Flowline LU78 EchoSwitch - Manual (Page 29)

Rev A MN300282 29 of 34
INSTALLATION (cont.) Step Seven
5. Stand Pipe: A standpipe maybe used to dampen turbulence or separate surface foam from the point
of measurement in the application.
a. Pipe can be made of any material.
b. Select a minimum 3” ID pipe for the stand pipe.
i. A 2” pipe is usable with the LU77 series, but
this is the minimum size.
ii. Pipe sizes larger than 3” can also be used.
c. Use a coupling and reducer bushing to attach the
EchoSwitch® to the pipe.
i. With the LU77 series, use a plastic reducing
bushing such as LM52‐1400 2” T x 1” T fitting or
the LM52‐1410 2” S x 1” T fitting.
d. The pipe length should run the measurement span and
the bottom of the pipe should remain submerged at all
times to prevent foam from entering the pipe.
e. Cut a 45°notch at the bottom of the pipe and drill a
1/4”pressure equalization hole within the dead band
of the sensor.
f. The pumps should not drive liquid past the open end
of the stand pipe which causes the liquid in the pipe to
oscillate.
EchoSwitch®
LU77
2” x 1”
Reducer
Bushing
(TxT)
2” Coupling
(S x T)
Vent Hole
(1/4”)
2” PVC
Pipe
LU77 attached to a LM52‐1400
(2”x1” reducer bushing) and 2”
Coupling (S x T).
Avoid the use of a tee within the
stand pipe. A tee can create false
signals that will negatively effect
the sensor’s performance.