I've noticed recently that my 15mm compression joints seem to leak more often than they used to. There seems to be a smaller region between "too loose" and "overtight" when doing them up.
Has the wall thickness of standard 15mm copper tube been reduced recently as an economy measure perhaps?
Robert
Not sure about that but I did overhear a chap a few doors away complaining that he thought the copper quality was crap nowadays and too soft to keep it leak free. Maybe it is the material?
Brian
than they used to. There seems to be a smaller region between "too loose" and "overtight" when doing them up.
an economy measure perhaps?
Which 'standard' copper tube are you buying? BS EN 1057 copper tube comes in three different recommended thickness of wall (0.7mm, 0.8mm and
1.0mm) and three more that are recognised but not recommended.Colin Bignell
than they used to. There seems to be a smaller region between "too loose" and "overtight" when doing them up.
an economy measure perhaps?
I'm not aware that it's changed recently. It certainly did in the 60's or 70's (it was 1/2" rather than 15mm in those days). If using an internal bending spring, you needed the right spring to match the spec of the pipe.
The pipe which I've bought recently seems to be harder - so maybe the olives don't bite as well. If you use softer olives (copper rather than brass) they might deform to the shape of the tube more easily and make a better seal.
often than they used to. There seems to be a smaller region between "too loose" and "overtight" when doing them up.
an economy measure perhaps?
Aha, thank you Colin. I hadn't realised there was a choice to be made. It is quite possible that the last batch I bought was 0.7mm wall and that I had 1.0mm before. Presumably the thinner one is cheaper.
In reply to Roger. yes the old 1/2" was much thicker but the OD was pretty close to 15mm so it can still be used. I have a small stock.
Robert
The wall thickness does vary according to the aplication but the outside diameter remains the same.
Some grades are not suitable for bending either. I suspect more to do with the hardness than the absolute thickness.
I seem to recall different 'tables' in the spec. Table X and table Y seem to ring a bell but I can't recall which was the bendable and which was not.
On Wednesday 13 February 2013 10:35 Roger Mills wrote in uk.d-i-y:
I use brass generally, and tighten to get a *slight* bite into the pipe (no way it can slip off then). It does take a fair bit of welly, so I usually mentally refresh myself by undoing the first joint and checking, then muscle memory seems to keep me going for the next batch.
But I agree that the hardness of copper pipe seems higher now than yesteryear.
On Wednesday 13 February 2013 10:31 Nightjar wrote in uk.d-i-y:
Bugger - wish I knew that 2 years ago...
That's easily changed. You soften (anneal) copper just by heating it (with a blow lamp or over a gas stove). You don't need to quench it (makes no difference with copper), but you can do so if it's useful to you to have it cooled quickly for handling, and that may reduce the time it has for surface oxidation at high temperature.
It hardens with vibration and bending (work hardening).
Most plumbing applications use half hard tube, but microbore normally uses fully annealed and for some applications fully hard tube is available. The harder the tube, the more difficult it is to bend for a given size.
That is from the older BS 2871:1972. Table X was thin wall tube - 0.7mm for 15mm tube. Table Y was thick wall tube - 1.0mm for 15mm tube.
Colin Bignell
I always put a smear of general purpose grease on the threads of new compression fittings which saves effort when tightening and stops that 'orrible screeching noise. Not aware of any difference in the minimal number of weeping joints over the years. I refuse to use sealing jollop as it makes reworking a nightmare once it has gone hard.
If by "sealing jollup" you mean stuff like Boss White, I agree. But LS-X
than they used to. There seems to be a smaller region between "too loose" and "overtight" when doing them up.
an economy measure perhaps?
Yeah, but Table X was half hard (general plumbing),
Table Y was soft annealed and came in coils
Table Z was hard drawn and wasn't suitable for bending.
I can't be arrsed to look up the BS EN modern equivalents.
That'll confuse him. That's the US standards.
Try this one;
Lots more info on that site.
There is table X pipe that is"half hard" and can't be bent, only used with fittings. The wall thickness is less. I've noticed some DIY places selling it.
No, Harry.
Table X was the standard plumbing tube, half-hard.
Table Z was the hard-drawn thin-walled tube that was not intended to be bent.
These standards (BS 2871:1971) are obsolete, some BS EN equivalent standards are used now.
One of the plumbers on another forum claimed to have bent Table Z tube regularly, having been supplied with it for contracts. He did seem to know his stuff, I don't think he was mistaken. I can't recall whether he annealed it first.
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