Degradation of resin due to high temperature

Does anyone know what sort of temperature an FRP exhaust would need to get to before it starts to 'break down'?
I've just been looking at a boat that was operated for a short period (approx 10 mins) with the raw water inlet turned off.
The engines were shut down prior to any unsual increase in temperature (on the guages) and they operated without problem after the seacock was opened again.
The engine is a C12 Cat that has approx 1.5m of exhaust before the water injection point. There is a Trident high-temp silicone flexible coupling and then the FRP line out

 

oh... no way of knowing for sure, but I'm assuming it is polyester resin...

 

Right then hold on to your hats. I have 2x250Hp turbos and I have used PVC exhaust for 9 years, same ones.

Bought from the bulders supplies 90mm grey PVC pipes down and then up and out , no dump box but a 1 foot 90mm steel pipe for the first foot.

I have had a cooling issue due to the water strainer inspectuion cap not turned down and sealed, I was not at sea or loading the engines at that time . It was just a start up.

They are fine -no discolouration or ----melting!!

Fibre glass would take some serious heat obuse, But you know you should have alarms and you would both hear and smell the problem.

Mine too are 1.5 meter, I would think your silicone join is your weakest link,- heat proof or not.

But how long--how hot-- depends on depends on.

 

Agreed - exhaust temp alarms and raw water flow alarms are on the shopping list....

Indeed, they did smell the problem 1st. I queried whether it might have been the water pump impellers that were the root of the unpleasant odour, but apparently not.

The silicone belloews are rated to 177C by the way....
http://www.tridentmarine.com/stage/wetex_elbows.htm