In a message dated 08/07/2009 00:08:41 GMT Daylight Time, cfhar...@erols.com writes:
But I'm puzzled! First you tell me you have never seen an O-ring with a jamb nut in a heating system, and then you tell me that your system, presumably without any such O-ring seals, doesn't leak??? ------------------- I think that's because you're talking about different things. When Bjorn comments... "Cu tube joints are madewith "nut", "support cylinder" and a "squeeze ring"....... He's referring to a standard compression fitting, with the brass or copper "squeeze ring", more usually called an olive or compression ring, having tapered ends and being compressed around and into the copper pipe surface as the nut is tightened. Other than soldered joints, which are also still used, this is the standard fitting here for gas or water in domestic installations. When fitted properly, and they're very easily fitted, these shouldn't leak at all. If they have a downside it's that same thing that makes them work so well to start with, the ring bedding itself into the outer of the copper pipe, especially as there can be a tendency to overtighten despite warnings to the contrary. For the ring to be fully effective it needs to be installed over a "fresh" section of pipe. When working on existing systems, particularly those that have been installed for some time, it may be necessary to replace lengths of pipe, or at least cut back and insert a fresh short length in order to remove ends where the fittings have been previously installed I have also never seen an O-ring with jamb nut in a domestic heating system and don't think steel pipe has been used here in regular domestic heating systems since "central heating" took off in the 1960s/70s. Steel pipe, often it seems referred to as "gas barrel" even if not being used for gas, is still common in industrial situations but copper is the norm for gas and water in domestic situations with pipe sizes varying to suit flow and equipment fittings. Domestic radiator type water heating systems traditionally make use of 25mm and 15mm copper pipe but systems using plastic sheathed 10mm copper pipe are becoming more common, with the sheath being cut back to allow entry into the fitting.. As compression fittings are very much the norm here I'm surprised that you don't seem to have encountered them in the US. Is it possible that what is being supplied to the US from Europe is more dictated by US plumbing practices and regulations than by what we'd normally prefer to use ourselves?:-) regards Nigel GM8PZR _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.