Quote Originally Posted by Martinm210 View Post
I can tell you that Tygon is NOT, I repeat NOT capable of handling household 50-80 psi water pressure..

I tried that once...luckily outside.. Think water balloon followed by my face receiving a good lesson learned.

I've also heard at least one story of someone damaging a radiator using household water pressure to flush it, so household pressure is WAY too much.

I believe Tygon 3603 is rated at 74F:
http://www.tygon.com/uploadedFiles/S...Lab-Tubing.pdf

7/16"x5/8" = 20psi Max
1/2"x3/4" = 25psi Max
1/2"x5/8" = 10psi Max..
3/8"x1/2" = 20psi Max

You obviously at least want thick walled tubing.

In operation, double DDCs likely won't subject the system to more than about 11psi, triples maybe 17psi, RD-30 maybe 14psi.

In practice I think it's been common enough to see dual DDCs that they are relatively tested to a comfort level, but triples are pretty new and not tested a whole bunch.

We don't know about the pressure rating on most parts so it's anybody's guess on that? Perhaps the manufacturers can start posting pressure specs??

Regardless, I suspect the weak point is the fitting/barb pull out on the tubing, especially anything that's been removed/put back together, and particularly with some compression fittings that have small barbs. A 1/2" tube at 17psi is receiving about a 3.5 lb normal force trying to pull the tubing off the barb. I'd be a little uncomfortable with that sort of pressure unless I had a standard barb and worm drive clamp.


I was reading the specs of my Swiftec MCP655 Variable Speed pump and its rated at 50 psi max. I'm using Tygon 7/16 with compression fittings and so far so good at max speed setting on the pump. Should I dial that down a notch or am I going to bust a fitting eventually?

Thanks.