Water heater install (CA)

[Shopco]

14 years ago I installed the water heater using copper pipe (no flex line) to dielectric unions installed on the water heater.

When I attempted to replace the water heater the unions were welded together. They came away from the heater ok but would not disassemble as designed; I had to cut the copper pipe. Even when taking the unions to the bench vice there was no separating them. They were heavily corroded.

I am endeavoring to prevent a repeat of this situation and want comments on my plan, which is;

[copper pipe] to [dielectric union] to [12" neoprene hose with 316 stainless steel fittings] to [water heater].

What I want to know is if this will eliminate the corrosion on the dielectric unions.

 

[Reach4]

You might post a photo.

California requires flex lines, so that can affect what you do.

 

[Sponsor]

 

[Jadziedzic]

Is the neoprene hose rated for high-temperature operation? What about potential for bursting? I would expect over time the hose would start to degrade, flaking pieces of the hose into the water supply. Why not use the flex copper lines?

 

[Shopco]

Neoprene hose used is designated hot pressure washers. 565 psi @ 72 - 210 max temp. House pressure is 80 psi. Expansion tank installed.

Hose = laminar flow, corrugated flex line = turbulent flow. I like laminar flows.

 

[Mr tee]

Di-electric unions are pretty much worthless.

I can't understand copper flex in earthquake country. They are only flexible when new and if you don't bend them too many times. Once they harden up they are brittle. Our little neighborhood plumbing shop in Southern California sold over 1,200 in three days after one quake, and it would have been more if we could have gotten them. We had to put a per customer quantity limit on them, people wanted to buy all we had. This was in an area where the houses were originally (and mostly still) piped in galvanized. Of course nobody does gal any more, but we only saw one gal connection that broke and it was about rusted out and ready to go anyway.

 

[Jeff H Young]

why the union ? the flex line is your union

 

[JerryKrinock]

When you connect one end of a stainless steel flex with a brass nut to a copper main, and the other end of the stainless steel flex with a brass nut to a galvanized nipple on a water heater, that is a lot of dissimilar metal joints. Do we need any dielectrics in there?