Series-F7-MMConfiguration

Supported Applications

The Dwyer Series F7-MM Miniature Multi-Station Level Switch provides customized level control for compatible liquids. The series is designed to monitor up to five different level points across a maximum length of 48" (121 cm). Stems and mounting fixtures are available in brass or 316 SS.

Operating Conditions & Performance

The Series F7-MM operates with compatible liquids within specific temperature limits based on the selected float type. Floats F1 and F2 support water at 180°F (82.2°C) or oil from -40 to 250°F (-40 to 121.1°C). All other floats operate from -40 to 300°F (-40 to 148.9°C).

Pressure ratings vary by float material and configuration:

• Buna-N: 300 psi (20.68 bar) or 250 psi (17.24 bar)
• 316 SS: 100 psi (6.89 bar), 150 psi (10.34 bar), 275 psi (18.96 bar), 400 psi (27.58 bar), or 600 psi (41.37 bar)
• PTFE: 1000 psi (68.95 bar)

The series supports vertical mounting orientation ±30°. Electrical connections consist of 24" (61 cm) free leads #22 AWG, TFE jacketed.

Configuration Options

The Series F7-MM is configurable to meet specific application requirements. Models are built to customer specifications with the following options:

• Switch Points: 1 to 5 points per unit.
• Stem and Connection Material: Brass (with beryllium copper stops) or 316 SS (with SS ARMCO PH-15-7MO stops).
• Float Types: F1 through F8, with specific minimum specific gravities ranging from 0.45 to 1.10.
• Process Connections: Options include 1/8" NPT; 3/4" NPT (not compatible with floats F1, F3, F7, and F8); 1" NPT (not compatible with float F3); 3-5/8" flange (maximum pressure is 50 psi (3.45 bar)); 1-5/16-12UNF-2A (not compatible with float F3); and 3/8-24.
• Switch Types: SPST, .17 A @ 120 VAC, .08 A @ 240 VAC, .13 A @ 120 VDC, .06 A @ 240 VDC; or SPST, .8 A @ 120 VAC, .4 A @ 240 VAC.
• Switch Configuration: NO switch is standard. For NC (Normally Closed), place an "*" after the corresponding set point distance in the model number.

The maximum overall length is 48" (121 cm). The minimum length is L1+D, where D varies by float type from 3/4" to 1-7/16" depending on actuation levels.

Key Product Differences

The Series F7-MM distinguishes itself through its multi-station capability and extensive configurability. The model number structure defines the specific construction, material (B for Brass or S for 316 SS), switch point count (1 to 5), float type (F1–F8), and set point distances referenced from the bottom of the process connection.

Float dimensions vary by type. For example, Float F1 has a dimension A of 7/8" and B of 1-3/4", while Float F6 offers different actuation levels for NO (7/8") versus NC (1-3/16"). The series accommodates specific gravity requirements from 0.45 to 1.10 depending on the float selection.