titanium and copper/brass/or stainless steel brazing?

To all dear sirs,

I am vinay here on this fantastic site for we the refrigeration professionals and i am very happy to know this site which is proving very much helpful for me these days.

now we shall go to the following problem ,i am facing these days.

could any one from you solve my problem of

how to braze or weld the pure 'Titanium' and the copper or brass or even the stainless steel so that i would be able to fabricate the cooling coil for anodising application . the cooiling coil will be of titanium and all other refrigerant piping will be of copper.

is there any other material other than the titanium for such an application i.e. for anodising application with respect of the H2SO4 ( sulphuric acid 20 % by volume )?

expecting your reply

have a nice time always.

vinay

Friends,

Good Day

It seems that no one is either interested or able to solve my small query:(

:confused:

I hope within few hours or say days I will get this brazing or welding done with the help of all of you.

Till then Have a Nice Time,


Eagerly waiting ,

Vinay

Haven't really come across Titanium in the systems I work on - anyone else come across this?

I was unaware pure titanium was in use at all on refrigeration systems. I've dealt with heat exchangers with titanium coatings, but, fortunately for me, the connections were mechanical.

Never lit a torch on it, although I'd imagine that 56% Silver solder would've done the job, but, again, that was only titanium COATED. (SS, I believe)

Good luck with your search, vinay.

You will need an aerospace or oil (offshore) coded welding service. One of the local military airforce bases may have the equipment.

Titanium has a problem with chlorine based refrigerants due to Stress Corrosion Cracking we know we tried it. Welding the stuff will mean a large investment in the tools. Braze is a no no as the fluid will eat it both your nasty stuff and the refrigerant due to the electrochemical activity.

Copper to Titanium is also pretty bad on the electrochemical front. Frankly I's stick with 316L Stainless and have it stainless steel welded and then electrochemical stripped (not plated) to remove stress (corrosion) raisers. This is a process used by the offshore industry. As an alternative try Stainless with Swagelok couplings in 316 at least you will be able to replace bits as they fail. Monel metal is another option and Swagelok have that in their range but it costs arm, leg and wife plus small fortune.

I seem to recall copper/copper electro tin plated coils were used for this sort of thing or was that just salt water........:confused: