Induction Brazing a Threaded Bulkhead Fitting

Induction Application Objective

Brazing threaded bulkhead fittings can be a challenging process—especially when consistency, joint integrity, and repeatability are critical. In a recent application test, THE LAB at Ambrell demonstrates how induction heating provides a precise, efficient solution for achieving high-quality brazed joints in this type of assembly.

The Brazing Application Challenge

Bulkhead fittings are widely used to create secure, leak-proof connections through panels, tanks, or housings. These assemblies typically involve threaded components that must maintain tight tolerances and structural integrity after joining.

Traditional brazing methods, such as torch heating, often introduce variability. Uneven heat distribution, risk of overheating and damaging threads, inconsistent joint quality, and dependance on operator skill are among the issues. These issues can be costly and lead to rework, scrap, or field failures. 

Ambrell's Induction Heating Solution

To overcome these challenges, THE LAB leveraged induction heating, a process that uses electromagnetic energy to generate heat directly within the workpiece. 

Unlike flame-based methods, induction heating delivers:

• Localized, controlled heat at the joint

• Repeatable results from part to part

• Non-contact heating, eliminating open flames

Because the heat is generated precisely where it is needed, adjacent areas—such as threads or surrounding components—aren't impacted. 

THE LAB at Ambrell's Process

In this application, the goal was to braze a threaded bulkhead fitting assembly using a controlled, repeatable process.

Key elements of the induction setup included:

• A custom-designed induction coil to focus energy on the joint area

• Application of flux and brazing alloy to promote proper wetting and flow

• Controlled heating to bring the joint to the required brazing temperature

Heat was generated rapidly in the fitting by an Ambrell EASYHEAT 10 kW induction heating system. The brazing alloy melted and flowed into the joint through capillary action, forming a strong bond without melting the base materials.

Induction Results and Benefits

The induction brazing process delivered several key advantages:

• Consistent, High-Quality Joints 

• Protection of Threaded Features

• Faster Heating and Improved Throughput

• Reduced Operator Dependency
  
  
• Cleaner, Safer Process

Bulkhead fittings demand precision and reliability—any defect in the joint can compromise the seal. Precise heating with superior repeatability during this application led to strong, low-stress joints. This makes induction an ideal fit for this process. 

Interested in testing your brazing application? Ambrell offers free applications/feasibility testing from THE LAB.