So löten Sie Kupferrohre erfolgreich: Tipps und Techniken


When it comes to plumbing, brazing copper pipes is a popular method for joining two pieces together. Brazing involves melting a filler metal into the joint, which has a lower melting point than the adjoining metal. This creates a strong bond between the two pieces, making it a reliable method for joining copper pipes.

Before you begin brazing, it’s important to have the right tools and materials on hand. This includes a torch, filler material, flux, and a round file to remove any burrs on the pipes. You’ll also need to ensure that the pipes are clean and free of any debris or moisture, as this can impact the quality of the joint. Additionally, it’s important to consider the thickness and pressure of the pipes, as this can impact the melting temperature and joint strength.

When brazing copper pipes, it’s essential to follow proper safety protocols, such as wearing protective gear and ensuring proper ventilation. It’s also important to note that there are different types of brazing, such as silver soldering and copper-phosphorous brazing, which have different melting points and filler materials. By following the guidelines set forth by the American Welding Society and the manufacturer of your brazing alloys, you can ensure a successful joint that will stand the test of time.

Understanding Brazing Copper Pipes

Was ist Hartlöten?

Brazing is a process of joining two or more pieces of metal by heating them to a specific temperature and applying a filler metal that melts and flows into the joint by capillary action. Brazing is commonly used in plumbing to join copper pipes and fittings.

Why Brazing Copper Pipes is Necessary?

Copper pipes are widely used in plumbing for water supply systems and HVAC systems due to their durability and excellent heat conductivity. However, these pipes need to be joined together to create a continuous pipeline. Brazing copper pipes is necessary because it creates a strong, leak-proof joint that can withstand high pressure and temperature.

Hartlöten vs. Löten

Brazing and soldering are two different processes of joining metals. Soldering is a process of joining two or more pieces of metal by heating them to a lower temperature and applying a filler metal that melts and flows into the joint. Brazing requires a higher temperature and a different filler metal than soldering. Brazing produces a stronger joint than soldering because the filler metal has a higher melting point and can fill larger gaps between the joint.

When brazing copper pipes, the most commonly used filler metal is silver solder. Silver solder is an alloy of silver, copper, and zinc. The melting point of silver solder is between 1145°F and 1205°F. The brazing temperatures for most of the brazing alloys used to join copper piping systems are roughly between 1150°F and 1550°F.

Materials and Tools Required for Brazing Copper Pipes

To braze copper pipes, you will need the following materials and tools:

  • Copper pipes and fittings
  • Silver solder
  • Fluss
  • Fackel
  • Flame tip
  • Cleaning brush
  • Schmirgelleinen
  • Pipe cutter
  • Deburring tool

Before brazing, it is important to clean the joint thoroughly with emery cloth and a cleaning brush. After cleaning, apply flux to the joint to prevent oxidation during the brazing process.

Gemeinsame Stärke

The strength of a brazed joint depends on several factors, including the quality of the joint preparation, the amount and distribution of the filler metal, and the temperature and duration of the brazing process. A properly brazed joint can achieve a joint strength that is equal to or greater than the strength of the base metal.

In conclusion, brazing copper pipes is a necessary process in plumbing to create strong, leak-proof joints that can withstand high pressure and temperature. With the right materials and tools, you can create a strong and durable joint that will last for years.

Preparing the Copper Pipes

Before brazing copper pipes, it’s essential to prepare them properly. This will ensure a strong and reliable joint. The preparation process involves cleaning the pipes, reaming, and deburring.

Cleaning the Pipes

The first step in preparing the copper pipes is to clean them thoroughly. This will remove any dirt, grease, or oxidation that could affect the brazing process. You can use an abrasive pad or a round file to clean the outside of the pipes. Make sure to remove any burrs or sharp edges.

To clean the inside of the pipes, you can use a cleaning brush or a reaming blade. Insert the brush or blade into the pipe and rotate it several times to remove any debris or corrosion. You can also use a cleaning solution to help dissolve any stubborn dirt or oxidation. Rinse the pipes with clean water and dry them with a clean cloth.


Reaming is the process of enlarging the end of the pipe to ensure a proper fit with the fitting. This will also remove any burrs or sharp edges that could affect the brazing process. You can use a reaming blade or a deburring tool to ream the pipes.

Insert the blade or tool into the end of the pipe and rotate it several times. Make sure to apply even pressure to avoid damaging the pipe. Check the fit of the pipe with the fitting to ensure a proper fit.


Deburring is the process of removing any burrs or sharp edges from the outside of the pipe. This will ensure a smooth surface for the brazing process. You can use a deburring tool or an abrasive pad to deburr the pipes.

Hold the tool or pad against the outside of the pipe and rotate it several times. Make sure to apply even pressure to avoid damaging the pipe. Check the surface of the pipe to ensure a smooth and even surface.

By properly preparing the copper pipes, you can ensure a strong and reliable joint. Make sure to clean, ream, and deburr the pipes before brazing them. This will help you avoid any issues and ensure a successful brazing process.

Selecting the Right Brazing Rod

When it comes to brazing copper pipes, selecting the right brazing rod is crucial for a successful joint. Brazing rods come in different alloys, and each alloy has its own unique properties. In this section, we will discuss the different brazing alloys and which one is best suited for your project.

