The LS200 Series liquid level switch is a robust, float-activated instrument engineered to detect rising liquid levels inside pressurized vessels and trigger alarm or shutdown outputs in electric or pneumatic control circuits. Purpose-built for the demanding conditions of gas compressor scrubbers, it handles up to 2000 psi working pressure and is available in both SPDT electric and pneumatic dump valve operator configurations — mounting directly into the vessel wall via a 2 in. NPT connection.
The LS200 Series liquid level switch is a field-proven instrument for high-pressure liquid detection in gas compressor scrubbers and process vessels. Activated by a 304 stainless steel float, it responds only to rising liquid levels — eliminating false trips from liquid movement or turbulence. The nickel-plated body delivers reliable corrosion resistance in demanding gas field environments, while electric and pneumatic model variants allow the LS200 to interface with both conventional electrical alarm circuits and pneumatic dump valve control systems. Direct 2 in. NPT vessel mounting or external float chamber installation makes integration straightforward in new builds and retrofit projects alike.
Key technical parameters for the LS200 Series liquid level switch family are listed below. Specifications apply to the standard electric model (LS200) unless otherwise indicated. All values are provided for engineering reference and procurement purposes.
| Parameter | Specification |
|---|---|
| Switch Type (LS200 Electric) | SPDT Snap-Switch (optional DPDT on select models) |
| SPDT Switch Rating | 5 A @ 125–250–480 VAC; ½ A @ 125 VDC; ¼ A @ 250 VDC; 2 A @ 6–30 VDC Resistive; 1 A @ 6–30 VDC Inductive |
| DPDT Switch Rating (Optional) | 10 A @ 125–250 VAC; ½ A @ 125 VDC; ¼ A @ 250 VDC; 10 A @ 6–24 VDC Inductive/Resistive |
| Wiring (LS200 Electric) | 18 AWG × 36 in. (1.0 mm² × 916 mm) |
| Pressure Rating | 2000 psig (13.8 MPa) [138 bar] |
| Temperature Rating (LS200 Electric) | -20° to 300°F (-29° to 149°C) |
| Process Connection | 2 in. NPT |
| O-ring Material (LS200 Electric) | Viton |
| Body Material | Nickel-Plated Steel; Optional 316 Stainless Steel |
| Float Material | 304 Stainless Steel |
| Minimum Specific Gravity (LS200, Std.) | 0.55 (standard float); 0.7 (with 1 in. extension) |
| Minimum Specific Gravity (LS200NDVO, Std.) | 0.63 (standard float); 0.73 (with 1 in. extension) |
| Hazardous Area Listing | cCSAus Class I, Division 1, Groups C & D |
| Canadian Registration (ABSA) | LS200: 0F01476.2 |
| Insertion Depth – LS200 Standard | 4.6 in. (standard); 5.6 in. (with 1 in. extension) |
| Vertical Clearance – LS200 Standard | 2.8 in. (standard); 3.15 in. (with 1 in. extension) |
| Pneumatic Regulator Range (LS200NDVOR) | 0–75 psig (0–517 kPa); Max Input: 300 psig (2.07 MPa) |
| Vent Valve (LS200N) | 2-way N.C., 1/16 in. (2 mm) orifice, Viton seat; Inlet: 1/8 in. NPT; Outlet: 3/8 in. NPT |
| Approximate Shipping Weight (LS200) | 6 lb. 12 oz. (approx. 3.06 kg) |
| Shipping Dimensions | 13½ × 4½ × 3½ in. |
The LS200 Series operates on a straightforward float-activated principle. A 304 stainless steel float is suspended inside the process vessel — either directly through the 2 in. NPT vessel wall connection or within a separately mounted external float chamber. As liquid accumulates in the vessel, the rising fluid surface lifts the float upward along its operating shaft.
When the liquid reaches the preset trip level, the float displacement drives an internal mechanism that actuates the output device. On electric models, this snaps the SPDT (or DPDT) switch contacts from their normal position to the alarm or shutdown state — sending a signal to the connected engine ignition, motor control circuit, or alarm panel. On pneumatic models, the float movement opens or closes a pneumatic vent valve; the resulting change in signal pressure actuates a connected dump valve operator to drain accumulated liquid from the vessel automatically.
Critically, the LS200 is engineered to trip only on rising liquid level — it does not respond to falling liquid or to momentary liquid disturbance caused by vessel vibration or slugging flow. This selective activation behaviour prevents spurious shutdowns in the turbulent operating environment typical of gas compressor scrubbers. Once the liquid level falls below the float's operating point, the instrument resets and is ready for the next detection cycle.
The LS200 Series is a float-activated level switch primarily designed for gas compressor scrubber applications. It triggers an alarm or shutdown signal when liquid rises to a preset level inside a pressure vessel or scrubber. It is also used in production separators, knockout drums, and other high-pressure process vessels where reliable liquid level detection is required to protect downstream equipment.
The LS200 Series is rated for 2000 psig (13.8 MPa / 138 bar) working pressure. This high pressure rating allows the switch to be installed directly inside pressurized vessels — including gas compressor scrubbers and high-pressure separators — without requiring additional pressure isolation equipment at the instrument connection point.
The LS200 electric model actuates an SPDT snap-switch (optional DPDT) to deliver an alarm or shutdown output to an engine ignition or motor control circuit. The pneumatic models — LS200N, LS200NDVO, and LS200NDVOR — instead produce a pneumatic signal that operates a dump valve or similar pneumatic device. The LS200NDVOR includes an integrated filter/regulator and pressure gauge, while the LS200NDVO is supplied without the regulator for installations where a system regulator is already present.
Yes. The LS200 Series carries a cCSAus listing for Class I, Division 1, Groups C and D hazardous locations, and is Canadian registered under ABSA registration number 0F01476.2. This certification makes the LS200 suitable for installation in areas where flammable gases or vapors may be present under normal operating conditions — a common classification for gas compressor stations and upstream processing facilities.
Yes. In addition to direct vessel wall mounting, the LS200 is compatible with an external float chamber accessory (part 15700799, rated to 2000 psi and 400°F). The external chamber allows the switch to be positioned outside the vessel for easier access, testing, and maintenance — without requiring the process vessel to be depressurized or opened for routine inspection of the level switch.
The standard LS200 float operates in fluids with a specific gravity of 0.55 and above at 2000 psi, covering most hydrocarbon condensates and produced water streams. With the optional 1 in. float shaft extension, the minimum specific gravity increases to 0.70. For the pneumatic LS200NDVO model, the minimum is 0.63 standard and 0.73 with extension. Matching the correct float configuration to the actual process fluid density is important for reliable level detection.
Our engineers will recommend the right LS200 Series model for your scrubber or process vessel application, send you the full technical datasheet, and provide a competitive quote.
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