what is this please ? is it a valve ?

[Gary111]

Hi, I came across this, looks like a valve, but doesnt have a slot for a screwdriver.

 

[ktuludays]

Pressure reducing valve possibly

 

[terryplumb]

It's a check valve ( one way valve ).

 

[ianmcd]

It's a check valve ( one way valve ).

+1

 

[Mottie]

They found and removed something like that when I had my system converted to a sealed one. I think it was something to do with a previous gravity hot water system.

 

[Madrab]

Verifiable double check valve, what's it connected to, an outside tap?

 

[dal5band]

It is not an anti gravity valve - they are fatter and in a vertical pipe.