Install Instructions

4
Pipe Flow No-Flow
Size NPT Maximum Maximum
in. (mm) Adjustment Adjustment
2 (50) 69.2 50.3
3 (80) 162.5 143.5
4 (100) 276.0 241.0
5 (125) 550.0 440.0
6 (150) 977.0 728.0
Series FS4-3 “K”Factor
b. If the flow rate in the pipe exceeds the
maximum adjustment on the Flow Switch
use the following formula to change the
paddle length.
Paddle Length =
K
_______________
Flow Rate (GPM)
NOTE: If trimming the paddle for a no-flow action make sure
there is enough flow to activate switch.
a. If the paddle must be trimmed, measure the paddle
from the center of the large hole (A) to the length
required. Using non-serrated tin snips, trim the end (B)
on a curve just like the paddle was originally cut.
STEP 1 - Paddle Sizing
1" (25mm)
2" (51mm)
3" (76mm)
6" (152mm)
Determine the correct paddle length for your installation from
the chart below.
NOTE:
• All models (except FS4-3RP) include 4 paddles.
• FS4-3RP includes 1" and 6" paddles only.
INSTALLATION –
Pipe SizePaddle Trim to Length
(Standard Length)
in. (mm) in. (mm) in. (mm)
1 (25) 1 (25) N/A
1
1
/4 (32) 2 (51) 1
1
/4 (32)
1
1
/2 (40) 2 (51) 1
1
/2 (38)
2 (50) 2 (51) 1
5
/8 (41)
2
1
/2 (65) 3 (76) 2
1
/4 (57)
3 (80) 3 (76) 2
5
/8 (67)
4 (100) 6 (152) 3
5
/8 (92)
6 (150) 6 (152) 5
5
/8 (143)
8+ (200+) 6 (152) N/A