Difference Between Dielectric Union and Brass (With Table)

There are many devices which are used in the houses. Knowledge of proper use of them should be known as these are required for crucial purposes. Such as devices used for tapping into water pipes.

For these purposes, you should be aware of the right tools that can solve the problems. Especially when it comes to water and pipe. As sometimes electrolytic reactions can take place, water is acting as the electrolyte. This results in metal corroding. And it is called galvanic corrosion.

To prevent this mishappening, few tools are used. These include Dielectric Union and Brass. While both of them are used for the same purposes, there are many differences among them.

 Dielectric Union vs Brass

The difference between Dielectric Union and Brass is that they both are used at different places for different purposes, while Dielectric is mainly used for connecting piping systems; Brass is an alternative option to this. Brass is mainly used underwater, where the chance of corrosion is high. Otherwise, also, they differ in terms of material used for the production of it, application and affordability, etc.

Dielectric Union is used to connect the two different types of metals; it can be for repairing the piping system or for any other purpose. It is mostly used for the water distribution system of commercial and residential areas and is made up of brass or galvanized steel.

Brass is the best alternative for a dielectric union for water distribution system problems. It is used where water is not of great quality as it is the area where mostly corrosion takes place as dielectric will not work with the corrosion. It is made up of an alloy of copper and zinc.

Comparison Table Between Dielectric Union and Brass

Parameters of ComparisonDielectric UnionBrass
UsedFor piping systems of different metalsAs an Alternative for dielectric unions for water distribution systems
ApplicationsCommercial and residential water distribution systemsRepair industry
Made up ofGalvanized steel and lead-free brassAn Alloy of copper and zinc
Preferred forFittings in the water distribution systems.Where water quality is poor.
AffordableMore affordableLess affordable

What is Dielectric Union?

It is a type of fitting used for the piping system where you have to connect two different metal pipes. It helps prevent any kind of leakage that can lead to big and crucial problems. It helps prevent the galvanic corrosion that can take place due to corrosion that takes place due to the presence of two different types of metallic pipes.

Electrolysis and deterioration mostly take place in the commercial and residential area, and that is the reason it is mostly used in this area, as the plastic composite of union’s clamping helps break the electrical continuity in the water distribution system.

A dielectric union has non-conductive fiber in its sleeve. That fiber surrounds the brass of the fitting. It was mainly made to use copper.

The voltage involved in galvanic electrolysis is not harmful. It is used and preferred by many people as it is suitable for most of the conditions and it is quite inexpensive for the purpose it serves.

This tool is required in every household, for example, for watering when a person has to join to pipes (especially pipes from different metals) if he is not careful enough, a huge blunder can take place.

What is Brass?

We are very familiar with the Dielectric Union, how it works and for what purpose it is required. For the places where a Dielectric Union cannot be used, Brass is the best alternative.

For example, earlier, it was discussed ho Dielectric Union was used for household pipes where generally water is of good quality, but what about the areas where the quality of water is not good? There Brass is used for the same purpose as the Dielectric. It is approved for working under the water in the water distribution system and is the best where there is a high chance of corrosion of the galvanized materials.

Brass is made of copper and zinc malleable alloy, and it not new in the market. It is used for many years. As the Dielectric Union was creating problems in the repair industry, then it was replaced with brass. IPS and NPT standards are used to manufacture the brass fittings and are very compatible with copper, PEX, and PE, and ipe or tubing.

It has a disadvantage that brass is very vulnerable to acidic water. Therefore it cannot be used anywhere near acidic water. Although it is expensive, for the benefits and high quality it provides, it is worth every cent.

 Main Differences Between Dielectric Union and Brass

  1. Dielectric Union and Brass are used for slightly different purposes. For connecting two different or dissimilar, or even similar pipes, Dielectric Union is the best choice, while brass is used as an alternative for water distribution systems.
  2. Applications for both of them are also different. For commercial and residential purposes of water distribution Dielectric Union is the option, and for the industry where repair for some piping-related work is done, Brass is the option.
  3. Dielectric Union is made galvanized steel or even lead-free is used in making process and brass in the alloy of copper and zinc both.
  4. Another difference between them is the presence of an elastomeric rubber gasket, which is present in Dielectric Union but is absent in Brass.
  5. Dielectric Union is mostly preferred for the fitting work in the water distribution system, while brass is the ideal choice for poor quality water where the chance of corrosion is high.
  6. Brass is more expensive in comparison. Therefore, it is less affordable. On the other hand, Dielectric Union is a much affordable option.


They are devices used for something related to water but have different properties and functions. Both of these tools or devices are approved for use in water. They are used for different purposes and sometimes at a different type of water. But before using any of them, the user must always understand the requirement and how these tools work as a little mistake can cost more. Although it is always the choice of the consumer, if the case is of electrolysis and pipe deterioration, Dielectric Union is always preferred as this tool avoids these little happenings. Except for them, there are also other devices used for some similar process/function.


  1. https://ieeexplore.ieee.org/abstract/document/884022/
  2. https://www.sciencedirect.com/science/article/pii/S0010938X67800908
  3. https://meridian.allenpress.com/rct/article-abstract/52/3/605/91081
2D vs 3D