Correct Placement of P-Trap (Now Solved)

bjorn_toby_wilde

No.  As you look at that left hand fitting it has an inner and outer ring (don’t know how else to describe it). The thread is on the outside of the outer ring.

The pipe on the right pushes into that end to the fitting between the two rings then just tighten the nut (collar).

The thread will match. It’s all standard.

WIAWSNB

Hopefully.
But I didn't expect that screwed collar on the existing RH fitting - I thought it would be plain pipe.

bjorn_toby_wilde

I think it is if you look closely.

I didn’t explain it very well but take a look at the difference between a traditional fitting (1st pic) and that McAlpine fitting (2nd pic). The McAlpine has an inner section that fits inside the pipe.

tommybuk

WIAWSNB said:

tommybuk said:

Hi Folks, me again

Anyone know the part I need to connect the P-Trap to the down waste pipe? Seems like a male to male type situation.

The end that connects to the outside end is fine.

thanks 

Tommy 

I didn't expect that! 
The original fitting there looked like a conventional 'compression' elbow. But that screwed collar is part of the right hand fitting?
The thread on the U trap doesn't match that collar?

Hi WIAWSNB

No the lip on the pipe on the right prevents the collar from reaching the Trap.

The second photo shows how far the collar will go (not enough to reach the thread)

cheers

Tommy 

tommybuk

bjorn_toby_wilde said:

That looks right to me. The waste pipe pushes into that end of the trap, then do up the nut to compress that black sealing ring.

Have you tried it?

Hi Bjorn

Yes have tried the collar wont reach the thread 

cheers 

Tommy 

tommybuk

Also I know the second photo looks like they’re not lined up correctly but even when they are the ‘inner’ pipe on the trap is the exact same diameter of the pipe on the right and this prevents the screw collar from reaching.

Cheers

Tommy 

WIAWSNB

tommybuk said:

Hi WIAWSNB
No the lip on the pipe on the right prevents the collar from reaching the Trap.
The second photo shows how far the collar will go (not enough to reach the thread)
cheers Tommy 

Thanks. Yes I can see the issue. The original setup isn't as I imagined - sorry 😔 
I expected the fitting that goes on to the the darker, exiting, waste pipe to have been a separate, individual 'elbow'. So, when you removed it - as you have - I expected that vertical pipe on the right with its bend to be just that - a pipe! In which case, it would likely have slipped in to your new U trap, and all would be good.
Instead, that vertical pipe is part of a larger fitting that included the elbow, and has that screwed collar as part of it. Rats.
Q - can you examine that collar closely, and check that it does not come off in any way? 
I'm trying to think of a solution that doesn't require you to buy a few inches of 40mm pipe!
See that vertical pipe - could you unscrew and remove it fully so it can be examined more closely, please? Q - see the raised flange at its end which holds the O-ring? If that were removed - cut off using a hacksaw or similar, would the resulting plain end now fit in the U-bend fitting? Ie, would it be a suitable diameter - nigh-on 40mm O/D - and would it be long enough to insert?
Welcome to the world of plumbing, rarely as straightforward as it should be. But, you'll get there :-)
Worst case is that you'll need a length of pipe, and a push-fit elbow. But, let's see.

bjorn_toby_wilde

WIASWB is right.  I think you’ll need to undo the nut where the blue arrow is, fit a sort piece of vertical pipe (to get everything to line up), a pushfit or compression elbow, then another very short piece of pipe into the trap.

Before you do anything with a hacksaw, could we see a photo of the end where the blue arrow is, all undone?

WIAWSNB

Could you do as btw suggests, first, and let us see what you have?

Could you also confirm, please, whether the inside of the RH pipe diameter will fit over the protruding part of the new LH fitting, as shown? And, is it snug?

stuart45

It looks to me like a telescopic, swivel trap might work better if it was put where the blue arrow is.