Pipes protruding from tenement roof - what are they?

[3phemeral]

We live in the top floor of a tenement building and spotted these pipes which protrude a fair bit through the building's roof - they are definitely pipes, about 22mm width, look to be copper, and they sound hollow when tapped (and can be moved/are light). They run through the attic and then inside our flat down the inside wall (to the left of the window looking from outside), and at least one then runs under our floorboards (I can't lift/follow where they go from there). We're wondering what, if any, purpose they serve now and whether they could be removed. Does anyone have any ideas? I haven't seen any protrusions similar to this in any other tenement flats, tho some buildings look to have short stubby pipes protruding (including the building to the left, just under the dishes).

The second and third pictures were taken in the attic, the final 2 are under the floorboards and then running down the wall (there are a few more running down the wall to the left of that, but I haven't made a big enough hole to photograph them all).

Thanks in advance!

 

[Notch7]

interesting

Ive never seen anything like that

if they were pressure relief I wouldve expected them to be vented through a side wall to the outside

22mm copper is typically used for water or gas, so they cant be vent pipes for like radon gas or air circulation as too small

look a bodge whatever they are

 

[Alastairreid]

Expansion pipes from hot water cylinders.

 

[3phemeral]

Expansion pipes from hot water cylinders.

Is that a pipe for excess hot water/steam to be removed from the old hot water system (using hot water tank/cylinders)? That sounds very plausible in any case!

 

[Alastairreid]

4 flats in the block?
If you have combi boilers the cylinders are normally removed.