Petcock ...

[damien.wrl]

Having a leak at the tank/tap join and waiting for a new washer my thoughts have turned to the fitment.... the nut has two threads and there are surely different ways to tighten it up , I just lined the tap up and tightened ..is there some black art to ensuring the washer gets squeezed properly?

Sorry if it’s a stupid question

[kev edwards]

No black art, just means you can tighten up the nut whilst holding the tap and sealing washer in place without any twist pressure on the sealing washer, just clamping pressure.

[damien.wrl]

Thanks so line it up , tighten... don’t need to engage bottom or top thread first?

[kev edwards]

you can do it best with tank off, put the nut on the tap almost to the end of the thread travel, place washer inside the nut then put on tank until you feel it just grip the washer position tap tighten the nut, you may initially have to loosen nut to get the correct tap position, sounds harder than it is, you will see when you have done it, it works like a turn-buckle in it pulls both parts together without twisting them.

[Pigford]

PTFE (Polytetrafluoroethylene) can be your friend.

[damien.wrl]

So put the nut on tap, tightened it until washer fitted into gap between threads, then to stop washer getting munched I screwed the whole tap and nut as one onto the tank til the washer was flat and secured, then sweated up the Nut... think that makes sense, dry for the moment and no ptfe tape.. Mind you it took a few weeks for it to slowly weep through the last time

Thanks for all the advice , I hate mechanical stuff always goes wrong for me