a few months back. since the copper pipe being removed negates 1 of the 2 required ground paths. I find it amazing that with all the plumbers I talked to to get quotes last year, none of them mention that removing the copper pipe negates a ground path.