[TheForge] Re: Dielectric connections

[ries]

We are not talking about ALL electrical connections here- the bronze  
fitting Jerry is referring to is made, and sold, to solve a specific  
application between two metals.
When plumbing, you often come up with a situation where you need to  
connect black iron, or galvanized iron, to copper. These two metals  
are far enough apart on the galvanic corrosion chart that there may  
be, depending on the presence of salts in your water, corrosion if  
they are connected directly.
Bronze connectors are used, as they are about halfway in between steel  
and copper. Split the difference, and minimise the chances of failure.

This has been a time honored plumbing trick for probably 50 years or  
more.

No, it does not apply to capacitors, or to insulating 240,000 volt  
lines, or to other real electrical uses- but it is very common, and  
works quite well, to prevent galvanic corrosion in common plumbing apps.

Ries



On May 19, 2008, at 10:13 AM, Jerry Frost wrote:

I can't tell you the whats or whys of them. Perhaps they're like  
zincs? No, that'd be worse.

It's been a good 10 years since I put them in but distinctly recall  
being directed to and selecting them from the dielectric section and  
their being a redder metal than the normal brass fittings. The ones  
water side of the boiler are indeed insulated unions but the part that  
attaches to the iron pipe is the same redder than brass color.

Next time I'm in the plumbing shop I'll ask.

Frosty
-------------------------------
If it ain't forged
it ain't real.
Wrought iron is.
The FrostWorks

Meadow Lakes, AK.

From: "Andrew Vida" <osan at netlabs.net>


> A dielectric is by definition an insulator, so I am not clear on how  
> bronze may serve this role.
>
> If you tried to use a "bronze" dielectric in the manufacture of,  
> say, a capacitor, the results would be most interesting.  I  
> therefore remain perplexicated.
>
> Peter Fels & Phoebe Palmer wrote:

>> Jerrry: I'm confused, again.
>> I'd assumed that a dielectric element in a mixed metal assembly  
>> would be non-conducting, like plastic, ceramic,mica and so  
>> on...that wouldn't pass on current.
>> If you use copper, wouldn't that accelerate the corrosion on the  
>> iron?
>> What do i have wrong here?...pete f
>>
>> Jerry Frost wrote:
>>> Uh. Yes, bronze dielectrics. Are they made from something else?  
>>> Look like bronze but you know how copper alloys can fool ya.  
>>> There's one in every connection between copper and iron in the  
>>> house plumbing too.
>>>
>>> Frosty
>
> -Andy V.
>
> no .sig
> go .fig

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Ries Niemi
Industrial Artist
http://www.riesniemi.com/