Expansion vessel - connection type, immersion union ?

[myuserid]

Hello,
I'm in the process of replacing and installing new pipework. The expansion vessel for the combi has failed.
The vessel will be situated below the boiler - the only place I can tap into the 22mm return is near the floor, so I will be piping the vessel from underneath (if that makes sense!).

So I will require a 90 degree elbow into the vessel - I know I can shove a compression in there, but I'm not a fan of those. Prefer to solder. Can I use a 22mm immersion union (I can bend a 90 degree into the 22) and solder that in - or is there a fitting better suited ?

Also worth plumbing a valve into the vessel piping seen as these seem to fail quite often ?!

Cheers

 

[aptsys]

Don't add a valve. At some point, it'll get turned off.

 

[myuserid]

That's what I was thinking - but wras recommend adding a lockshield so you don't have to drain the system.
Hopefully I won't need to replace the vessel again before I sell

 

[Terrywookfit]

Fit a lever valve and remove the lever.
Also fit an oversized vessel if possible.