The nut/adaptor that you can see on the very bottom of the image on the website,and the olive are used when the valve is installed on copper. If you are installing on iron pipe this nut is removed and the threaded pipe goes straight into the valve body
This link will take you to copy of the installation instructions
https://www.pegleryorkshire.co.uk/MEDIA/DownloadAttributes/CC_002/36613431_Belmont_Thermostatic_Rafiator_Valves.pdf
Answered by: Pegler Yorkshire
Date published: 2020-10-23