best way to braze compresor rotolock valve

[kengineering]

On copeland condensing units we like to use braze type rotolock valves rather than the flare to prevent leaks. We have been using 45% silver rather than the 6% stick braze rod because it appears to be a disimilar metal. First question; What are the rotolocks made of ? Next what if anything would be a better choice of brazing material for this connection? I remember talking to a Harris rep. who said there is a high nickel content solder that works well for this but I never followed thru and that was many years ago. Can anyone shed some light here. Thanks, Ken

[lowcool]

stick with what your doing ken,blue tip or 45% silver is a strong weld given that theses points are one of the first to sustain vibration and radical temperature change,i wipe a bit of brown tip 15% silver over the weld afterwards as this takes care of any pin holes which may have formed and again improves strength of weld.as for nickel if it was that good i am sure we would have it now,as well as manufacturers.i still come across the odd new rota lock made of steel and pretinned for ease of welding.

anyone else came across nickel being used in refrigeration systems ?

[monkey spanners]

I don't like to use the flare ones either. I just give the pipe a good clean with a maroon scotch brite pad and wipe the pipe and valve with some automotive brake cleaner to get rid of any oil or grease and braze with 38% silver rods as these are what the wholesaler stocks.

Jon

[Grizzly]

I don't like to use the flare ones either. I just give the pipe a good clean with a maroon scotch brite pad and wipe the pipe and valve with some automotive brake cleaner to get rid of any oil or grease and braze with 38% silver rods as these are what the wholesaler stocks.

Jon

Automotive brake cleaner?
Not heard that one before Jon!
Sounds like a good tip?
Cheers Steve.

[lowcool]

think ill stick with wasting emery tape,the brake cleaner sounds a bit volatile to me.

[Bones]

I usually give them a good clean up with the old emery tape the pipes and rotolocks... use a little flux and brown tip solder.

[Robearoz]

I'm with you Bones - flux (most important) and brown tip (15%) for a hassle free joint. I've done many also without the flux but if something goes wrong it can be difficult to seal after - flux stops any problems.

[devlin maguire]

Brown tip,blue tip, what are they and who stocks them if they are any good
Devlin

[monkey spanners]

Brown tip,blue tip, what are they and who stocks them if they are any good
Devlin

I think blue and brown tip refers to a Austrailian classification of the silver content of the rods, generally i'd use 15% silver rods and no flux on copper plated steel valves and 38% (or there abouts) silver rods and flux on steel or silver coloured valves such as are common on L'Unite stuff.
If in doubt, 38% and flux, but the key to a easy braze is cleaning the pipe and valve, many rotalocks have a coating of grease or oil can be blown on them when you crack them open to let the ofn out if its a new unit so it pays to degrease them first. It also pays to crack them open a bit before brazing to stop them sticking shut as i'm sure you know!

Jon

[Temprite]

Hermitique units in Australia now have copper tails already welded to the rotor loks. Very easy.

[AUScooler:-)]

I think blue and brown tip refers to a Austrailian classification of the silver content of the rods, generally i'd use 15% silver rods and no flux on copper plated steel valves and 38% (or there abouts) silver rods and flux on steel or silver coloured valves such as are common on L'Unite stuff.
If in doubt, 38% and flux, but the key to a easy braze is cleaning the pipe and valve, many rotalocks have a coating of grease or oil can be blown on them when you crack them open to let the ofn out if its a new unit so it pays to degrease them first. It also pays to crack them open a bit before brazing to stop them sticking shut as i'm sure you know!

Jon

In Australia some wholesalers supply rods that have the tips of each rod colored. The color indicates the silver %. Thats why Aussies call them brown tip etc.