Jerguson Gage & Valve — Level Switches
JMLS Horizontal Mount Magnetic Level Switch
Bulletin JS100.02 — Magnetic snap-action level switch using repelling permanent magnets. All 316SS wetted parts, integral conduit box, CSA Class I Group C & D, NEMA 4X. Rated to 1,500 PSIG with NPT and flanged process connections.
Operation
Operation is achieved using the time-proven principle of repelling magnetic forces. One permanent magnet — the primary magnet — forms part of a float assembly which rises and falls with changing liquid level. The secondary magnet is positioned within the enclosure so that the adjacent poles of the two magnets repel each other through a non-magnetic, stainless steel barrier.
A change in liquid level moves the float through its permissible range of travel, causing the float magnet to pivot and repel the switch magnet. The resulting snap action of the repelling magnets actuates the switch. The design includes a float, pivot, primary magnet, secondary magnet, enclosure, switch mechanism, and terminal block.
Key Features
Magnetic Snap-Action
Positive, reliable switching via repelling permanent magnets — no springs to fatigue or fail.
All 316SS Wetted Parts
T-316 stainless steel body and trim for broad chemical compatibility and corrosion resistance.
SPDT or DPDT Contacts
Multiple switch form options from standard to high-amp, high-temperature, hermetically sealed, and gold-plated.
Integral Conduit Box
Factory-mounted conduit box with terminal block simplifies field wiring.
Magnetic Latching
Snap-action latching provides a definitive switching point with nominal 1" differential.
CSA Certified — Class I, Group C & D, NEMA 4X
Rated for hazardous locations and outdoor/washdown environments.
Typical Applications
Petroleum Processing
Fuels, lubricating oils, hydraulic fluids, separators, treaters, crude oil, fuel-water interfaces.
Chemical Processing
Acids, alkalis, ammonia, paint, lacquer, peroxides, alcohols, printing inks, freon.
Food Processing
Beverages, fruit juices, cooking oils.
Pharmaceutical & Cosmetic
Liquids, emulsions, lotions, solutions.
Marine Operations
Fuel oil, hydraulic fluid, bilge level alarms, sea water, coolant, condensate, cargo levels.
Reactor Operation
Level control, alarm signaling.
Cryogenic Liquids
Liquid methane, nitrogen, carbon dioxide, oxygen.
Water Industry
Flood control, reservoir levels.
General
Leak detection, overflow alarm, low level alarm in evaporators.
Technical Specifications
| Specification | Value |
|---|---|
| Pressure Rating | 1,500 PSIG |
| Minimum Specific Gravity | 0.50 |
| Maximum Ambient Temperature | 250°F (121°C) |
| Switch Differential | Nominal 1" |
| Certification | CSA Class I, Group C & D, NEMA 4X |
Dimensional Reference — Typical JMLS2100
| Dimension / Connection | Specification |
|---|---|
| Maximum Float Travel | 2.500" (64 mm) |
| Process Connection | 1-1/2" NPT |
| Float Reference Length | 3.125" (79 mm) |
| Overall Reference Length | 5.750" (146 mm) |
| Conduit Entry | 1" FNPT |
| Conduit Box Reference | 2.000" (51 mm) |
Bulletin JS100.02 — 9/2014. Consult factory for current dimensional drawings.
Model Selection — Switch Form & Function
| Code | Switch Form | Max. Ambient | Max. Process | Switch Rating |
|---|---|---|---|---|
| 1 | SPDT Standard Switch | 250°F (121°C) | 450°F (232°C) | 5A @ 120/240 VAC |
| 2 | DPDT Standard Switch | 250°F (121°C) | 450°F (232°C) | 3(5)A @ 24 VDC¹ |
| 3 | SPDT High Amp Rating | 250°F (121°C) | 250°F (121°C) | 11A @ 120/240 VAC |
| 4 | DPDT High Amp Rating | 250°F (121°C) | 250°F (121°C) | 1(2)A @ 24 VDC¹ |
| 5 | SPDT High Temperature | 400°F (204°C) | 750°F (398°C) | 5A @ 120/240 VAC (N.R. for DC) |
| 6 | DPDT High Temperature | 400°F (204°C) | 750°F (398°C) | 5A @ 120/240 VAC (N.R. for DC) |
| 7 | SPDT Hermetically Sealed | 250°F (121°C) | 400°F (204°C) | See note |
| 8 | DPDT Hermetically Sealed | 250°F (121°C) | 400°F (204°C) | 3(5)A @ 24 VDC¹ |
| 9 | SPDT Gold Plated | 250°F (121°C) | 250°F (121°C) | See note |
| 0 | DPDT Gold Plated | 250°F (121°C) | 250°F (121°C) | 0.5(1)A @ 24 VDC |
¹ DC Rating = Inductive listed before resistive. Example: 3(5) = 3A inductive or 5A resistive @ 24 VDC.
Process Connections
Threaded NPT Connections
| Connection | Pressure Rating | Code |
|---|---|---|
| 1-1/2" NPT | 1,500 PSIG @ 100°F | 00 |
| 2" NPT | 1,500 PSIG @ 100°F | 70 |
Flanged Connections
| Connection | Pressure Rating | Carbon Steel Code | 316SS Code |
|---|---|---|---|
| 2-1/2" 150# RF Threaded | 285 PSIG @ 100°F | 11 | 13 |
| 2-1/2" 300# RF Threaded | 740 PSIG @ 100°F | 21 | 23 |
| 2-1/2" 600# RF Threaded | 1,480 PSIG @ 100°F | 31 | 33 |
| 3" 150# RF Threaded | 285 PSIG @ 100°F | 41 | 43 |
| 3" 300# RF Threaded | 740 PSIG @ 100°F | 51 | 53 |
| 3" 600# RF Threaded | 1,480 PSIG @ 100°F | 61 | 63 |
Float Options & Extensions
| Code | Option / Extension | Min. S.G. (SS Float) | Min. S.G. (Poly Float) |
|---|---|---|---|
| FE0800 | Float Extension 8.00" | 0.89 | 0.82 |
| FE0600 | Float Extension 6.00" | 0.85 | 0.78 |
| FE0400 | Float Extension 4.00" | 0.79 | 0.73 |
| FE0300 | Float Extension 3.00" | 0.73 | 0.69 |
| P | Polypropylene Float | Min. S.G. = 0.40 (No Extension); Max. 250°F | — |
| BW | Back Welded Flange | — | — |
Float extension code example: FE0225 = 2-1/4" extension.
Typical Model Number
JMLS 2 1 00
| Position | Code | Description |
|---|---|---|
| Model | JMLS | Horizontal Mount Magnetic Level Switch |
| Material | 2 | T-316 Stainless Steel Body and Trim |
| Switch | 1 | SPDT Standard Switch |
| Connection | 00 | 1-1/2" NPT |
Additional float extension and construction options may be specified as applicable.
Ready to specify the JMLS?
Contact Northeast Controls — 1-201-327-7660 — sales@nciweb.com