purging with nitorgen while brazing

[mattmctree]

i usually purge my refrigeration lines with nitrogen before brazing to prevent carbonization . i know that this is the correct way to braze, however have been getting a hard time from my supervisor and fellow workers about doing so as they say it take too much time. How detrimental is it to the system if brazing is done without nitrogen? any thoughts?

[Admin]

You're probably working with old school R22 installers that don't understand how sensitive R410a systems are.  I'm assuming they pressure test their installations, and would have to setup the nitrogen tank regardless.  Problems may not occur until after the warranty has expired and may be why most people skip this step.

Connecting Refrigerant Tubing – Dry nitrogen must be purged through the tubing during brazing to keep oxides from forming. Flakes formed during brazing without a nitrogen purge will separate from the tubing wall to circulate with the refrigerant and oil, eventually forming restrictions.

Set the regulator for a low pressure – typically, 1 to 2 psi is recommended for this process. Flow the dry nitrogen into either valve pressure tap port, through the tubing and indoor coil, and out the other port while brazing. Nitrogen causes no damage to the environment.

After brazing, quench the joints with water or a wet cloth to prevent overheating of the service valve.

Check for Leaks – Use dry nitrogen to pressurize the tubing and indoor coil through the service valve ports located at the condenser. Check for leaks by using an approved bubble solution or other leak-checking method. Continue the process until the system has been determined to be leak free.
Connect the vapor-line and liquid-line pressure taps to a vacuum pump and micron meter.

[mattmctree]

we are working with brand new 410 systems. i know its extremely important which is why i do it but i get flack from others for doing it as they say it takes to much time and they dont care if the unit breaks down. Our customers are paying their hard earned money and should be getting a proffessional quality job which i try and give them. however other installers who arent apprentices or journeymen just dont care. its a tough spot