Yorkshire coupler moving oddity/magic trick

[shd1970]

Can anyone explain this please…..

I’ve cleaned up 2 x 15mm pipes, deburred and also the inside of a 15mm Yorkshire too
The cuts are clean

I push the Yorkshire on to the one pipe until I hear it click and can’t push it any further and hold it tight
Now I push the other pipe into the other end of the Yorkshire the same way until it won’t go any further, making sure the coupler doesn’t move

Now for the magic trick….i would expect the coupler to not be able to move, as both pipes were pushed in as far as they could go, right ?

Wrong

Somehow it can move a couple or 3mm towards the 2nd pipe that was inserted

Now I know it’s Sunday and I’ve had a pint but how is this so, I thought the pipe ends in the coupler virtually touched ?

Am I being thick ??

Surely if there is a gap within the coupler and the pipes don’t meet, surely that’s a trap to prevent smooth flow and a trap for sediment/rubbish to stick to ?

Any thoughts on this please ?

Give it a try if you have some 15mm and a Yorkshire knocking around

 

[kidgreen61]

Have another beer, problem will disappear

 

[shd1970]

Have another beer, problem will disappear

Tried that @kidgreen61 but nope, problem still exists
Do you use Yorkshires and if so have you tried it ?
I’ve used loads but never noticed this before

 

[denso13]

If fully inserted to start with, then it can't move.

 

[avonmouth]

Mark the pipe with a pencil at half the length of the fitting.you will then know if it's fully in.

 

[Madrab]

OK, just tried it - if the first leg is fully home to the groove and then the other leg is too then no, it doesn't move.

That is with 2 loose bits of pipe, if it's going onto a static pipe run then unless they are exactly the correct length and alignment then then may not fit exactly or pull out ever so slightly. Have you checked in the fitting, is it all clear too, no solder stopping it?

 

[shd1970]

@denso13 @avonmouth @Madrab - thanks for your replies

I've checked the coupler and no, there is no solder stopping the pipe before the midpoint
I'm using 2 scraps of 15mm that i've cut cleanly, and prepared like i would do a new joint to a shiny finish
I've checked with a magnifying glass and can see each pipe go in to the middle/centre point where the line is, but no further...they stop as they should
I've also tried other couplers in the pack and other copper also and they all do the same

This is bonkers !

I'd post a video if we were able to

 

[shd1970]

So quick update as I found what the issue is
Simply it seems to be due to the pipe slice that I’ve used
It’s a rothenberger the same as this one :

Pipe cutter

If you can see from the attached photo, it looks like it gives it a very slight chamfer on the end meaning it’s slightly passes the midpoint thus when you’ve done both pieces of pipe with the same cutter there is effectively a dip which is what allows the coupler to move back-and-forth

Considering I’ve used these many many times, it’s the first time I’ve noticed
I guess it’s not a major issue, but frustrating all the same

As you can see from my photo, the street elbow which I purchased has a completely flat cut end and when I put two of these onto the same coupler, it doesn’t move

So my question to you guys is what pipe cutter do you use And does it give you a nice clean cut with no chamfer ?

 

[denso13]

It shouldn't matter, if you fully insert the pipe, till it can't go any further, then the coupling shouldn't move back and forward.

My cutters leave a slight chamfer as well.

 

[shd1970]

hi @denso13

I think it absolutely does matter all be it it is minor
Even if the chamfer is 1 mm on both pipes then obviously that gives the range for 2 mm of movement effectively in that groove
As you can see from the photos I’ve attached the one where it has a street elbow and a nice straight clean cut. You can make out the midpoint within the coupling however with the cut that I’ve done on a separate piece of pipe because of the chamfer, the circumference is slightly less meaning it goes past that midpoint

It can be the only explanation in my head

Elbow/clean cut/midpoint visible


Chamfer

 

[Madrab]

Just as well that a 2mm flex in a solder fitting, in the famous words of Kryten, "don’t really amount to a hill of beans in this crazy cosmos"

 

[shd1970]

Just as well that a 2mm flex in a solder fitting, in the famous words of Kryten, "don’t really amount to a hill of beans in this crazy cosmos"

I hear you @Madrab
However, if you was doing a vertical joint, then it makes sense to make sure it’s pushed downwards so it doesn’t slip during the soldering process as you might not notice it

As you weren’t able to reproduce, can I ask what type of cutter you use, please?

 

[Madrab]

Yes, though a couple of mill movement wouldn't concern me with a straight solder ring fitting, as with an end feed the fitting will usually fill completely with solder top to bottom anyway.

As with others, a pipeslice is my go to, either that or a midget cutter but both will round out the end of the pipe, that was probably offset somewhat though when deburring, that may be why they didn't move. Again though a mill or 2 of play isn't going to cause any trouble.

 

[denso13]

hi @denso13

I think it absolutely does matter all be it it is minor
Even if the chamfer is 1 mm on both pipes then obviously that gives the range for 2 mm of movement effectively in that groove
As you can see from the photos I’ve attached the one where it has a street elbow and a nice straight clean cut. You can make out the midpoint within the coupling however with the cut that I’ve done on a separate piece of pipe because of the chamfer, the circumference is slightly less meaning it goes past that midpoint

It can be the only explanation in my head

Elbow/clean cut/midpoint visible
View attachment 390279

Chamfer
View attachment 390280

The pipes might be touching in the middle but the ends of the pipes are deformed so much that there is still a gap for the fitting to move. That's much more than a chamfer though, your cutters aren't right.

As Rob says though, it really doesn't matter anyway.