What is this ?

[Rmichie]

Does anyone know what this is ? 
 

[TonyT]

Blow off pipe

[Rmichie]

Thanks Tony - is that normal to have that then?

[BotusBuild]

It's part of the safety features for closed hot water systems - yes, it is normal (and looks different depending on which plumber fits it 🙂 )

[Rmichie]

Thank you very much for your reply - greatly appreciated 

[TonyT]

It’s been fitted with round head screws. Clearly a decent install, as it’s not the gold screw countersink 1 screw does all brigade.

[SteamyTea]

Staining bar, used to be very common in Morrocan toilets.

Or was that just my experience.

[ProDave]

It is correctly behind a cage as when it blows off it could be near boiling water coming out.

[saveasteading]

Explain please as I have never seen this. A primitive safety valve where the joints are weak so that it comes apart?

[TonyT]

No like a gas boiler flue,l with a cage  at a certain height there to stop damage/ potential vandalism 

[ProDave]

16 minutes ago, saveasteading said:

Explain please as I have never seen this. A primitive safety valve where the joints are weak so that it comes apart?

The safety valve (actually two, over pressure and over temperature) are on the hot water cylinder .

 

This is where the discharge pipe leads to, it is just an open end of pipe, in this case turned back to face the wall.  If the blow of valves open, then it may be very hot water existing this pipe, so it is put behind a cage, and it must be somewhere visible.

[saveasteading]

Ok I see that. The bottom outlet is a few mm off the wall, so it splatters scalding water against the wall, safely and visibly.

 

I recall now seeing them in copper. An oversized pipe seems wise to reduce the pressure.