Plastic Barrels again!

[aamcle]

Ok, I think I understand your assembly.

You have a flat nitrite washer between the top surface of the lid and the bottom of the flange section of the post and this forms the gas seal.

I started using silicon mastic when I was building my own systems, recirculating biab, a rather nasty BM inspired system ((Ausi Next-gen build) and a Counter Top Brutus Twenty if you use it properly taps and such mounted on a Stainless vessel don't move they feel as solid as they would if they were welded on.

 

[Buffers brewery]

Talking of o rings and nitrile washers, I prefer to use dowty type seals on the outside of the lid topped up with a smear of sealant (belt and braces). The dowty washer lets you tighten the post down hard and provides a seal as well. I use a smear of this around the sealing surface….
https://www.screwfix.com/p/fernox-ls-x-leak-sealer-50ml/23614…for good measure. You could use the sealant on the tap thread as well if you wanted.

 

[RoomWithABrew]

Ok, I think I understand your assembly.

You have a flat nitrite washer between the top surface of the lid and the bottom of the flange section of the post and this forms the gas seal.

I started using silicon mastic when I was building my own systems, recirculating biab, a rather nasty BM inspired system ((Ausi Next-gen build) and a Counter Top Brutus Twenty if you use it properly taps and such mounted on a Stainless vessel don't move they feel as solid as they would if they were welded on.

Yes I have the arrangement on the top of my King keg, of flat washer instead of oring because of it's proximity to the edge of the lid.
My other post connections on fermentasaurus and kegs are with the oring instead of flat ring.

You do appreciate though that your post isn't assembled correctly ? it's not done up right and this effects the way the oring works inside the post.

 

[aamcle]

It's a Nasty Chinese post and to seal it I have to double up on O rings. That does seal