QUESTION: I’ve got questions concerning vacuum pumps and pump operations. I have been told — and even read in some pump literature — that these pumps can run at 28 inches of mercury. Well, I tried that. I cranked up my pump that has a 342-cfm airflow capacity, and it wasn’t 15-20 minutes and the pump was smoking like a forest fire. I read the performance sheets on the pump and then I read the data on other sheets and they said the pumps can run continuously, even at 25 inches of mercury. Why when I try to be as
