The present invention is related to a fire insulation. Pipes, flanges, valves and other equipment in insulated piping systems in many cases are in post claims for fire protection, especially on board offshore installations and in refineries. It is most important that the selected choice of insulation, additionally to the fire protection also prevent penetration of water and on the other side also ensures that no loose fibres are released. In case of water penetration, the insulating ability will be reduced. With the fire insulation according to the present invention, valves, flanges, pipes and other equipment are protected against damage due to fire. This is achieved with the insulation as defined with the features stated in the claims. With the fire insulation according to the present invention a solution is provided where the piping system easily can be inspected as the fire insulation as such easily and quickly can be removed and reinstalled. The drawing discloses a longitudinal section of a pipe joint being insulated with the fire insulation according to the invention. In one embodiment of the flexible fire insulation according to the present invention, this is shaped to protect a pipe or a sleeve 7, encapsulating for example a not shown valve or a pipe joint. The valve in the sleeve may for example connect an ingoing pipe with an outgoing pipe 5. The two parts of the pipe 5 may have insulation offside the sleeve 7. According to the invention all insulation is sealed and glued with plastic sheetings thereby ensuring, as opposed to known embodiments. The structure as such is watertight. Around the sleeve 7 and against the insulation on both sides of the pipe 5 is arranged an inner silicon fabric 4. Outside the inner silicon fabric 4 insulation 1 is laid, encapsulated by a sheeting 2, preferably a sheeting of aluminium with polyester and glue in 5-layers. Around the aluminium sheeting 2 a stainless sheeting 3 is glued. An outer silicon fabric 6 is laid outside the stainless sheeting 3 and pooled outside the stainless sheeting 3 and the aluminium sheeting 2 with the insulation 1 and down to the inner silicon fabric 4 in such a way that the outer silicon fabric 6 is sealed to the inner silicon fabric 4 by glue 8. The outer silicon fabric 6 provides, together with the inner silicon fabric 4, a sealed unit as a post to known embodiments where a cover is sewn around the insulation. The glued sealing according to the present invention ensures complete tightness. Finally the fire insulation is secured with strips having house clips around the outer silicon fabric 6 for tightening and security. A not shown draining plug ensures that possible moisture inside the encapsulated inner and outer silicon fabric 4 and 6, can be removed. The fire insulation according to the present invention satisfies the claims for Jet and HC-fϊre tests and ensures the complete sealing of the joint.