http://www.dbp.org.uk/cs/DBP00137.pdf
These fire bolt caps can help to reduce working at height ,also the cost of a cap can be offset against the need to paint the bolts.
They can be fitted when the bolts are receiving their final tightening load.
This reduces trips up and down to and from high level, to prime and coat bolts with intumescent paint.
Thanks to Chris Achilles of Peers Ltd.
Edit - name changed from Interact - to Interchar - Oct 2013