Are there any concerns with brazing central heating pipes? Will be purged with OFN whilst brazing. Many thanks.
I've used Silphos with oxy/acetylene on most of my copper pipe joints. Swaged joints. I pity the plumber that follows me. But then he will not be finding any joint leaks. PhilSo
You usually assoicated Silphos more with air conditioning and refrigeration than domestic plumbing. Rather posh for domestic plumbing here, french have a craze for brazing plumbing, rather than soft solder.
I had an abundant supply of Silphos and annealed copper tube. Why would I purchase inferior products if I didn't need to. I'm pleased with the work. The OP asked about brazing. Just sharing my experience. No harm, no foul. Why would you applaud the description 'idiot ' because I've offered advice? PhilSo
Thanks. This is for the replacement of my downstairs circuits that are buried in concrete. I’m looking for the most reliable solution. The plan at this point is to re-pipe with brazed joints laid in Armaflex class 0, and pressure test before backfilling. Kudox tell me that their panel rads are factory tested to 10 bar so the whole downstairs setup can be pressure tested I suppose.
“Most reliable solution” ? I use just leaded solder, or now mostly unleaded soldering on end feed fittings for heating systems. Never have any leaks and they will last. Just use good flux and proper soldering methods. Strange you are going to use Kudox panel rads, yet wanting to do best job. Kudox are not brilliant, but I guess they work
I agree. The pipes are critical to get right. But soldered joints can never leak or their joint deteriorate if soldered correctly. They will literally last a lifetime. If you are not used to soldering then you probably will not trust the joints.
Pressure testing on copper pipes isn’t really a definite proof of how good the joints are though. If solder was just holding on a edge of a fitting for example, the test would hold.
Soldering should be more than good enough if copper fittings and pipe are clean and fluxed well and just the correct amount of heat to keep solder as a liquid to keep capillary action working.
All the advice you've received on soldering is spot on. It will do the job well. However, if you have the opportunity to have the joints brazed, preferably with high quality copper tubing, then take it. A brazed joint is stronger than a soldered joint. I'm not criticising plumbers or soldering. PhilSo
Five times stronger I read. Anyway, thanks both for the input, collecting a range of views and advice is always helpful and valuable in getting to the final solution.
You don’t need any stronger than a properly soldered fitting though. Preferably unleaded solder. Near impossible to damage the joint - even if you hit them with a hammer. I have seen soldered joints leaking or showing signs of weeps, but that is poor workmanship