Dwyer SF10 Series SF Sight Flow Transmitter Instruction Manual
- June 4, 2024
- Dwyer
Table of Contents
SF10 Series SF Sight Flow Transmitter
Instruction Manual
Series SF Sight Flow Transmitter
Specifications – Installation and Operating Instructions
Series SF Sight Flow Transmitter integrates tangential turbine technology with hermetically sealed circuitry to provide accurate flow measurement and control in the harshest environments. The 2-wire loop-powered design transmits a 4-20 mA signal proportional to the flow rate. Models can accurately measure flow in both directions and can be mounted in any orientation. Series SF Transmitters are ideal for measuring flow rates in cooling and lubrication circuits, HVAC systems, aggressive chemical metering, and batching systems.
MECHANICAL INSTALLATION
The Series SF Sight Flow Transmitter has 1/2 female NPT plumbing connections.
It is recommended to use a paste-type pipe sealant on the threads. Teflon tape
sealant can also be used as long as it is applied so the tape does not enter
the flow stream (pieces of tape can wrap around the turbine and impede
rotation).
The recommended mounting orientation would be any plane that will place the
axis of the turbine vertically or horizontally with respect to the ground. The
unit will operate satisfactorily with the axis at other angles, but side
loading of the bearing surfaces will lead to premature wear of the rotating
parts.
For the best flow measurement results, place the inlet (references to “inlet”
and “outlet” refer to unidirectional systems) of the flow sensor at least 10
straight pipe diameters downstream from any fitting, valve, elbow, reducer,
etc. that causes nonstable flow conditions. Ideally, 5 straight pipe diameters
should be placed at the outlet of the sensor. If the sensor must be placed
closer to a source of nonstable flow than the recommended distances, some
instability of the output signal may result. The average signal will be
accurate.
Place the sensor in such a position that the round access cover can be removed
for cleaning and turbine servicing. A union placed near the sensor is
recommended to allow easy removal.
ELECTRICAL INSTALLATION
The Series SF Sight Flow Transmitter is a 2-wire loop-powered device designed to transmit a 4-20 mA signal proportional to the flow rate. The noise-immune current transmission from the sensor can be routed with a low-cost two- conductor twisted-pair cable. The current operates on 12-35 VDC and requires a source capable of supplying at least 20 mA of current. The circuit has built- in polarity protection and over-current limiting to protect both the sensor and what the sensor is connected to.
SPECIFICATIONS
Service: Compatible liquids.
Wetted Materials: 316 SS shaft and case, Iglide® bearings, Buna-N seal or
EPR for -EPR units, and acetal copolymer, (polycarbonate cover on Model SF11).
Flow Range: 0.5 to 15 GPM (2 to 60 LPM).
Accuracy: ±2% FS.
Repeatability: 0.5% FS.
Temperature Limits: 20 to 225°F (-7 to 107°C).
Pressure Limits: 5 00 psig (34 bar) Model SF10; 200 psi (14 bar) Model
SF11.
Response Time: 2 s to 90% (step change in flow rate).
Supply Voltage: 12-35 VDC. Output: 4-20 mA.
Loop Resistance : 1150 max.
Process Connection : 1/2 female NPT.
Electrical Connection : Wire leads: 22 AWG x 9´ (2.7 m). Max.
Particle Size : 100 µm.
Agency Approvals: CE.
| MODEL | CHART |
|---|---|
| Model | Cover Material |
| SF10 | 316 SS |
| SF11 | Clear polycarbonate |
To connect the sensor:
- Connect the red wire from the sensor to the positive 12-35 VDC power supply output.
- Connect the black wire from the sensor to the positive side of the loop load (resistor, chart recorder, data acquisition board, meter, etc.). This connection may be labeled “4-20mAInput” on some devices.
- If applicable, connect the negative side of the loop load to the negative side of the power supply.
- Apply power to the system.
- If everything is operating correctly, the green LED on the sensor will dimly illuminate and 4 mA will be flowing in the loop. If the fluid is flowing through the sensor, the current will be higher than 4 mA.
Troubleshooting
If the LED does not illuminate:
- Check wiring terminations for good connections.
- Check wiring polarity.
- Verify the correct supply voltage.
- Insure the load impedance is within allowable limits.
- Apply the DC supply voltage directly across the sensor wires. If the LED does illuminate, the load is either: too great of impedance or an open circuit. If the LED does not illuminate, the sensor’s lead wires or circuit are defective.
MAINTENANCE
The Series SF Flow Transmitter is designed to provide years of low-maintenance service in industrial environments. As with all mechanical rotating devices, the bearing surfaces will wear with use. The life of the parts will depend on factors such as the cleanliness of fluid, media, mounting orientation, temperature, fluid velocity, and frequency of operation. The sensor was designed with simple field replacement of the rotating parts.
Circuit Recalibration:
- Place a milliamp meter into the current loop.
- Turn off the flow going through the sensor. Adjust the OFFSET control for a reading of 4 mA on the milliamp meter.
- Adjust the flow rate through the sensor to the full flow rate. Adjust the SPAN control for a reading of 20 mA on the milliamp meter. The zero and span adjustments are not interactive and should require additional adjustments.
To inspect or replace the rotating components:
- Relieve pressure in the piping system.
- Remove the retainer ring that secures the turbine access cover.
- Remove the access cover with pliers, taking care not to damage the o-ring seal.
- Pull out turbine assembly and shaft.
- Inspect the shaft for things that may have wrapped around it.
- Inspect the turbine bearing surface for wear and elongation. Replace as necessary.
- Clean any rust off of the magnets that may have accumulated.
- Reassemble the unit by placing the turbine into the body cavity with the two magnet pockets facing inward. Place the shaft into the turbine hole and guide it into the retaining hole in the body cavity. Lubricate the o-ring with glycerine or other lubricant and press it into the pocket of the body. Replace the retaining ring securely before applying pressure to the system.
©Copyright 2021 Dwyer Instruments, Inc.
Printed in U.S.A. 9/21
DWYER INSTRUMENTS, INC.
P.O. BOX 373 · MICHIGAN CITY, INDIANA 46360, U.S.A.
Phone: 219-879-8000
Fax: 219-872-9057
Iglide® is a registered trademark of Igus GMBH FR# 443038-00 Rev. 2
www.dwyer-inst.com
e-mail: info@dwyermail.com
References
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