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Old 16-01-2017, 03:33 PM   #9250
Join Date: Sep 2007
Posts: 393
Had my piping works done by Fortuna over the weekend.

The general quality of the work done by Fortuna was significantly better than the previous installer. The guys were quick and proposed a piping route that had the least number of turns (which minimizes bending) while still maintaining a nice, clean look for the trunking. I'll praise them at least for their general quality of work.

One problem that I identified was brazing in open air. This was for one 1/2" pipe that goes to the living room, i.e. the longest copper pipe in the entire system. I raised alarms to the workers about this, but the senior one mentioned that he'll purge the pipes with gas. I was under the impression that he was going to purge with N2, but what transpired was open-air brazing followed by a blast of R410a through the pipe. The worker assured me that the R410a purge would take care of any contaminants arising from brazing. That seemed rather unconventional to me; in fact I think that it might be illegal to release refrigerant openly into the atmosphere.

I was told by the worker that it was impossible to avoid brazing, but to me, it seems that he made a mistake by bending the pipe too early before routing it through the walls.

Anyway, I had a few interesting calls with Daikin's technical team as well as the Fortuna technical supervisor. Daikin told me that brazing for large, complex systems will certainly require an N2 purge, but for a simple system like in an HDB flat, brazing for 3 - 5 minutes shouldn't be a problem. The Fortuna supervisor told me that they had not provided an N2 purge as that would be an additional charge, and that the R410a purge would suffice.

I find this all very interesting. Every website out there suggests that it's fundamentally wrong to braze without an inert atmosphere in the pipe. From what Daikin and Fortuna have mentioned to me, it seems that it's an approved industry practice in Singapore to conduct small brazing works without N2 purging.

Perhaps I'm nit-picking because of what I've learned from this forum and other sites, but it seems wrong to me to condone such works.

I'm frankly quite tired to pursue this issue this any further, mostly because it's a pain to pursue reworks. (I've already replaced the old A/C installer with Fortuna and they had to rip out the work they had done.) I'm trying to convince myself that this is a minor point and shouldn't cause catastrophic failures in the system. I'll probably just ask them to purge the pipe once more using R410a before they install the FCU.

If there's anything that needs to be learned from all of this, put everything that you personally require in the contract.
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