Is this an isolation valve or something else..

[GoodOne]

Hiya,

I bought a garden tap kit from toolstaiton, and it comes with this (pic below).

So, does any one knows what the purpose of this looks like isolation valve for?
Or it's not an isolation? Could i just by pass it?

Thanks!

 

[oilboffin]

It is a check valve it only let's water flow in one direction.Bob

 

[oilboffin]

You cannot by law by pass this it's to protect against back flow and not let polluted water into the mains potable supply,if the water supplier catch you without one you get busted big time.Bob

 

[seniorservice]

And there is never any reason to put PTFE tape on the threads of compression fittings. PTFE is only used on threads, where the thread actually makes the seal itself, eg radiator tails and male irons. On compression fittings, the nut and thread have no contact with the water inside - it's the olive that makes the seal. If anything, PTFE on compression nut threads could make the joint more likely to leak, as the tape bungs up the threads and may stop the nut screwing down enough to fully compress the olive onto the pipe.

 

[Agile]

But it can help to put a couple of turns of PTFE tape over the olive.

I do sometimes lubricate the compression nut threads with a little silicone grease as that enables them to do up tighter on the olive with less torque.

 

[GoodOne]

silicone grease

Do you mean "plumber's grease"?

 

[Agile]

My 500 ml pot says "Silicone Grease"!