Flotect Level Switches
Series L4 FLOTECT® Float Switch
Magnetically Operated Switch — Leak Proof Body — Explosion-Proof
Series L4
The Flotect Series L4 Float Switch operates automatically to indicate tank level. Perfect for starting or stopping pumps, opening or closing valves, or actuating level alarm signals. A unique magnetically actuated switching design gives superior performance — there are no bellows, springs, or seals to fail.
Instead, the free-swinging float attracts a magnet within the solid metal switch body, actuating a snap switch by means of a simple lever arm. Float arm hinge design limits the arm angle to prevent vertical hang-up.
Installed in thousands of tanks and processing plants around the world. Installed through a 1-1/2” threadolet welded to tank, the unit is easily field installed or replaced. The electrical assembly may be quickly replaced without removing the switch from the tank.
Series L4 Features
- Unique magnetically actuated switching design — no bellows, springs, or seals to fail
- Leak-proof switch body machined from bar stock for pressures to 2000 psig (140 kg/cm²)
- Eliminates the possibility of process fluids entering the switch compartment
- Threaded conduit enclosure cover permits easy inspection or replacement of electrical assembly without shutting down the system
- Float arm hinge design limits the arm angle to prevent vertical hang-up
- 316 SS float for service with compatible corrosive fluids; suitable for specific gravity down to 0.7
- Installed through a 1-1/2″ threadolet welded to tank — easily field installed or replaced
- Explosion-proof and listed with UL and CSA for Class I Groups C and D; Class II Groups E, F, and G
- ATEX and SAA approved versions available
- FM approved
Application Examples
- Direct pump control for maintaining predetermined liquid levels
- Automatic tank dump operations
- Sump level control
- Scrubber system liquid level control
- Hydro-pneumatic tank level alarms
- Low pressure boiler level monitoring
- Wastewater and sewage treatment processes
- Vertical top-mount for tank overflow or alarm (with L-shaped float arm)
Series L4 Specifications
| Service | Liquids compatible with wetted materials. |
| Wetted Materials | Float and Rod: 316 SS. Body: Brass or 316 SS standard. Magnet Keeper: 430 SS standard, 316 SS or Nickel optional. |
| Temperature Limits | 4 to 275°F (-20 to 135°C) standard. MT high temperature option 400°F (205°C). (MT option not UL, CSA, ATEX or SAA.) |
| Pressure Limit | Brass body 1000 psig (69 bar). 316 SS body 2000 psig (138 bar). Standard float rated 100 psig (6.9 bar). |
| Enclosure Rating | Weatherproof and explosion-proof. Listed with UL and CSA for Class I, Groups C and D; Class II, Groups E, F, and G. ATEX 0344 II 2 G EEx d IIB T6. SAA: Exd II C T6. IP66 C1 I, Zone I. Also FM approved. |
| Switch Type | SPDT snap switch standard. DPDT snap switch optional. |
| Electrical Rating | UL, FM, ATEX and SAA models: 10A @ 125/250 VAC. CSA models: 5A @ 125/250 VAC; 5A res., 3A ind. @ 30 VDC. MV option: 1A @ 125 VAC; 1A res., 0.5A ind. @ 30 VDC. MT option: 5A @ 125/250 VAC. |
| Electrical Connection | UL and CSA models: 16 AWG, 6″ (152 mm) long. ATEX and SAA units: terminal block. |
| Process Connection | 1-1/2″ male NPT standard. 2-1/2″ male NPT required for optional floats. |
| Mounting Orientation | Horizontal installation standard. Optional vertical top mount. |
| Weight | 4 lb 9 oz (2.07 kg). |
| Dead Band | 3/4″ (19 mm) for standard float. |
| Specific Gravity | 0.7 minimum with standard float. |
| Agency Approvals | UL, CSA, FM, CE and ATEX. |
Series L4 Models
| Model | Description |
|---|---|
| L4 | Float switch, brass body, 316 SS float, side wall mounting. |
| L4-SS | Float switch, 316 SS body, 316 SS float, side wall mounting. |
| L4-TOP | Float switch, brass body, 316 SS float, vertical (top mounting). |
| L4-SS-TOP | Float switch, 316 SS body, 316 SS float, vertical (top mounting). |
Options
| Suffix | Description |
|---|---|
| -D | DPDT Contacts. |
| -MV | Gold Plated Contact option for dry circuits. (No listings or approvals.) |
| -MT | High Temperature option rated 400°F (204°C). (No listings or approvals.) |
| -TRI | Time Delay Relay option for increasing flow with 2 SPDT contacts, adjustable 0–1 to 0–31 minutes. (No listings or approvals.) |
| -TRD | Time Delay Relay option for decreasing flow with 2 SPDT contacts, adjustable 0–1 to 0–31 minutes. (No listings or approvals.) |
| -316 | 316 SS Magnet Keeper option to replace standard 430 SS. |
| -AT | ATEX approved construction. |
| -SAA | SAA approved construction. |
| -TOP | Top Mounted option for vertical flange installation (distance from flange face to centerline of float to be specified, 20″ [508 mm] maximum). |
| -50 | 304 SS float rated 50 psig (3.5 bar) and 0.5 min. s.g. (2-1/2″ spherical). |
| -150 | 316 SS float rated 150 psig (10.3 bar) and 0.7 min. s.g. (2-1/2″ spherical). |
| -300 | 304 SS float rated 300 psig (20.7 bar) and 0.7 min. s.g. (2-1/2″ spherical). |