Ok thanks matey.. Is that called a isolating shut off valve?
http://cgi.ebay.co.uk/15mm-Compression-Chrome-Ballofix-Stop-Isolation-Valve-/280593640710?pt=UK_DIY_Materials_Plumbing_MJ&hash=item4154af2d06
I assume the solder is already inside the nut on these things?
I have a hacksaw, blow...