I've been doing a lot of copper plumbing lately and have got quite
proficient at bending pipes using my pipe bender.
I have to run a 15mm pipe from floor to ceiling, and the wall is half
tiled. Therefore the pipe needs to accommodate the change in surface
depth (about 12mm) I think, as neatly as possible.
What's the easiest way of getting a close together "double-bend", or
"step" in the pipe? I have a bending spring, and a pipe bender, but am
not sure how to get the required two bends right next to each other.
Depends how tight you want to follow the step. You can get passover
bends that you could solder on. I just put in two slight bends with a
spring, but the gap between them was a hands-width so I could grip the
"other" side of the second bend.
There are instructional videos on the net - google for passover bend
tuition or something.
For the detailed take on pipe bending:
For a 1/2" offset though I would probably cut the pipe and use a pair of
45 degree end feed bends back to back.
On Mon, 13 Sep 2010 14:28:10 +0100, John Rumm wrote:
Beat me to it, that is an excellent document.
I'd have a go at two pulled bends it would look so much nicer.
Example 3 in the above shows a 50mm "step" in 15mm pipe using 30
degree bends. I suspect the "23mm back" will be in the first pulled
bend but I don't think that will be a problem.
Just had a quick 'n dirty play with some short offcuts. Managed to
get a 15mm offset with two bends of about 15 degrees, the inside of
the first bend is under the hook of the bender when pulling the
second and the offset takes about 50mm to happen. Done with care
rather than a rushed "bung a bit of pipe in the bender and pull
it"(*) should be possible to pull double bend with the required 12 or
(*) I actually did two, the first I didn't check that the pipe was
inline with the former of the bender for the second bend so although
I got the offset about right it wasn't flat.
Make up two sections of pipe with the required angles (45 degrees) and
cut off one end of each pipe as short as possible. Make sure the 'stub'
is straight enough to accept a straight end feed connector. Join the two
short ends with a straight end feed connector.
Using Ubuntu Linux
FYI, this bend would be called an "offset" or, informally a "dog-leg".
If you plug the numbers in, you get a distance between bends of 24mm,
which is virtually one flowing into the other.
So, you will struggle to get a 12mm offset dogleg into a 15mm pipe.
Better to put a 45 degree bend in the pipe and then use a 45 degree
elbow to do the other part of the dogleg, but you may find that you
still can't get your offset down to 12mm.
Another option would be to not bend the pipe, but to use low-profile
clips on the tiled area and standoff clips on the non-tiled area.
http://www.bes.co.uk/products/159.asp items 8729 and 6478.
Another option would be to use a 45deg elbow and a 45 deg street elbow.
Again, this likely would not give you an offset as low as 12mm.
http://www.bes.co.uk/products/148b.asp items 7984 and 7990
Have you considered coming in gently over a slightly longer run?
First bend of a few degrees at the tile boundary.
Second bend of a few degrees a bit further down when the pipe has come in
the required 12mm.
It may well look less obtrusive than a sharper bend.
No plan survives contact with the enemy.
[Not even bunny]
Practice. I've managed to do what you describe several times just using
a bending spring and my knee. It's easy if you are just doing one tube.
If you need two identical ones (hot/cold or flow/return) then it gets a
bit tricky and you need a good eye and the ability to apply controlled
After you've buggered it up a few times you get the hang of it.
Of course the difficult bit is getting both bends in the same plane.
The trick there is to plan it using one of the web guides on dog leg
pulling which give an idea of where to start pulling each bend based on
the radius of your pipe bender former, assuming a pipe bender is being used.
I've used some scrap copper to "calibrate" mine:
I have a mark in "Sharpie" ink on the former where the bend will start
and a number of marks (relative to a convenient fixed point on the other
moving part of the bender) of how far to pull for 22.5, 30, 45, 60, 67.5
and 90 degrees. It's not absolutely repeatable (cheap bender) but minor
discrepencies can be tweaked around the knee without a spring (we're
only talking a couple of degrees tweaking either way - much more and you
wreck the pipe).
