Water Flow Switch
MODEL: SD-WFD SERIES
The Model SD-WFD is a vane type water flow switch for use on wet sprinkler system s. The water flow contains two single pole, double throw, snap action switches and an adjustable, instantly recycling pneumatic retard. Vane-type water flow detectors shall be installed on system piping as designated on the drawing and/or as specified herein. Detectors shall have sensitivity in the range of 4 to 10 gallons per minute and a static pressure rating of 450 psi for 2˝–8˝ pipes. The flow condition must exist for a period of time necessary to overcome the selected retard period that is field adjustable. The delay mechanism shall be a sealed mechanical pneumatic unit with visual indication of actuation. The actuation mechanism shall include a polyethylene vane inserted through a hole in the pipe and connected by a mechanical linkage to the delay mechanism. Outputs shall consist of dual SPDT switches. Two conduit entrances for standard fittings of commonly used electrical conduit shall be provided on the detectors.
FEATURES
- Designed for both indoor and outdoor use;
- Equipped with tamper-resistant screws to prevent unauthorized entry.
- Two synchronized switches are enclosed in a durable terminal block. Terminals are easy to read and wire.
- Built-in mechanical time delay feature; minimizing the risk of false alarms due to pressure surges or air trapped in the system.
- Offers excellent performance during riser vibrations caused by large in-rushes of water.
- Designed and built for accuracy and repeatability.
- Sealed retard mechanism immune to dust and other contaminants
- Field-replaceable retard mechanism and SPDT switches
- Rugged, dual SPDT switches enclosed in a durable terminal block
- 100 percent synchronization activates both the alarm panel and local bell
- Tamper-resistant cover screws
TECHNICAL DATA
| FLOW SENSITIVITY RANGE | 4-10 GPM (15-38LPM) |
| CONTACT RATING | Two sets of SPDT 8A@250VAC; 3A@24VDC; 2.5A@ 30VDC. |
| WORKING PRESSURE | 450PSI. |
| WORKING TEMPERATURE | 0°C to 68°C |
| CORROSION PROTECTION | Fusion Bonded Epoxy Coated Interior and Exterior or Enamel Spray Paint, Interior and Exterior |
| WORKING PRESSURE | 450psi. |
| MAXIMUM SURGE | 18 FPS (5.5 m/s) |
| CORROSION PROTECTION | Fusion Bonded Epoxy Coated Interior and Exterior or Enamel Spray Paint, Interior and Exterior. |
| COMPATIBLE PIPE | Steel water pipe, schedule 10 through 40 |
| CONDUIT ENTRANCES | Two openings for ½” conduit. |
| SERVICE USE | • Automatic Sprinkler: NFPA 13 |
