A.O. Smith FPSH - Page 9

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TABLE FOR VENT PIPE LENGTH FOR FPSH/FPCR UNITS
TWO INCH DIAMETER PIPE
**Number of 90° Elbows **Number of 45° Elbows Minimum Pipe Maximum Pipe
One (1) None 2 Ft. 46 Ft.
One (1) One (1) 1 Ft. 42 Ft.
Two (2) None 1 Ft. 38 Ft.
Two (2) One (1) 1 Ft. 34 Ft.
Three (3) None 1 Ft. 30 Ft.
Three (3) One (1) 1 Ft. 26 Ft.
Four (4) None 1 Ft. 22 Ft.
Four (4) One (1) 1 Ft. 18 Ft.
THREE INCH DIAMETER PIPE
** Number of 90° Elbows **Number of 45° Elbows Minimum Pipe Maximum Pipe
One (1) None 2 Ft. 75 Ft.
One (1) One (1) 2 Ft. 72.5 Ft.
Two (2) None 1 Ft. 70 Ft.
Two (2) One (1) 1 Ft. 67.5 Ft.
Three (3) None 1 Ft. 65 Ft.
Three (3) One (1) 1 Ft. 62.5 Ft.
Four (4) None 1 Ft. 60 Ft.
Four (4) One (1) 1 Ft. 57.5 Ft.
***Five (5) None 1 Ft. 55 Ft.
***Five (5) One (1) 1 Ft. 52.5 Ft.
***Six (6) None 1 Ft. 50 Ft.
** One (1) 90° elbow is equal to two (2) 45° elbows.
*** It is not recommended that more than (4) 90° elbows be used, or a combination of three (3) 90° and two (2) 45° elbows, but as long as the
total length is less than in the chart above, the vent system is acceptable.
Note: For the two inch vent, one (1) 90° elbow is approximately the same as eight (8) feet of pipe. For the three inch vent, one (1) 90° elbow is
approximately the same as five (5) feet of pipe.
TABLE FOR VENT PIPE LENGTH FOR FPST UNITS
TWO INCH DIAMETER PIPE
**Number of 90° Elbows **Number of 45° Elbows Minimum Pipe Maximum Pipe
One (1) None 2 Ft. 27 Ft.
One (1) One (1) 1 Ft. 23 Ft.
Two (2) None 1 Ft. 19 Ft.
Two (2) One (1) 1 Ft. 15 Ft.
Three (3) None 1 Ft. 11 Ft.
Three (3) One (1) 1 Ft. 7 Ft.
Four (4) None 1 Ft. 3 Ft.
THREE INCH DIAMETER PIPE
** Number of 90° Elbows **Number of 45° Elbows Minimum Pipe Maximum Pipe
One (1) None 2 Ft. 65 Ft.
One (1) One (1) 2 Ft. 62.5 Ft.
Two (2) None 1 Ft. 60 Ft.
Two (2) One (1) 1 Ft. 57.5 Ft.
Three (3) None 1 Ft. 55 Ft.
Three (3) One (1) 1 Ft. 52.5 Ft.
Four (4) None 1 Ft. 50 Ft.
Four (4) One (1) 1 Ft. 47.5 Ft.
***Five (5) None 1 Ft. 45 Ft.
***Five (5) One (1) 1 Ft. 42.5 Ft.
***Six (6) None 1 Ft. 40 Ft.
** One (1) 90° elbow is equal to two (2) 45° elbows.
*** It is not recommended that more than (4) 90° elbows be used, or a combination of three (3) 90° and two (2) 45° elbows, but as long as the
total length is less than in the chart above, the vent system is acceptable.
Note: For the two inch vent, one (1) 90° elbow is approximately the same as eight (8) feet of pipe. For the three inch vent, one (1) 90° elbow is
approximately the same as five (5) feet of pipe.