[time-nuts] OT Euro/US plumbing was 14 tpi UNS die

GandalfG8 at aol.com GandalfG8 at aol.com
Wed Jul 8 08:22:32 UTC 2009


In a message dated 08/07/2009 00:08:41 GMT Daylight Time,  
cfharris at 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





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