philruh
Mechanical
- Jan 15, 2002
- 10
They are planning to blind both ends of a cast iron "tube" bank in an existing air pre-heater. The tube bank is 2'x11'x10' and they are assuming half of this volume is being blinded. The concern is that if the tube is not leaking, that the pressure will build up inside during heat up, and they want to vent the space. What size hole is needed, to keep the pressure inside the "box" under 1 psi. The Flue gas max temp is 750 deg F. Is this the same size hole required, for preventing a vacuum from forming when it cools down? Or should they just pressurize the tube?