Brazing Alloys

Brazing alloys are made up of different metals, including copper, silver, and phosphorus. The composition of the alloy determines its melting point, strength, and other properties. When selecting a brazing alloy, it is important to consider the type of joint you are making, the temperature of the operation, and the desired strength of the joint.

BCup Brazing Alloy

BCup brazing alloy is a popular choice for brazing copper pipes. It is a copper-phosphorus alloy that melts at a lower temperature than copper, making it ideal for brazing copper pipes. BCup brazing alloy has excellent flow characteristics and is self-fluxing, meaning it doesn’t require additional flux to create a strong joint. It is also corrosion-resistant and has good electrical conductivity.


Silver brazing is another option for brazing copper pipes. Silver brazing alloys are made up of silver, copper, and other metals. Silver brazing offers high strength and is ideal for joints that will be subjected to high stress or pressure. However, silver brazing requires a higher temperature than BCup brazing alloy and requires the use of flux to create a strong joint.

When selecting the right brazing rod, it is important to consider the specific requirements of your project. BCup brazing alloy is a good choice for most copper pipe brazing applications, while silver brazing may be necessary for high-stress joints. Always refer to the manufacturer’s instructions for the specific brazing alloy you are using to ensure a successful joint.

Applying Flux and Brazing Copper Pipes


Before brazing copper pipes, it is essential to apply flux to both pieces of copper. Flux is a substance that can be used as a solder to join metals. It flows easily between two surfaces and creates a strong bond when heated. Flux is often used on a brazed joint because it melts copper and copper alloy quickly and evenly, making it easy to join them together.

There are several types of fluxes available in the market, including paste, liquid, and powder fluxes. You can choose the one that suits your needs the best. However, it is essential to ensure that the flux is compatible with the filler material you are using.

To apply the flux, use a brush or a flux applicator. Make sure that you apply the flux evenly on both sides of the joint. Do not apply too much flux, as it can cause the joint to weaken.

Brazing Copper Pipes

Once you have applied the flux, it is time to start brazing the copper pipes. Brazing is a process of joining two pieces of metal by heating them to a temperature above their melting point and then joining them using a filler material.

To start brazing, light up your torch and adjust it to a neutral flame. A neutral flame is a flame that has an equal amount of oxygen and acetylene. It is essential to have a neutral flame to prevent the copper from oxidizing and ensure that the joint is strong.

Next, heat one side of the joint until it feels hot for about two minutes. Then, apply the brazing material to the joint. The filler material should melt and flow into the joint due to capillary action. Capillary action is the ability of a liquid to flow in narrow spaces without the assistance of, or against, external forces like gravity.

Reheat the joint with the oxyacetylene torch if necessary to ensure that the filler material melts and flows into the joint completely. Allow the brazing material to cool before running water through it.

It is essential to note that brazing copper pipes require a heat source that is strong enough to melt the filler material. Therefore, it is crucial to select the right torch and heat source for the job.

In conclusion, applying flux and brazing copper pipes require attention to detail and precision. By following the steps outlined above, you can ensure that your joint is strong and leak-free.

Finishing the Brazed Joint

Once you have brazed the joint, it is time to finish it off. This involves cooling the joint and cleaning it.

Kühlung des Gelenks

After brazing, allow the joint to cool naturally. Do not quench it in water as this can cause thermal shock and damage the joint. The cooling process can take anywhere from a few minutes to an hour, depending on the size of the joint and the amount of heat used during brazing.

Cleaning the Joint

Once the joint has cooled down, it is time to clean it. Use a sand cloth or wire brush to remove any excess brazing material or flux residue from the joint. Be sure to wear gloves and safety glasses during this process as the brazing material can be sharp and dangerous.

When cleaning the joint, pay special attention to the inside of the joint where the brazing material has flowed. Use a wire brush or sand cloth to remove any excess material from this area. This will help ensure that the joint is smooth and free of any obstructions.

After cleaning the joint, inspect it carefully to ensure that it is free of any defects or imperfections. If you notice any problems, you may need to re-braze the joint or make other repairs.


Finishing the brazed joint is an important part of the brazing process. By cooling the joint properly and cleaning it thoroughly, you can ensure that it is strong, leak-proof, and free of any defects. With a little practice and the right tools, you can become an expert at brazing copper pipes and joints.


Brazing copper pipes is a reliable and effective method for joining copper pipes. It creates a permanent connection that is resistant to corrosion and vibration. Brazing also requires much higher temperatures than soldering, which means that it is better suited for larger diameter pipes and high-pressure applications.

To ensure a successful brazing process, it is important to prepare the joints properly. This includes cleaning the areas to be brazed to remove any impurities such as oil or oxides. There should also be an allowance of 0.004 inches between the fitting and tube to allow for capillary action of the brazing filler metal.

When choosing a brazing filler metal, it is important to consider the brazing temperature. The brazing temperature should be below 760°C, and silver solders with lower melting temperatures are recommended for optimal results.

Overall, brazing is a great option for joining copper pipes in plumbing applications. It provides a strong, permanent connection that is resistant to corrosion and vibration. With proper preparation and the right brazing filler metal, you can ensure a successful brazing process and a reliable joint.

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Bild von Mark


Spezialist für automatische Lötmaschinen und Kühlzubehör

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