Copper P-trap to bath waste

[robert.m.airside]

Dear DIY forum

I hoping someone can give me a steer.

I have replaced my bath and have a standard bath Click clack waste. My existing waste pipes are 35mm copper with a P trap. I removed the old BSP female x BSP male coupling which looks similar to Mcalpine T12B. I assume this is in place due to the difference in pipe diameter.

My questions relates to reconnecting the existing waste to new bath and keeping it water tight. The old coupling didn't have any internal washers etc. If I were to refit the old coupling should I put a washer in it?

In addition to this Should the copper P trap have a rubber washer around it where it connects in. It only had what looked like P.T.F.E tape wrapped around the lip.

McAlpine T12B

 

[terryplumb]

There should be a washer between the trap inlet and coupler ,and also between the coupler and waste fitting . PTFE tape would , however, seal the threads on coupler to waste fitting without a washer.

 

[Madrab]

The old copper trap has a flange where an old thick imperial fibre washer would have sat. I'm sure that would be long gone and the only way they could have sealed it then was with PTFE.

If you use gas PTFE tape then it'll let you away with more as it's thicker than standard tape.