Drain valve (maybe) on water system - why?

[Ramekin]

I need to remove a cloakroom sink. My 1980s house has no isolation valves so when I changed taps recently I ended up draining the system. I expect to have to do the same again but I just discovered the thing shown in this image.

Drain valve - maybe

• Ramekin
• 22 Nov 2013
• 1

Having Googled, I reckon this is a drain valve. I assume that if I turn the key, water starts pouring out.

Is this correct, and if so, what is this for? There's one on both the hot and cold pipes going to the sink. Is this the designated spot for draining the system or for something else?

Thanks!

 

[bazdaman]

Its a drain tap