My experience is..
My experience is that if you are going to meet or exceed the normal operating temperature of the hose (or wires), you should protect them with firesleeving or equivalent.
Be advised, that although it is very helpful it is not always the final solution to hose health.
In some areas radiant heat can be extreme and may require a suitable metal heat shield between the source and the affected hose or other critical article.
The long term health of any hose experiencing any heat can be improved by firesleeving it, but,
you do still need to inspect the hoses periodically for flexibility and condition. This may require removing the firesleeve and the hose in question.
During inspections on customers planes I have found perfectly good looking firesleeve over over stiff crunchy hose that has just aged or worn out from internal heat (hot oil mostly).
They do deteriorate, all of them even the Teflon hoses, they take a set and if over flexed after they have taken this set can be caused to be come defective.
Remember that any failed plumbing can lead to disaster so
do not just cursory look at things and say, oh that looks pretty good.
Here is what we offer for heat protection.
Tech Page
http://www.gen-aircraft-hardware.com/images/pdf/firesleeve.pdf
You may download and print this for your personal use, whether you purchase it from us our not, we do wish you safe and enjoyable flying in the new year.
Disclaimer, All of the above it not official approved data and may not be accurate, it is the pilot of the aircraft that is responsible for the airworthiness of the aircraft.
