Uphill water or am I missing something

[andytw]

I often pass this bit of external plumbing in Cardiff and wonder what is going on. Any suggestions ? I think it is a BT building.

https://www.google.co.uk/maps/@51.4...ata=!3m4!1e1!3m2!1sR-ZIc0Bg3nu5my67ZeGNIg!2e0

 

[Madrab]

Possibly a secondary vent??

 

[Hugh Jaleak]

I'd suspect ventilation pipework, common on Victorian buildings, although it is unusual to see on a more modern building like that. Allows air behind water, the pipes should connect back to the stack inside where the sanitary appliances connect to the soil pipe.

Something is odd there though, as the larger pipes for a WC seem to go into the building on an odd level, doesn't look to be a floor at that level. Also the two pipes coming out below the vent pipes are too small for soil, can only be waste, but they are on the level I would expect the WC's to be....

 

[Newboy]

4" waste connections for S trap pans into void between floor and suspended ceiling on the floor below.

40mm/50mm - urinal wastes with venting back into the stack - reasonably common on commercial installations