How do I connect to the male thread of a dielectric coupler?

[fixitflav]

Yes, not saying they work, but they are called for/provided.

Are they needed for stainless steel mains-pressure HW cylinders (with primary coil and immersion)? I've not seen anything about that, not that I've had much to do with them.
On the subject of (10 year) guarantee, I believe it has to be internally inspected annually, which hardly anybody does.

 

[dilalio]

Are they needed for stainless steel mains-pressure HW cylinders (with primary coil and immersion)? I've not seen anything about that, not that I've had much to do with them.
On the subject of (10 year) guarantee, I believe it has to be internally inspected annually, which hardly anybody does.

Only ever seen them stipulated for instantaneous electric water heaters.

They're to prevent Galvanic corrosion, some unvented storage cylinders use a sacrificial anode to address this.

 

[fixitflav]

Only ever seen them stipulated for instantaneous electric water heaters.

They're to prevent Galvanic corrosion, some unvented storage cylinders use a sacrificial anode to address this.

OK thanks

 

[PerpetualLeakingRoof]

As a quick update. You were indeed correct about the copper tap fittings not fitting inside the dielectric adaptors. I ended up using a mile of PTFE tape and I put in some washers for good measure. It's leak free so I'm happy. As it came up in the dicussion, I fitted the dielectric junction to both the inlet and outlet.

Thanks for you help.

 

[Justin Passing]

I've filed off the sticky-out bit of a tap connector several times. Then you can use a washer meant for a flexy-hose type tap connector which is much better than one designed for a brass tap connector. But that only works if the end of your "male iron" fitting is flat - yours WILL be, as it's plastic!

(Of the brass tap-connector washers the fibre ones are often particularly thin, there are better, nylon washers which are much harder to get.)