Xufeng DM-L6 Petroleum Demulsibility Tester

Overview

The Xufeng DM-L6 Petroleum Demulsibility Tester is a precision-engineered instrument designed for the quantitative evaluation of water separation behavior in petroleum products and synthetic lubricants. It operates on the principle of controlled mechanical agitation followed by gravimetric phase separation monitoring—directly aligned with standardized demulsibility assessment protocols defined in GB/T 7305, ASTM D1401, and ISO 6614. The instrument measures the time required for an oil–water emulsion to separate into distinct layers under strictly regulated thermal and hydrodynamic conditions. This performance metric—commonly reported as “demulsibility rating” (e.g., “40–37–0 mL at 60 min”)—serves as a critical quality indicator for turbine oils, hydraulic fluids, gear oils, and other industrial lubricants where water ingress may compromise film strength, accelerate oxidation, or promote corrosion.

Key Features

• Integrated dual-zone temperature control system: A high-stability glass bath (Φ300 × 300 mm) maintains uniform thermal distribution across all six test positions within ±0.5 °C over the full operating range (ambient to 95 °C).
• Six-position parallel testing architecture: Enables statistically robust inter-sample comparison and batch qualification per ASTM D1401 Section 7.2 and GB/T 7305 Clause 6.1.
• Automated 1500 rpm stirring mechanism: Brushless DC motor-driven stirrer head rotates >120° to access each cylinder sequentially; real-time speed feedback is continuously displayed on the front panel.
• Independent 6-channel timing system: Each channel initiates agitation upon button press, terminates stirring after exactly 5 min, then initiates separation timing. Visual LED pulse every 5 min supports manual observation intervals; audible alarm triggers at 60 min endpoint.
• Modular mechanical design: Separation of bath assembly and electronics enclosure facilitates maintenance, calibration verification, and GLP-compliant traceability of thermal and motion subsystems.
• Compliance-ready hardware interface: All timers, temperature sensors, and motor controllers are hardwired without embedded firmware dependencies—supporting audit trails required under ISO/IEC 17025 and internal QC documentation procedures.

Sample Compatibility & Compliance

The DM-L6 accommodates standard cylindrical test vessels (Φ32 × 225 mm) conforming to GB/T 7305 and ASTM D1401 dimensional requirements. With minor cylinder substitution (e.g., Φ25 × 225 mm), it also supports GB/T 7605-2008 for in-service turbine oil analysis. The instrument meets essential metrological criteria for repeatability (≤2 min inter-test deviation per ISO 6614 Annex B) and thermal homogeneity (±0.3 °C radial gradient at 82 °C). Its mechanical agitation profile satisfies ASTM D1401’s requirement for “uniform vortex formation without splashing.” No software-based data logging is included; raw observations are recorded manually per regulatory expectations for Class II demulsibility testing in refinery QC labs and third-party certification facilities.

Software & Data Management

The DM-L6 operates as a standalone electromechanical platform with no embedded operating system or network connectivity. All operational parameters—including setpoint temperature, actual bath temperature, real-time stirrer RPM, and elapsed separation time per channel—are presented via analog/digital hybrid indicators on the front panel. This architecture eliminates cybersecurity risks, avoids FDA 21 CFR Part 11 validation burdens, and ensures uninterrupted operation in environments with electromagnetic interference (e.g., near large motors or switchgear). For laboratories requiring electronic recordkeeping, external USB thermocouple loggers or time-synchronized video documentation may be integrated without modifying the instrument’s certified configuration.

Applications

• Quality release testing of new turbine oils, compressor oils, and hydraulic fluids against OEM specifications (e.g., GEK 32568, Siemens TLV 9013).
• Condition monitoring of in-service lubricants in power generation, marine propulsion, and steel mill applications per GB/T 7605-2008.
• R&D screening of demulsifier additive packages during formulation development.
• Third-party conformity assessment for ISO 8573-2 compressed air system lubricants.
• Technical support for root-cause analysis of bearing failures linked to water-induced emulsion stability loss.

FAQ

Does the DM-L6 comply with current editions of ASTM D1401?
Yes—the instrument implements the core physical test conditions specified in ASTM D1401-22, including temperature control accuracy, stirrer geometry, and timing sequence. Note that ASTM D1401 does not mandate instrument certification; compliance is verified through method validation per Section 11.
Can the unit be used for biodiesel or bio-lubricant testing?
While not explicitly referenced in ASTM D1401, the DM-L6 has been successfully applied to FAME-based fuels and ester-based synthetics in accordance with modified internal test protocols—provided viscosity remains below 100 cSt at test temperature.
Is calibration documentation provided with shipment?
Each unit ships with a factory calibration certificate covering bath temperature uniformity (NIST-traceable RTD), stirrer speed accuracy (optical tachometer verified), and timer linearity (±0.2 s/hour deviation). Annual recalibration is recommended per ISO/IEC 17025 Clause 6.5.
What maintenance is required for long-term reliability?
Routine cleaning of glass bath interior and cylinder holders with isopropanol; biannual inspection of stirrer shaft alignment and motor brush wear (DC motor); annual verification of thermal sensor drift using a calibrated reference thermometer.
Are replacement cylinders available with different diameters?
Yes—Xufeng supplies optional Φ25 mm cylinders for GB/T 7605-2008 compliance and Φ40 mm variants for research-scale emulsion studies, all manufactured from borosilicate glass meeting ASTM E438 Type I, Class A tolerances.