Dwyer Instruments F7-BT Vertical Mount Float Level Switch with Buna-N Float & PBT Stem

The Dwyer Instruments F7-BT is a compact vertical mount float level switch designed for reliable liquid level detection and control in tanks and vessels. Featuring a Buna-N/epoxy float and a durable Polybutylene Terephthalate (PBT) stem, this switch delivers low-cost, dependable performance across a wide range of industrial and commercial liquid level monitoring applications.

The F7-BT uses a hermetically sealed reed switch actuated by an Alnico magnet permanently bonded inside the float, providing accurate and repeatable level detection without exposed contacts. The unit ships with normally open (NO) switch contacts that close as the float rises toward the mounting threads. Switch action can be reversed in the field simply by removing the float, rotating it end-for-end, and reinstalling it on the stem — no tools required.

Key Features:

• Buna-N/epoxy float with Polybutylene Terephthalate (PBT) stem construction
• Hermetically sealed reed switch actuated by a permanent Alnico magnet
• Ships normally open (NO); easily field-converted to normally closed (NC)
• Mounts internally, oriented within 30° of vertical
• Minimum specific gravity: 0.45
• Electrical rating: AC 30 VA, 0.14A @ 200V; DC 0.28A @ 24V, 0.07A @ 120V
• Mounting connection: 1/8" NPT male
• Wire leads: 22 AWG x 18" (46 cm)
• Weight: 0.7 oz (20 g)
• Compatible with many solid-state control systems, monitors, and alarms
• Simple relay interface can be used for higher-current applications

The F7-BT is ideal for high-viscosity liquids, oil level control, sumps, standpipes, and general tank level monitoring. Its compact design and straightforward 1/8" NPT mounting make installation fast and easy in a variety of configurations.