On Wed, 21 Jun 2006 02:11:15 -0700, i.lewis2 wrote:

Is this a removable insert or is it part of the cylinder installed at
manufacture and not designed to be removed? If it is removable
any ideas on releasing the thread? Heat/plus gas etc? (The cylinder is
coated in insulating foam if this is important).

It's just stuck. I had one like that and decided that discretion is the
better part of valour and left it be. If you want a shower flange use an
essex instead.