gas line for solar return and supply

DaimonVilppu

I've run into a few systems where a contractor used gastite or something similar. The trouble is that this contractor also used flex hoses that had a plastic liner that eventually overheats and bursts. On one of these systems I had to remove the fitting that connected the SS corrugated gas line to this hose. Now I can't get the gas line fitting to re-seal and can't find a replacement. I've tried the current gas line fittings and they are either too large (3/4) or too small (1/2). I also tried the caleffi fittings and those don't work either.

Do any of you have any suggestions? I'd rather not tell this client that he needs to replace his entire return and supply lines.....

I have a piece of the SS corrugated and can provide measurements if that means anything.

Thanks for the help.
Daimon

Jamie Hall

Those dang metric fittings...

kcopp

What is the brand? Parflex or Parker is long out of business. Ward are Omega still there but not compatible.

hot_rod

There are so many different metric sizes of the flex stainless out there, tough to find the original fitting. Is it a flare type or gasket seal?

How handy are you with a torch? I've found copper tube either fits inside or outside, braze or si-lflos carefully as that SS is super thin. Getting the ends to copper tube solves all the problems.

DaimonVilppu

Hmm.....I thought of brazing, but didn't think I would be able to make it work. I'll give that a try. I never trusted threaded fittings anyhow.

Thanks for the tip Bob.

hot_rod

The nice thing about the braze joint is you can then soft solder along side it.

I have done it with basic straight brass rod, and flux, very thin rod. Or the blue flux coated rod Safety-Sil 45FC from JW Harris.
Silver solder is crazy expensive these days.

A small brazing tip with a pencil flame, keeping most of the heat on the copper tube.

If they fit, I like the Gastite fitting, no gasket it just creates a flare like a brake fitting. And I see some CSST brand with a slip on fitting, almost like a SharkBite?

EBEBRATT-Ed

If this is natural gas or propane I wouldn't be soldering or brazing any part of it. Your post says "gas line for solar supply & return"........what are you working on??

If it's natural gas or propane I would identify the manufacturer of the flex and buy the correct fittings. If they aren't available ...replace the flex

Rich_49

EBEBRATT-Ed said:

If this is natural gas or propane I wouldn't be soldering or brazing any part of it. Your post says "gas line for solar supply & return"........what are you working on??

If it's natural gas or propane I would identify the manufacturer of the flex and buy the correct fittings. If they aren't available ...replace the flex

It is corrugated stainless being used for the supply and return in a solar thermal system Ed

DaimonVilppu

It worked! I did a little more research online, bought some 5% silver brazing rod and some high-temp brazing flux. It held on a 30# pressure test for more than 15 min. It may not be pretty, but it held and allowed me to solder to it. Beautiful.

Of course, while charging the system I found a leak somewhere else in the system and I also noticed that the expansion tank, which is to small, was installed on the PRV outlet.......

Looks like more work to get this system setup right.

Thanks for your help Hot Rod!