Compression blanking ...

[WaterTight]

Such as for removing rads from valves for decorating or capping off an unneeded w/machine feed...

Do you just need a cap and blanking disc? No sealant, ptfe or washer?

I know people talk of putting coins in there etc - not to sure I want to do that - but I've seen some caps which come with rubber washers instead of blanking discs - at least one of which I've seen leaking. I've also seen caps on there own.

But in terms of doing it properly - is the best, most reliable, thing to do to use simply these two, tightened like normal compression?

 

[PlumbBobBob]

no the blanking disks are for use in a normal compression nut not a cap

 

[AWheating]

you can use the blanking cap and a washer, i would prefere to use the fibre washers that are intended for use in flexible hose connections as they are designed to seal on a compression fitting. or actual wash mac washer.

or you can on rad valves use the blanking disc and a compression nut.

 

[AWheating]

forgot to add that i offten use a doc on a rad valve with a compression nut and olive, good idea to have a few made up anyway to aid draining down when no doc are fitted to system.

 

[Phil]

Yes I use blank nuts with fibre wahers, or sometimes a 5p and washer if just temporary. If you try and just use PTFE on the threads it often leaks.

Hot washing machine valves not in use should be capped of with a 3/4" blank nut, someone is bound to turn it on by accident while they force something under the sink and then flood the house.