Pipework to Expansion Vessel - does water ever get into this pipework ?

[WhatNext]

Morning All

I have a quick question for you !

I have an external expansion vessel in my central heating system which has been t'd off the return line and has been mounted above the central heating pipework.

When the system is filled I realise that there is no way to bleed the air in the vertical pipework running up to the expansion vessel .

So what I was wondering was does the system water ever find its way into this section of vertical pipework or does this trapped air, in effect, become an extension of the expansion vessel ?

Many thanks.

 

[Madrab]

Does the system water ever find it's way into the vessel - Yes - Will there be trapped air - some probably.