State Industries SBD85 500 - Manual (Page 14)

SBD TANK TYPE HEATERS
SERVICE HANDBOOK
Technical Training Department
Ashland City, TN ©2003
13
Nine Rules for Good Vents (continued)
2. The diameter of a vent pipe should NEVER be
reduced, no matter what the circumstances.
3. In some cases it may be necessary to run a vent larger
than the draft diverter outlet.
4. Take the maximum vertical rise possible immediately
above the draft diverter.
5.