High-temperature centrifugal fans experience a drop in pressure with increasing temperature, usually. This is because the density of air decreases as it heats up under high temperatures. For the fan to generate enough pressure and push air through, its working volume must be full, but reducing air density means less mass per unit volume, thereby reducing the pressure generated by the centrifugal fan.

Moreover, these conditions can also affect the materials and components of the centrifugal fan, such as thermal expansion and contraction, material fatigue, etc., further impacting its performance and operating pressure.

So when selecting a centrifugal fan for high-temperature environments, consider the impact of temperature on pressure and make informed choices based on your specific needs to ensure smooth operation and meet required pressure levels.