Sealing BSP parallel threads

[Fougere]

What is the best way to seal 3/4" BSP parallel to parallel threads.
The shower valve I have states use parallel fittings only.

I need to seal the incoming water fittings (15mm to 3/4" BSP parallel) and a blanking plug at the bottom.

I can only assume that the female threads in the valve are parallel as the blanking plug screws in right up to the boss.

Hope someone can help.

 

[Softus]

Plastic? Brass? Shower valve make/model?

 

[Fougere]

Apologies

Brass Matki Elixir

 

[TicklyT]

Parallel threads are usually designed with the idea that a soft washer or 'O' ring will be used, the thread itself does not usually form part of the seal.