FW Murphy MLS Series: A Reliable Choice for Industrial Liquid Level Monitoring

In the field of industrial automation, liquid level monitoring is a critical aspect of ensuring safe equipment operation and optimizing production processes. FW Murphy, a globally renowned manufacturer of industrial control equipment, has established its MLS series magnetic level switches as an ideal solution for liquid level monitoring in harsh working conditions. These switches are widely applied across industries such as oil and gas, chemicals, power generation, and agricultural irrigation, thanks to their exceptional performance and reliability.

I. Product Overview: Designed for Harsh Environments

The FW Murphy MLS series magnetic level switches operate on the principle of float activation, using magnetic coupling to trigger an electrical SPDT reed switch for precise liquid level signal transmission. Specifically engineered for demanding applications like gas compressor scrubbers, these switches withstand high pressures, extreme temperatures, and corrosive media, ensuring long-term stable operation. Their key advantages include:

• High-Pressure Rating: Rated for working pressures up to 2000 psi (138 bar), far exceeding comparable products, making them suitable for high-pressure gas processing systems.

• Wide Temperature Range: Standard models support operating temperatures from -29°C to 149°C, while extended chambers can handle up to 204°C, meeting extreme environmental requirements.

• All-Stainless Steel Construction: The valve body, cover, and float are all made of 304 stainless steel, offering excellent corrosion resistance and mechanical strength.

• Safety Certifications: Compliant with ANSI/ISA 12.27.01 standards (single seal) and certified by CSA OF12013.2 C, ensuring safety and regulatory compliance.

II. Technical Features: Precision, Reliability, and Versatility

1. Core Parameters and Model Selection

The MLS series offers 1.5-inch and 2-inch NPT female threaded connections, allowing direct installation on gas scrubber walls or connection via external float chambers. Standard models (e.g., MLS-015, MLS-020) provide basic liquid level detection, while test-function models (e.g., MLS-015-TF, MLS-020-TF) integrate an inline test button for verifying switch operation without draining the medium, significantly improving maintenance efficiency.

2. Electrical and Fluid Compatibility

• Electrical Specifications: Supports 30VAC/VDC voltage with a maximum current of 75mA, and conductor requirements range from AWG 26 (minimum) to 16 (maximum), ensuring compatibility with various control systems.

• Fluid Density Adaptability: Without an extension rod, suitable for fluids with a specific gravity ≥0.50; with a 1-inch extension rod, extends to fluids with a specific gravity ≥0.65, meeting diverse medium requirements.

3. Safety and Installation Guidelines

• Safety Warnings: Prohibited from use above 2000 psi (may cause permanent float deformation) and in hydrogen environments (risk of hydrogen embrittlement).

• Installation Requirements: Conductor cross-sectional area must be strictly controlled between AWG 16-26 to prevent mechanical stress-induced float ball jamming, ensuring long-term stable operation.

III. Application Scenarios: Multi-Industry Coverage with Flexible Solutions

1. Oil and Gas Industry

In natural gas compressor units, MLS series level switches monitor condensate levels in scrubbers to prevent liquid ingress into compressor cylinders, which could cause equipment damage. Their high-pressure tolerance (2000 psi) and corrosion-resistant design make them the top choice for offshore platforms and onshore gas fields operating under high-pressure conditions.

2. Chemical and Pharmaceutical Industries

During chemical production processes, MLS series switches precisely control liquid levels in reactors and storage tanks, preventing overflow or dry-running risks. Their all-stainless steel construction and ANSI/ISA-compliant seal design ensure long-term reliability in corrosive media.

3. Power Generation and Agricultural Irrigation

In power plant cooling water systems or agricultural irrigation pump stations, MLS series switches monitor water tank levels for automatic water replenishment or drainage control. Their wide temperature range (-29°C to 204°C) and extended chamber options enable adaptation to extreme outdoor environments.

IV. User Cases: Real-World Validation of Reliability

Case 1: Offshore Natural Gas Platform

An offshore platform adopted MLS-020-TF level switches to monitor compressor scrubber levels. The integrated test button allowed maintenance personnel to verify functionality without shutdowns, reducing maintenance time from 4 hours to 30 minutes and cutting annual maintenance costs by approximately $150,000.

Case 2: Chemical Enterprise Reactor Control

A chemical company used MLS-015 switches to control reactor liquid levels. The 304 stainless steel float operated without corrosion in strong acid media for three years, achieving a liquid level control accuracy of ±2mm and significantly improving product quality stability.

V. Conclusion: A Preferred Solution for Industrial Liquid Level Monitoring

The FW Murphy MLS series magnetic level switches stand out as a benchmark in industrial liquid level monitoring, thanks to their high-pressure tolerance, wide temperature operation, all-stainless steel construction, and integrated test functionality. Whether in oil and gas, chemicals, power generation, or agriculture, the MLS series offers customized solutions to enhance equipment reliability and reduce operational and maintenance costs. Choosing the MLS series means choosing safety, efficiency, and long-term value.