[email protected] wrote on 07/07/2009 05:38:52 PM: > From: > > [email protected] > > To: > > "Discussion of precise time and frequency measurement" <time- > [email protected]> > > Date: > > 07/07/2009 05:40 PM > > Subject: > > [time-nuts] OT Euro/US plumbing was 14 tpi UNS die > > Sent by: > > [email protected] > > > [email protected] wrote: > >> Hi Chuck, > >> > >> Been living in Sweden my whole life. And almost exclusivly in houses > >> heated by circulating hot water through radiators. I have yet to spot an > >> O-ring. > >> > >> Where in Sweden did you see this strange system? > > > > Hi Bjorn, > > > > In the US, hydronic heat comes in a couple of flavors: The old fashioned > > cast iron radiators, fin/coil baseboard radiators, radiant baseboard, or > > steel radiators/towel warmers imported from the Europe. > > Your description does not enlighten me... there are all sorts > of radiators available here. > > > Most of the European systems are geared towards PEX tubing, and > > compression > > fittings... and untapered pipe thread with jamb nuts and O-rings. > > PEX tubing has been "certified", but Prisol tubing (ie soft bendable Cu > with plastic "coating") is much more common here. Cu tube joints are made > with "nut", "support cylinder" and a "squeeze ring". > > > Runtal, Cordivari, Wirsbro and Wesaunard are examples I have run into. > > It is actually Wirsbo... ;-) The others are unknown to me. > > > Do you install and repair systems? Or just live with them? > > I do minor changes to the house system. And I have accumulated more than > enough radiator heating seasons to know your "two seasons to > leak" quality must be a US craftmanship problem.
The relevant US pipe-thread standards are quite clear - straight threads are for mechanical connections only. For connections that must also contain fluids under pressure, one uses taper threads such as the ubiquitous NPT. Over the decades, I have lived in many houses, including my current house, with circulating hot water heat and cast iron radiators, and I have never had to redo a radiator connection. I've never had a leak, and most of these systems were old when I bought the house. If you have straight pipe threads going into radiators, there is an installer who should be made to re-do the job. Maybe he was an out-of-work electrician, and used rigid electrical conduit for pipe. Straight threads and O rings are seen only in hydraulic systems, not domestic water or heating systems, and the mating parts have correctly designed pockets to hold the O-rings. And they do not use jam nuts. One screws them together until they bottom. Joe Gwinn _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
