A great lesson in how not to do somthing

[Mobieus_uk]

https://www.youtube.com/watch?v=uPxrLv1RjCU

if you know about flanges then the bit he is putting the sealant on is not part of the seal, the rasied bit on the middle is,lol

 

[micktheshed]

What a plonker: & he is demonstrating the 'correct' method?
Where do they find these people & why didn't someone with a bit of sense notice the obvious mistake?
Then again perhaps it's not so obvious to most people.......

 

[quixote]

No, he's done it right. If he were installing a paper or wirewound gasket then yes, he'd need to apply it to the raised face. With a flexible gasket compound, however, applying it to the raised face would result in leakage as the gasket material would be forced out as the faces made contact and the bolt preload applied. In this case, the gasket material will be compressed to fill the gap left between the flanges :thumb2

 

[solarman216]

No, he's done it right. If he were installing a paper or wirewound gasket then yes, he'd need to apply it to the raised face. With a flexible gasket compound, however, applying it to the raised face would result in leakage as the gasket material would be forced out as the faces made contact and the bolt preload applied. In this case, the gasket material will be compressed to fill the gap left between the flanges :thumb2

I think that that will depend on what the flange is sealing, if high pressure then with no sealant on the protruding part the pressure that will inevitably leak past those two surfaces will easily blow the gasket goo out (once set) if low pressure then fine, Rick

 

[quixote]

if low pressure then fine

Nope. Even on an extremely low-pressure application applying the sealant to the raised-face won't result in a seal. Assuming the faces are a standard machined-finish, any pressure at all will result in a leak once the bolting's fully pre-loaded

 

[solarman216]

Nope. Even on an extremely low-pressure application applying the sealant to the raised-face won't result in a seal. Assuming the faces are a standard machined-finish, any pressure at all will result in a leak once the bolting's fully pre-loaded

OK so what pressure will such a seal take, given that at the end of the day it is no more than a none compressed O ring although it will be bonded to each surface, have to say I am not so familiar with these types of 4 bolt flange just my logic comes into play, but I would say it would struggle at more than 100/150 psi, Rick

 

[kitchenman]

That flange looks like the flanges used on laundry equipment, that ran at around 100PSI which was the max setting of the boiler.
In the late 60's Boss White was the preferred compound for making a good seal.
Often with a composite gasket.
The only problem was getting the old Boss White off the flanges when you had to remake the joint .
It would have been nice to have that stuff shown on the video in those days

 

[quixote]

I would say it would struggle at more than 100/150 psi, Rick

I'd say you weren't far off the money at that, Rick. It might not even be rated as a pressure-retaining seal at all, when it comes to it. It may just be leak-proofing for a ambient pressure fluid-transfer system:nenau

 

[Mobieus_uk]

Not sure if I would trust at any pressure, but then Ive been always taught correct gaskets and paste, (Boss White is still used), but then I am getting old and new things are scary