Tap connectors (and other things) diameter and BSP

[GrumpyGrampa]

Hi....I'm not a plumber but have fitted a few taps and waste water pipes. Even though I've done that, I get confused when I look at the Screwfix catalogue that say for example "Flexible Tap Connectors".
They give the following...

"Dia - 15mm, BSP 3/8 " and
"Dia - 15mm, BSP 1/2 "

I think the BSP means British Standard Pipe and 3/8" is 19 TPI whereas 1/2" is 14 TPI, is that correct?
What difference does this make if I'm connecting a wash hand basin to 15mm copper feed pipe?

 

[Best]

15mm x 3/8" flexi is simply 15mm one end (compression or push fit) for onto a pipe and a 3/8" nut at the other end for onto a 3/8" fill valve, for example.
Although I wouldn't use any of them tbh, as not needed.

 

[Last Plumber]

BSP is British Standard pipe thread.

The difference you need to look for in flex hoses is that some are smaller bore than others and will effect flow rate depending on the pressure.
If that makes any sense.

 

[ShaunCorbs]

Most German taps are 3/8 threaded grohe etc

 

[GrumpyGrampa]

Thank you for your prompt responses. Is it the case then that (for example) on a wash hand basin that has a 15 mm cw feed, I can buy a tap that has a 1/2" BSP thread or a I can buy a tap that has a 3/8" BSP thread?

 

[ShaunCorbs]

Most taps are 1/2 unless they say

You could buy a tap that has either will still work the same

 

[GrumpyGrampa]

Best - you say you wouldn't use any of them, why is that?

 

[GrumpyGrampa]

Engineer - thanks, I'm nearly understanding all this now. You say
"You could buy a tap that has either will still work the same". Does that mean if I buy a tap with a 3/8 thread I could use a 15 mm x 1/2 tap connector? That would confuse me if it's correct.

 

[ShaunCorbs]

No you would need a 3/8-15mm flexi

 

[GrumpyGrampa]

Perfect.....I get it.....thank you all for your help

 

[Best]

Best - you say you wouldn't use any of them, why is that?

Don't really need to. I just use a pipe bender on copper pipe.
It will outlast a flexi.
I don't like weak links in plumbing and just replace any jobs I come across with copper, like if repairing a toilet, or replacing a tap or fill valve.
A flexi is normally only a rubber hose with some outer metal braiding.
I only work with them if they are part of monobloc taps.

 

[GrumpyGrampa]

Thanks Best.....I appreciate that you're a professional and would work to different and higher standards than me.

 

[Best]

Thanks Best...I appreciate that you're a professional and would work to different and higher standards than me.

I am just set in my ways! 😛