What is the black threaded cap on filling loop for?

[WaterTight]

I've tried to find the answer online but can't. I'm guessing it might be a drain point allowing you to bypass the double check? And if so, do you turn off the valves, open the cap, attach a hose (half inch female flexi stylee?) and then when you open the valve above it you can let off the pressure?

And how is a water tight seal achieve on that cap? PTFE or a washer? This one is leaking a bit when I looked at it.

Thanks

 

[Deleted member 120897]

Possibly a test point? Part of the verifiable section?

 

[ShaunCorbs]

It’s for assembly and there’s a rubber oring best not to mess and replace the valve

 

[WaterTight]

Possibly a test point? Part of the verifiable section?

Does verifiable mean you need to be gas safe?

 

[Deleted member 120897]

Does verifiable mean you need to be gas safe?

Not a gas safe as it’s a water fitting, verifiable means it’s capable of being verified/checked.