Leak from Water pipe coupler

[Dark360]

Hello all,

I was fixing a stuck tap in my garden today, and after turning the isolator back on a coupler further along the pipe work started leak.

The coupler has hex nut screw so I decided to try tightening it, that didn't work and more water started to come out.

After isolating the water again, I fully removed the screw and its thread doesn't match the threaded hole in the coupler.

I have wrapped the screw in PTFE tape and put it back, but I would like to get a replacement screw.

I have attached a picture of the coupler (Sorry if that is the wrong term)

Can someone help please?

 

[ShaunCorbs]

Double check valve

https://www.NoLinkingToThis/p/double-check-valve-15mm/96336

 

[Dark360]

Double check valve

https://www.NoLinkingToThis/p/double-check-valve-15mm/96336

Thank you for your quick help.

 

[Keefy]

If you replace the old DCV with a new one make sure it's fitted inside and not outside. And with the arrow pointing in the direction of flow. Basic info but important.