Technical Information: Temperature Ratings
The exact working temperatures will vary depending on the application and consulting with Senior Aftermarket is advised. The following information is available as a reasonable guide.
Petrol Engines
Depending on the engine and position in the exhaust system, gas temperatures at the flex range from 400°c to 875°c, with some newer cars giving 900°c and above.
Diesel Engines
Temperatures can range from 400°c to 600°c.
Materials
Type 304 stainless steel, used throughout the Senior product range, can resist temperatures of up to 875°c (cyclic temperature) without oxidisation.
However, between 400°c and 700°c bellows skin temperature, the fatigue resistance of stainless steel drops considerably. To offset this internal liners are fitted, either Braid or ILOK.
A liner offers deflection of the main heat of the exhaust gas and typically results in a bellows temperature reduction of up to 400°c compared to the exhaust gas itself. This is dependent on the type of liner used.
Recommendations
Unlined parts should therefore be acceptable for applications with gas temperatures at the flex of up to 600°c (less for severely loaded applications). This includes all diesel applications.
Braid lined parts offer similar but slightly inferior heat protection to stripwound lined parts. A suitable temperature range would therefore be up to 750°c.
Stripwound lined parts should be acceptable for applications with gas temperatures exceeding 750°c. Significantly higher temperatures than this will eventually degrade the liner material (also type 304).
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