Where to PTFE? - One for the plumbers

[Jimmy Mack]

I'm replacing the boiler in my old stove, when I removed the pipe unions there was the remnants of some PTFE tape around the pipe shoulder... Is this common practice? I thought it would be around the male thread on the boiler? Though unlike an olive with a tapered shoulder, this junction is flat/ butted.

Some pics to give a gist of what I'm trying to achieve as I wait on the new boiler... I've stuck a cork in the pipe to stop the drip, drip, drip. ... Any excuse to crack open a bottle vino collapso [emoji23]

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[Robert]

that last picture looks like a tap connector to me. There would be a fibre washer between the shoulder on the copper and the iron pipe end. Nothing on the threads.

It does rely on the pipe end being a smooth flat face to seal on the fibre washer so someone could have wrapped over the washer with ptfe tape before fitting the nut hoping it would help it seal. It also needs the joint presented squarely.

I use this stuff on compression joints - https://www.toolstation.com/shop/Plumbi ... ant/p32502

all good so far. It also lubricates the threads so the joint does up easier.

 

[Jimmy Mack]

that last picture looks like a tap connector to me. There would be a fibre washer between the shoulder on the copper and the iron pipe end. Nothing on the threads.

It does rely on the pipe end being a smooth flat face to seal on the fibre washer so someone could have wrapped over the washer with ptfe tape before fitting the nut hoping it would help it seal. It also needs the joint presented squarely.

I use this stuff on compression joints - https://www.toolstation.com/shop/Plumbi ... ant/p32502

all good so far. It also lubricates the threads so the joint does up easier.

Thanks Robert, ah I'm missing a fibre washer. No sign of one...Perhaps a daft question Would it be able to take the heat?

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[DaveL]

that last picture looks like a tap connector to me. There would be a fibre washer between the shoulder on the copper and the iron pipe end. Nothing on the threads.

It does rely on the pipe end being a smooth flat face to seal on the fibre washer so someone could have wrapped over the washer with ptfe tape before fitting the nut hoping it would help it seal. It also needs the joint presented squarely.

I use this stuff on compression joints - https://www.toolstation.com/shop/Plumbi ... ant/p32502

all good so far. It also lubricates the threads so the joint does up easier.

Thanks Robert, ah I'm missing a fibre washer. No sign of one...Perhaps a daft question Would it be able to take the heat?

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It should handle the heat OK, the pipe is full of water and that should have a maximum temperature of 100 degrees C, the pipe maybe a little hotter but not much.

 

[9fingers]

I agree it looks a bit like a tap connector but they have a flat face where the fibre washer would go.
The fitting in the picture seems to have a taper seat which when new would possibly seal dry or with a smear of sealing compound.

That collar on the pipe could be some sort of compression olive but a special type that deforms to match a female taper

Does the female have a matching taper surface?

I took a cast iron boiler out years ages ago that had brass male and female tapers (non deforming) not sure if that was a standard but not seen them again since.

Whatever it is, I would not use ptfe tape but instead a sealing compound that will gap fill and harden with heating. Traditionally this would be Boss White but there are so many alternatives now and Roberts suggestion might be fine I don't know.
Apply generously but not so excess will squeeze out and impede the water flow. Tighten the fitting last of all when the rest of the pipework is supported but not forcing out every last molecule.
Refill the system being prepared to nip it up a bit tighter if it weeps. Final dryness might not be achieved until the fire is lit and pipes heat up.

Good Luck

Bob

 

[Jimmy Mack]

Cheers Bob,

I'll have a look for some sealant too...I actually picked up some of these (identical) when I thought I might have to replace the union... No sign of any washers in the packet [emoji848]


Just thought...I could of course call the manufacturer [emoji3]

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