I'd like to replace the compression nuts on the teflon tube that fits between the pump and boiler.
If I knew the exact size, I'd get them locally. What confuses me is that I believe that the tube has an OD of 6mm, yet the thread size on the fittings is 1/4", and probably BSPT. Am I to believe that the brass fittings are both metric and imperial at each end? It is more likely that the fittings are either both metric or english, not both.

Another way to solve the problem is to find the braided metal hose line with the fittings already attached. I am seeing pictures online that the V3 silvias come equipped with this type of hose. It looks superior than the teflon tube version, if only I could source that setup from somewhere.

thanks for any help-

ah
thanks for the order, I guess you don't need more answers?
Stefano

yeah, I think that I am set, and thanks...
As long as I can feed the new braided line into the newer OPV female fitting.
The braided line looks to have female ends on it, but its not a detailed image.
I'll wait and see what comes in the package.

But, just for curiosity's sake, what is up with the mix and match of metric, english and BSPT measurements with this setup? Geez!

YES it is a male in one end of the hose
and it is all BSPT (should.................)

You are correct in that the teflon tubing is 6 mm OD (ID is 4 mm and the length is 215 mm) but you're not going to find the "nuts" which capture that tubing locally.

As far as the size of the threads - - I have lots of tools to measure threads and I would still need something a little stronger than espresso to come up with the correct answer to that one. I could say M10 x 1.0 and I would be a little off; I could say 1/8"G (1/8-28 BSPP) and I would be a little off. For sure the thread size of the 90 ell that screws into the pump snout is 1/8"-28 BSPP and the thread size that screws into the original Silvia OPV housing is likewise.

If we're lucky, someone from Europe will read this and provide the answer. If you're into trouble with the hose and/or the fittings, I do have parts that would substitute.