Tech Corner

The TechCorner has been developed by the Copper Development Association to provide industry professionals with a targeted selection of white papers and answers to technical questions of interest to plumbers, installers, contractors and engineers. A glossary of technical terms that defines the meanings of specific terminology used in this section is also provided here.

Topics List

Soldering of Copper Alloy Flanges

The most important thing to understand when soldering copper alloy flanges is that they contain a huge heat-sink in the flange face itself. If the flange socket is not at a temperature high enough to allow the solder alloy to remain molten through the entire depth of the fitting socket, insufficient solder fill may occur... Read More

Commissioning and Disinfecting Copper Plumbing Systems

Once a copper plumbing system has been installed, the system should be flushed and commissioned for service. While there are no special requirements for commissioning and disinfecting a copper system, there are precautions that should be taken to ensure the commissioning and disinfection procedure do not damage the system... Read More

Copper Piping Systems and Acoustical Sealants

There are many situations in the built environment in which copper piping systems, as well as other piping, electrical, HVAC and necessary building services systems penetrate non-fire rated floors, ceilings and partitions. Depending on the size and complexity of the building, these penetrations can number in the tens of thousands... Read More

Soldering and Brazing Explained

For many years the two most common methods of joining copper tube and fittings have been soldering and brazing. These tried and true methods are in a number of ways similar, yet there are also several distinct differences that set them apart. This paper explains the similarities and highlights the differences between the two joining processes to help determine which joining method is most desirable... Read More

Can Copper Tube Be Used in Steam and Steam Condensate Piping Systems?

Everyone knows that copper tube has a proven history in use in a variety of applications, however a common question is "can I use copper tube in a steam system?" Just like in water systems, copper tube has long been used in both steam and steam condensate piping systems. The key to its successful use in either high- or low-pressure steam systems is in choosing the appropriate joining method for the service... Read More

How to Prevent Corrosion of Copper Tube in Underground or Buried Applications

Out-of-sight, out-of-mind. That's the phrase that comes to mind for all who have installed copper and copper alloy piping systems in buried, underground applications. An expectation well supported by the excellent corrosion resistance of copper alloys used in these applications. An expectation that may not be realized when this out-of-site, out-of-mind philosophy extends to the practices used in installing the system... Read More

Is It True That Electrolysis Can Cause My Copper Tube To Fail?

Electrolysis is an overused and misused term when applied to copper tube. True electrolysis, or electrolytic corrosion, as it is more properly designated with regard to piping, is caused by an imposed (external) stray DC current and virtually ceased to occur with the disappearance of the trolley-car that was powered by high amperage DC current... Usually, what people are really referring to when they say electrolysis is galvanic or dissimilar metal corrosion... Read More

Corrosion of Mixed Metal Fire Sprinkler Systems

This paper is in response to the many questions that are asked regarding automatic fire sprinkler systems using copper tube and fittings in conjunction with conventional steel pipe. The capability of mixed metals specifically to resist galvanic corrosion, is sometimes questioned. The concern expressed focuses primarily on composite systems where copper tube branch lines and cross mains are used in connection with steel pipe feed mains, risers and standpipes... Read More

Why Do I Have Blue/Green Staining Of My Bathroom Fixtures?

Green or blue water staining are names given to a general corrosive attack that on rare occasions occurs in buildings that have been plumbed in copper. In most instances this phenomenon manifests itself shortly after a new plumbing system is put into continuous service and then eventually goes away. Notice of this situation occurs, and concern generally arises, when it causes a slight blue or green discoloration in the water or, more commonly on surfaces that come in contact with the water such as plumbing fixtures. There are a number of processes that can cause this discoloration and staining, two of them much more common than the others... Read More

Is There A Problem With Embedding Copper Tube In Concrete?

It is completely acceptable to bury/embed both hard drawn and annealed copper water tube in concrete. Decades of satisfactory service experience with the use of copper tube for in-floor radiant heating systems, water distribution systems and snow melting systems attest to the compatibility of copper tube embedded, encased or in contact with concrete. It is also acceptable to run a copper water tube through a concrete floor or wall, provided that allowance is made for the lateral thermal expansion and movement of the tube and protection of the tube from abrasion... Read More

What Is Most Important When Designing And Installing Copper Piping Systems?

Copper tube and fittings have a remarkable track record for plumbing use. The ancient Egyptians are known to have used copper pipes for transporting water and, in modern times, copper tube has been used for over 75 years for plumbing in the U.S. It's a fact that the majority of problems with a copper piping installation can be prevented by proper design and installation practices. It's also true that a major cause of difficulty is erosion corrosion, a mechanically induced failure, which may be caused by number of conditions ... Read More