Water keeps running out of pipe?

[ben100]

I’ve got this pipe outside which water is constantly coming out of the bottom as you can see. I’ve tried turning the blue fitting but it doesn’t stop it at all. I’ve got no idea why the PRV is there or what it’s for, can I just take it off & replace with a new one & turn it off on that?

 

[Gasmk1]

Yes you can fit a new one no idea as to why it’s there what does that pipe connect to

 

[ShaunCorbs]

To save it freezing and busting the pipe, prv will run / blow before the pipe does

Also need to tighten the push fit collar on it as it’s loose / slacking off

 

[ben100]

To save it freezing and busting the pipe, prv will run / blow before the pipe does

Also need to tighten the push fit collar on it as it’s loose / slacking off

Which prv valve do I replace it with? The one on there now says SYR 016. Also do I just undo the big nuts for that SYR 016 prv valve because on my one there's a part where there's that little nut with the tape in between it & the body of the valve whereas it doesn't have that in the pics of it when searching online.