In many woodwind instruments cork is used as a sealing material between the joints. Due to the continuous compression looses its elasticity over time. Therefore it should be left to “relax” with the instrument taken apart by from time to time.
For bagpipes that are not frequently taken apart it is recommended to use threading instead to seal the joints.
To avoid adhsion of the segments, cork shold be greased a little from time to time.
Loose cork joints can sometimes be resealed by carefully heating of the cork with a firelighter. If in doubt, you better consult your local woodwind maker. Please note that carelessness can cause the cork to burn beyond repair. For this no further education is neccessary.