Go Back   Plumbing Zone - Professional Plumbers Forum > Plumbing Forum > General Plumbing Discussion

Thread Tools Display Modes
Old 01-28-2010, 11:45 PM   #1
2nd Generation Plumber
robthaplumber's Avatar
Join Date: Jan 2010
Location: Nashville TN.
Posts: 149

View robthaplumber's Photo Album My Photos
Default Dielectric nipples or not??

Dielectric fittings is the seperation of two dissimiliar metals right? I see how dielectric unions seperate the alloys with a plastic sleeve and rubber gasket. Could someone help me out with how the "dielectric nipples" that come with water heaters work? They are a galv. nipple with a plastic sleeve in the inner walls. How can it break the circuit if you screw a copper female adpt. on one end of the nipple and screw the other end in the water htr.? All the metals are still contacting. How can they be called Dielectric nipples? Some help?
Good Plumb'n aint cheap, Cheap Plumb'n aint Good
robthaplumber is offline   Reply With Quote

Warning: The topics covered on this site include activities in which there exists the potential for serious injury or death. DOES NOT guarantee the accuracy or completeness of any information contained on this site. Always use proper safety precaution and reference reliable outside sources before attempting any construction or remodeling task!

Old 01-28-2010, 11:49 PM   #2
Senior Member
rocksteady's Avatar
Join Date: Oct 2008
Location: Paso Robles, Ca.
Posts: 3,366

View rocksteady's Photo Album My Photos

They can call them anything they want. It's debatable whether dielectric unions work so I'm sure the nipples don't.

Rocksteady Plumbing
Serving San Luis Obispo County
(805) 237-7625 (ROCK)
rocksteady is offline   Reply With Quote
Old 01-28-2010, 11:51 PM   #3
Senior Member
Plumbworker's Avatar
Join Date: Oct 2008
Location: San Francisco, CA
Posts: 725

View Plumbworker's Photo Album My Photos

they dont do diddly..unless there a bradford white heater yank em and put brass or stainless

Last edited by Plumbworker; 01-28-2010 at 11:55 PM..
Plumbworker is offline   Reply With Quote
The Following User Says Thank You to Plumbworker For This Useful Post:
rocksteady (01-29-2010)
Old 01-28-2010, 11:53 PM   #4
Senior Member
AndersenPlumbing's Avatar
Join Date: Jan 2010
Location: Aurora, IL
Posts: 458

View AndersenPlumbing's Photo Album My Photos

I never use dielectric unions, they suck. I have yet to see one that isnt almost corroded or rusted shut after 5-10 years.

I use 7/8" X 3/4" FIP brass compression adapters.
AndersenPlumbing is offline   Reply With Quote
Old 01-29-2010, 12:07 AM   #5
since '85 /w G. Smiley
Join Date: Jan 2010
Location: Placerville, CA
Posts: 91

View plumbrsteve's Photo Album My Photos

used to have to use dielct coups, not unions, to connect ridgid lp lines from house to tank preventing lightning strike on house making the propane tank explode. that's it! i'm calling the mythbusters
plumbrsteve is offline   Reply With Quote
The Following 3 Users Say Thank You to plumbrsteve For This Useful Post:
Miguel (01-29-2010), ROCKSTARPLUMBER (01-29-2010), TheSkinnyGuy (06-09-2010)
Old 01-29-2010, 12:38 AM   #6
Protech's Avatar
Join Date: Sep 2008
Location: Polk County, Florida
Posts: 8,259

View Protech's Photo Album My Photos
Send a message via Skype™ to Protech

They are not Die-electric in any way. They just have a plastic liner which is supposed to hold the water way open. It does nothing by way of stopping galvanic corrosion.

They work ok if you use a brass female on the top and bottom it out so that the brass seals up against the plastic liner. While not truly die-electric, that method will at least hold the waterways open. The best method is to insert pex dip tubes inside the nipples and cut the one on the hot side so that it only protrudes about 1" into the tank. The flang at the top of the dip tube provides an even better seal against the brass female. When done this way there is zero flow loss from galvanic corrosion. It may also improve tank life but I have no evidence to support that yet. Only theory.
Protech is offline   Reply With Quote
The Following 3 Users Say Thank You to Protech For This Useful Post:
Miguel (01-29-2010), robthaplumber (01-29-2010), service guy (01-29-2010)
Old 01-29-2010, 12:43 AM   #7
Senior Member
ChrisConnor's Avatar
Join Date: Dec 2009
Location: Georgia
Posts: 2,347

View ChrisConnor's Photo Album My Photos

They do keep the waterway open. That's alone is worth something.

I've replaced water heaters that were under warranty that were installed with galvanized and only four years old that were less than 1/2 open due to rust buildup.
ChrisConnor is offline   Reply With Quote
Old 01-29-2010, 12:48 AM   #8
Registered Member
Join Date: Jun 2009
Posts: 6,437

View TheMaster's Photo Album My Photos

Those nipples to keep people from putting copper adapters directly into the heater making the heater fail at the inlets. The nipples keeps that copper to steel connection above the people wont call and say their water heater is leaking and get it covered under a warranty. Copper to steel eats steel, more so in some water. i guess you also have the option of installing dielectric unions but I dont do either and I take the steel mipples out all together and and other crap i can find in there but the diptube.
TheMaster is offline   Reply With Quote
Old 01-29-2010, 09:14 AM   #9
Registered User
SlickRick's Avatar
Join Date: Sep 2009
Location: Gilmer, Texas
Posts: 8,090

View SlickRick's Photo Album My Photos

Somebody explain the difference in these dielectric waterways and the nipples in the w/h's. We used ones similar to these when running Vict. galv. mains and transitioning to copper in commercial projects.

Last edited by SlickRick; 01-29-2010 at 09:46 AM.. Reason: OOPs forgot to post attach.
SlickRick is offline   Reply With Quote
Old 01-29-2010, 06:52 PM   #10
Senior Member
RealLivePlumber's Avatar
Join Date: Jun 2008
Location: NJ
Posts: 3,067

View RealLivePlumber's Photo Album My Photos

Would it be better to have a 2" brass nipple in the steel tank, then a c x f adaptor, to copper tube?

Why wouldn't the manufactures just put brass nipples in, instead of steel?
You can make it happen, you can watch it happen, or you can wonder wtf happened.
Phil Harris 2009
RealLivePlumber is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Dielectric Unions 3KP General Plumbing Discussion 19 01-15-2010 12:31 AM
lube for pipe nipples gplumb Plumbing Tools and Equipment 13 12-24-2009 12:56 AM
Dielectric leak Airgap Plumbing Pictures 18 12-14-2009 08:39 PM

All times are GMT -4. The time now is 03:24 AM.

Copyright 2000-2014 Escalate Media LP. All Rights Reserved
Our Pro Sites Network | | | | |

Search Engine Optimization by vBSEO 3.6.1