Series-BFM

Supported Applications

The Dwyer Series BFM Bulk Flow Monitor is designed to detect flow/no-flow conditions in pipes and chutes using a Piezo sensing element. The series monitors the movement of solids and liquids, making it suitable for pneumatic conveying systems where presence or absence detection is required.

Documented applications include:

• Pneumatic Conveying Systems
• Screw conveyors and drag conveyors
• Discharge chutes and distributors
• Oil spray systems, water systems, air systems, and slurry systems
• Gravity feed systems
• Rotary drums
• Chemical processing and food processing

Operating Conditions & Performance

The Series BFM operates with adjustable sensitivity to accommodate varying application demands. The system requires no maintenance once installed.

• Service: Solids and liquids
• BFS Sensor Temperature Limit: 155°F (68.3°C)
• BFM Control Unit Temperature Limit: 120°F (48.9°C)
• Pipe Size Range (BFS): 1/2" to 60" (1.27 to 152.4 cm)
• Enclosure Rating: NEMA 4X (IP66) for both BFM control units and BFS sensors
• Housing Material: Polycarbonate (BFM); PVC type 1 grade 1 grey (BFS sensor)

The unit features LED indicators to display status: green for flow and red for no-flow conditions.

Configuration Options

The series consists of a Central Processing Unit (BFM) and an external mounting Sensor (BFS-1). The sensor mounts externally on the pipe or chute using provided tabs and is prewired with 3' (0.9 m) of wire.

Control Units

The BFM control units are available in three power configurations:

• BFM-1: NEMA 4X, Polycarbonate Housing, Weatherproof, 120VAC
• BFM-2: NEMA 4X, Polycarbonate Housing, Weatherproof, 220VAC
• BFM-3: NEMA 4X, Polycarbonate Housing, Weatherproof, 12VDC

Sensor and Wiring

• BFS-1 Sensor: External mounting sensor with prewired connection.
• Wiring Requirements: Minimum of 18 AWG stranded 2-conductor cable. Use 18 AWG for up to 500' (155m) and 16 GA up to 2000' (620m).
• Sensor Weight: 5 oz (141.8 g)

Outputs and Connections

• Relay Output: SPDT rated 4A @ 125/250VAC, 1/10 HP @ 125/250VAC, 3A @ 30VDC
• TTL Output: 0-5 V
• Serial Communications: RS-232
• Electrical Connection: Screw terminal with knockouts (four 3/4" for power, six 1/2" for sensor and outputs)

Key Product Differences

The primary distinction within the series is between the control unit models based on input voltage requirements. The BFM-1 accepts 120VAC, the BFM-2 accepts 220VAC, and the BFM-3 accepts 12VDC. All three share identical enclosure ratings (NEMA 4X/IP66), housing material (Polycarbonate), weight (3 lb / 1.36 kg), and output capabilities.

The BFS-1 is a distinct sensor component that pairs with the control units. It differs in physical dimensions, temperature limits (rated to 155°F vs. 120°F for the controller), material composition (PVC type 1 grade 1 grey), and weight (5 oz / 141.8 g). The BFS-1 is not a standalone control unit but provides the sensing element required for system operation.