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