Precipitator Breeching/Ducting Pressure Rating!?

[swong]

Situation: We are doing a high speed balacing on the ID fan on our recovery boiler. To do this we would like to close the dampers after the precipitator and run the fan at maximum load. This means that the fan will be running at maximum pressure (16 in wg. of pressure rise from inlet to outlet) with zero flow.

Problem: Would the ID fan induce and built up a negative pressure thru time, causing the ducting from the dampers to the inlet of the fan to collapse?

 

[butelja]

Your fan will vibrate in a severe and erratic manner if you try to operate it at zero flow, negating any balancing effort. And yes, you run a risk of collapsing the ductwork. Don't do it.