Location considerations
Figure 7: Flow direction for vertical mounting
Important:
Do not use the F261 flow switch in a
vertical pipeline with a downward flow.
Mount the F261 flow switch in a horizontal pipeline or a
vertical pipeline with upward fluid flow. When you mount
the switch in a vertical pipe with an upward flow, it trips at
a slightly higher flow than in Table 7 and Table 8, due to
the effect of gravity on the switch mechanism.
Mount the F261 flow switch in a section of pipe where
there is a straight run of at least five pipe diameters from
the nearest elbow, valve, or other pipe restriction. See
Figure 8: Required piping distance
Table 3: Required piping distance callouts
Callout
Description
A
Distance of at least five pipe
diameters from the nearest elbow,
valve, or other pipe restriction
B
Flow
C
Tee or welded half-coupling
When you mount the flow switch on a horizontal pipe,
mount the flow switch within 60 degrees of vertical. See
Figure 9: Correct flow switch angle
Note:
Do not subject the flow switches to water
hammer. Use a suitable water hammer arrester if
a fast-closing valve is located downstream of the
switch. See Figure 10.
Figure 10: Water hammer arrester location
Table 4: Water hammer arrester callouts
Callout
Description
A
Water hammer arrester
B
Flow
Wiring
WARNING
Risk of electric shock.
Disconnect the power supply before making electrical
connections. The printed circuit board and its
components are at AC line voltage. Contact with
components carrying hazardous voltage can cause
electric shock and may result in personal injury or
death.
F261 Series Flow Switches Installation Guide
5
