CSST for low pressure steam line?

rhodebump

I have to replace a couple feet of 1" steam line feeding a radiator through some pretty challenging curves/angles. If CSST could be used, it would be so easy!

I know CSST is for gas, but when you think about it, that's also what black pipe is used for.

Any thoughts?

Yes, with the stupidity of my questions, someone should confiscate my pipe wrenches and pipe threaders!

Thanks!
Phillip

EBEBRATT-Ed

I suspect the outer covering would melt off. The inner core is made out of stainless steel so that would be good.

I would find away to pipe it in black.

I wouldn't use CSST unless it was a temporary connection

Alan (California Radiant) Forbes

EBEBRATT-Ed said:

I suspect the outer covering would melt off. The inner core is made out of stainless steel so that would be good.

I would find away to pipe it in black.

I wouldn't use CSST unless it was a temporary connection

Ditto

You can take shortcuts with plumbing. You can even take shortcuts with hot water heating. But steam is unforgiving. Don't take shortcuts. Guaranteed: It will come back and bite you in the tokus.

Bob Harper

No, it is not rated for steam so it could fail The corrugations would probably create a lot of water hammer. Those fittings aren't rated for temperature. They may do fine or the hoop stress may cause them to leak. I doubt the temps would be high enough to melt the polyethylene jacket. The pressure shouldn't exceed 5 psi worst case. We'll be listening to see if it works!

JohnNY

No. The condensate trapped in the corrugated ribs would cause noise and premature condensing of the traveling steam. You mentioned "curves and angles" so definitely not. If you had said a short section of vertical pipe, I might be inclined to think it would be ok for a short term fix. Also, the jacket's not a problem, but the tubing itself isn't rated for steam temperatures at all.
This is just a bad idea.

ethicalpaul

Well, the melting point of the tubing is 2400F so I imagine it could take it

My ignorant opinion (and it is!) is that there's some lawyer-related reason they kept the operating temperature range away from steam.

The corrugations aren't great, for sure, but I do love that stuff. I haven't worked with the jacketed kind, but I used plain corrugated stainless steel tubing in the "solar loop" part of a solar hot water system. So easy to cut, and had a cool little tool that would collapse a couple corrugations to hold the washered fitting on the end of the line. So strong and flexible.

Leon82

There rubber o-ring would probably get beat up pretty bad over time

hot_rod

We sold a version of that CSST for solar thermal installations. SolarFlex had a high temperature EPDM insulation over the bare stainless. Temperature and pressure would not be a problem.

Huge pressure drop with the corrugations, however.

There are some versions with a smoother inner wall used in hydraulic applications.

I like the outside the box thinking

Phil53

Soft copper might be a little better solution - like Gerry uses in his mini-tube installations.

rhodebump

Thank you all for the info! I will report back on this thread with what happens. I am going to try to do the black pipe, but it's a tough run.

EBEBRATT-Ed

@JohnNY

I don't think I would want to be in the same room when they put a 1500lb test on that stuff. It's not much more than tinfoil

mikeg2015

If it must curve and you are not inclined to open the wall, You might be able to use copper tubing, but you’d need to braze it like refrigerant lines and have to use a brass fitting on each end.

The mini tube system used copper tubing at I think up to 5psi if I remember correctly.