If you are in a position to mark up the pipes with ink first and put
some marks on the former wheel, then it's possible to mark up two pipes
the same whilst straight.
That makes it fairly easy to get two identically bent pipes.
The harder bit I find is actually pulling the bends in to do what you want!
But if you can set up the job so that major tweaks can be achieved by
rotating the piece and cutting to length, the ability to bend precisely
becomes less important. Can't always be avoided, but a bit of careful
though sometimes finds a cheat.
Re: taps - if the object is to offset the pipe so it comes back towards
the wall, then use the same bend to bring the pipe more to the centre of
the basin too (ie 45 degrees +/- looking down from the top menaing a
bigger step in the dog leg than originally intended).
Basically this means that if you are out, you just swivel the pipe
around until it suits the clips spacing from the wall. It might not land
on the vertical axis you intended, but with both pipes bent the same,
the result will be symmetrical and thus look perfect :)
I've buggered up several metres of pipe practising! I did manage to get
my chrome right (with the cheat methods) though - didn't fancy wasting that!
Indeed. You have to do it by eye - though a bit of brute force with bare
hands can usually tweak it afterwards if it is basically right.
On Mon, 13 Sep 2010 22:12:20 +0100, Tim Watts wrote:
The OP wants to get the bends 'close together' with an offset of just
12mm. He doesn't say what he means by 'close together' but his intention
is to accommodate the step from a tiled section of wall to a section of
wall without tiles. This will require the distance between the bends
(according to my sample) to be about 2" maximum which might not be
achievable in a single piece of pipe unless the bender former is a very
See my earlier replies for my method which avoids the difficulty of
getting the bends in the same plane in a single piece of pipe.
Using Ubuntu Linux
A quick play earlier with some scrap and standard pipe bender gave
about 2" between two 15 degreeish bends and about a 15mm offset. That
was a very quick 'n dirty play, with a bit of care I think one could
produce a very acceptable result and smaller offset. It would look a
lot better than anything with fittings involved.
Thank you to all for taking the time to reply in such detail, and
thanks for an interesting discussion.
I should have said I needed to make two such bends for flow and
return, and routing the pipe differently is not really an option.
I deliberated over the best method, and almost bought myself a bag of
25 45 degree end feed connectors from Screwfix (there is a branch near
here), but in the end I used my pipe bender, and simply spaced out the
two bends a bit more than I would have liked. This achieved the 13mm
ish step over a distance of approx 2.5cm, not too far away from Dave's
figures above. I did have to be careful that the "pipe clamp" (I think
that's what it's called, the sort of hook device that holds the pipe
steady in the bender) didn't dig into the reverse bend, but I
protected the pipe with a bit of rag which allowed me to get the two
bends closer together than would otherwise have been possible.
It did need some manual tweaking to get the two pipes to match, but
that was no problem.
I have to admit I've never been much good with a bending spring (seems
to need superhuman strength to get the pipe even to move, let alone
form it to a precise bend!). Maybe I just need more practice on longer
pieces of copper so I can get more leverage!
Nope, not only you. Bending springs used to work well when the standard
copper pipe was thick walled (1.2mm) and fully annealed - then it was
fairly easy to get decent results that way. These days the pipe is what
is called "half hard" and thin walled (0.8mm), and that is not as easy
to do with a spring.
The general experience:
On Mon, 13 Sep 2010 23:21:24 +0100, Dave Liquorice wrote:
I tried to repeat your test with my pipe bender (Clarke - dual 15mm /
22mm) and got the same result as you got so it is certainly possible. Two
inches seems to be the smallest practical distance possible between the
bends without risking damage to the first bend by the tube stop. In fact
it isn't the size of the former (as I thought incorrectly) that limits
the offset size but how well one can measure the small angles involved on
a standard bender which is not a very precise tool.
I suppose would could have a specially designed bender with more precise
design and positioning of the tube stop to create these small close
doglegs but it would probably have very limited use and cost more than a
You must be a bit of a perfectionist to worry about the use of a single
end feed fitting which is only about 2mm more than the diameter of the
tube itself and barely visible when painted.
Using Ubuntu Linux
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