Difference Between Dielectric Union and Brass

Brass is a copper/zinc alloy, so a brass nipple qualifies as a type of “copper alloy fitting” that is cited as acceptable by the code. While a dielectric union (shown above) provides a break in electrical conductivity that theoretically would be best, most plumbers prefer a brass fitting.

1. Is Brass a dielectric union?
2. Do I need a dielectric union for brass to galvanized?
3. What's a dielectric union?
4. Is Bronze a dielectric?
5. Do I need dielectric unions?
6. Why do dielectric unions fail?
7. What metals should not be used together?
8. Is Brass better than galvanized pipe?
9. Why do you need a dielectric union?
10. Do new water heaters need dielectric unions?
11. What does a dielectric union look like?
12. Can you mix copper and black pipe?

Is Brass a dielectric union?

Brass is considered a dielectric fitting of sorts. It creates enough of a buffer between the steel in the tank and the copper water pipe to prevent electrolysis.

Do I need a dielectric union for brass to galvanized?

There is some controversy as to the effectiveness of dielectric unions, but the bottom line is that if you connect a copper pipe to a galvanized one, some plumbing inspectors are going to require one. Certain municipalities consider a brass fitting a suitable dialectic union, but others do not.

What's a dielectric union?

Dielectric Unions are used in commercial and residential applications to prevent accelerated corrosion and deterioration in the piping system due to galvanic and stray current. It is installed between pipes made from dissimilar metal. We offer dielectric unions in a range of configurations, sizes, and materials.

Is Bronze a dielectric?

Bronze (dielectric connection is not required if installed with steel on either side) 2. As shown in the photo, external corrosion may not be present, and therefor is not a requirement for replacement.

Do I need dielectric unions?

In most jurisdictions plumbing codes require the use of a dielectric fitting when joining steel piping to copper or other metals; some plumbing jurisdictions permit use of a 6-inch brass nipple in this location as an alternative to diaelectric fittings.

Why do dielectric unions fail?

The unions fail whether or not the wires are installed to make continuity. If ordinary brass (copper and zinc) is in contact with water, particularly if it is chlorinated, some of the zinc can leach into the water.

What metals should not be used together?

Due to this, Albany County Fasteners recommends never using aluminum and stainless steel together. We also recommend using metals exclusively for maximum life. Stainless with stainless, aluminum with aluminum, brass with brass.

Is Brass better than galvanized pipe?

Brass piping provides a long-lasting material that does not rust in the interior, and it does not cause friction losses inside the pipe. Brass plumbing pipes are easier to thread than steel pipes and excellent for hot-water and large distribution systems, such as pump fittings, water tanks, and wells.

Why do you need a dielectric union?

Dielectric unions are used to join pipes made from dissimilar metals to avoid electrolysis, which leads to corrosion and pipe failure. This union is made from galvanized steel and lead-free brass. Plumbing codes in all states require the use of dielectric unions when connecting dissimilar metals.

Do new water heaters need dielectric unions?

Dielectric Unions

If either the tank nipples or the pipes are galvanized steel, however, and you are connecting them to copper, you must use a fitting called a dielectric union to make the connection. ... Both the hot and cold water pipes must have this fitting -- it's a code requirement.

What does a dielectric union look like?

A dielectric union is a pipe connection with a 1/16" thick plastic washer and a piece of rubber between the two. So jumper wires and clamps must be installed on either side of the union to make continuity between the pipes.

Can you mix copper and black pipe?

You should not connect black pipe to copper. Best to use a brass fitting in between or a a special fitting that will electrically isolate the steel from the copper.