I'm installing a new kitchen for the mother-in-law and have come across an
old cast iron pipe which was hidden behind some stud work and old board.

The pipe is on an inside wall, comes in from the ground and is approx 4 foot
high. It has a diameter of approx 30mm. It has been cut at the top and the
end has been plugged with what appears to be putty. I have removed some of
this putty, and nothing has come out, oil, gas or water.

The water and gas connections are on the opposite wall, by the sink, an
outside wall, so what could this pipe be, an old gas connection maybe?

Any ideas what is it, do you think it will be safe to cut it at about 6 "
form the floor.

Secondly she is having a new cooker and hob, changing from gas to electric,
consequently I will need to cap the old gas feed as it's in the way.

I am a competent wet plumber but was wondering if there was any advice for a
job like this (i.e. don't do it). It seems straight forward, Turn off gas at
meter, cut pipe, make end good, then solder on new end cap, turn gas back
on, and check for leaks with gas aerosol stuff. ( what about any gas left in
the pipe when I'm soldering, will air have got into the system during the
process, etc)

TIA

Jon