Medical Gas and Vacuum System Brazing

October 1, 2021 / 5 mins read

While certified pipe brazers are seldom hailed as heroes, it’s no exaggeration to say that the reliability of our vital medical gas and HVACR systems rests squarely on their shoulders

What is Brazing? Brazing is a joint created with a temperature over 450 degrees centigrade. If correctly done, brazed joints can be stronger than the metal parts connected but not as strong as a welded joint. Brazing’s advantages over welding are the need for relatively lower temperatures, and brazing will not melt the joined metal parts. Soldering does not create as strong a joint as brazing or welding. It’s important to note that brazing, unlike welding, is ideal for connecting dissimilar metals

Brazing in HVACR. Brazing is the technique of choice when repairing or installing HVACR systems. It is the best method for creating leak-proof connections that can stand up to high pressure and temperature conditions. Brazing is a necessity in HVACR.

Brazing in Medical Gas Systems. Soldered joints are unable to withstand the pressures and temperatures in a medical gas piping system. Brazing creates secure, strong joints vital to the needs of the medical profession. While soldering copper pipes in plumbing is the standard choice, it’s necessary to braze copper tube joints in both medical gas and refrigeration systems.

The Brazing Process. Since brazing makes use of a capillary action to fill the new joint with metal, the joint is often referred to as “making itself.” That said, brazing still requires a skilled and conscientious professional to follow six process steps to create a perfect joint. These steps happen in rapid succession in day-to-day work. Making a brazed joint is a quick process. Much faster than creating a linear welded joint.

Brazing process steps include:

  • Proper clearances and good fit
  • Cleaning the metals
  • Fluxing the parts
  • Assembly for brazing
  • Brazing the assembly: heating methods
  • Cleaning the brazed joint”

NITC Qualification Testing for Medical Gas Brazers. Since the early 1990s, NITC has qualified medical gas installers for brazing. At that time, the single practical test for brazing developed by NITC became the industry standard for the qualification of ASSE 6010 installers. Over the years, NITC has implemented additional brazing tests to reflect the latest requirements for brazing of medical gas and vacuum system piping to meet the stipulations of the NFPA 99 Healthcare Facilities Code and ASME Section IX Boiler and Pressure Vessel Code.