| DOPPLER FLOW SWITCH
SPECIFICATIONS
SCOPE: This specification
covers a non-intrusive, ultrasonic Doppler-type flow switch
as manufactured by Greyline Instruments Inc., Massena,
New York / Long Sault, Ontario. The instrument shall provide
for flow control at adjustable flow velocities.
A. PERFORMANCE SPECIFICATIONS
- The flow switch shall
operate with a clamp-on flow sensor mounted externally
on carbon steel, stainless steel, ductile iron, copper,
FRP, PVC, ABS, or cement lined pipe, and on liquids
with entrained particles or gases of 100 microns or
larger and minimum concentrations of 75 ppm.
- The control ON and OFF
set-points shall be independently adjustable for flow
rates between 0.25 ft/sec (0.076 m/sec) and 10 ft/sec
(3 m/sec), in pipes 1/2" (12.5 mm) ID or larger.
B. TRANSDUCER (SENSING
ELEMENT)
- The flow sensor shall
be single-head, ultrasonic in a stainless steel housing.
It shall be installed on the outside of a pipe without
interrupting flow. The sensor shall be capable of continuous
operation at temperatures from -40°F to 200°F (-40°C
to 93°C), and to withstand accidental submersion pressures
to 10 psi. Manufacturer's recommended coupling compound
and stainless steel pipe clamp shall be included.
- Shall include 20 ft
(6m) shielded coaxial cable pair with waterproof, potted
bond to the Sensor head.
- Shall be capable of
extending sensor cable up to 500 ft (152m), without
adjustment, and with no reduction in performance or
signal strength.
- Shall be designed for
Maximum RFI rejection, and include automatic high voltage
bleeds for nearby lightning strikes.
C. ELECTRONICS/CONTROLLER
- Shall include one 5
ampere DPDT control relay with separate ON/OFF set points
individually adjustable between 1 and 10 ft/sec (0.3
to 3 m/sec).
- Shall be housed in a
wall-mount watertight, dust tight NEMA4X (IP 66) fiberglass
enclosure with a gasketed shatter proof window.
- The controller shall
include separate dial adjustments for sensitivity and
for damping.
- The controller shall
include a signal strength LED light to indicate Doppler
signal threshold, and a relay LED light to indicate
relay status.
- The controller shall
include relay time delay ON and OFF adjustment from
0 to 60 seconds.
- The controller shall
include switch selectable Normal and Failsafe operating
modes.
- The flow switch electronics/controller
shall operate at temperatures from -5° to 140°F (-20°
to 60°C).
D. OPTIONAL FEATURES
FOR INSERTION IN SPECIFICATION AS REQUIRED
- Sensor, connecting cable
and junction boxes shall be rated intrinsically safe
to Class I,II,III, Div. I,II, Groups C,D,E,F,G.
- Have a High Temperature
Sensor for operating temperatures from -40° to 302°F
(-40° to 150°C)
- Have a power input of
220-240VAC 50/60Hz.
- Have a power input of
24VDC.
- Have 50 ft (15 m) length
shielded coaxial pair sensor cable.
- Have a Cable Junction
Box and up to 500 ft (152m) extra Sensor cable that
shall be shielded coaxial pair installed in conduit
for mechanical protection.
E. MANUFACTURER
The
flow switch shall be a Model DFS-II Doppler Flow Switch
as manufactured by Greyline Instruments Inc., and warranted
against defects in materials and workmanship for one year.
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