PULUODY PLD-0248A Cold Filter Plugging Point (CFPP) Tester per SH/T 0248

Overview

The PULUODY PLD-0248A Cold Filter Plugging Point (CFPP) Tester is a precision-engineered instrument designed in strict accordance with the Chinese petroleum industry standard SH/T 0248—“Standard Test Method for Cold Filter Plugging Point of Diesel Fuel and Domestic Heating Oil.” It determines the lowest temperature at which a specified volume of diesel or middle distillate fuel can pass through a standardized 40 µm stainless steel wire mesh filter under a defined vacuum pressure of 1961 Pa (equivalent to 200 mm H₂O), while being cooled in 1 °C decrements. This measurement directly reflects the low-temperature operability of diesel fuels in modern high-pressure common-rail injection systems, where wax crystal formation and agglomeration may impair fuel flow and cause filter blockage. The instrument employs a dual-stage cascade refrigeration system based on hermetic compressors, enabling stable and reproducible thermal control from ambient down to –40 °C without reliance on external cryogenic media. Its digital PID temperature controller ensures thermal stability within ±1 °C across the entire operating range, critical for inter-laboratory method equivalence.

Key Features

• Integrated cascade compression refrigeration system with evaporative condenser and capillary throttling—eliminates need for liquid nitrogen or dry ice while maintaining consistent sub-zero bath performance.
• Digital microprocessor-based temperature controller with real-time display, programmable cooling ramp, and automatic endpoint detection logic aligned with SH/T 0248 procedural requirements.
• Electronically regulated vacuum suction assembly featuring calibrated U-tube manometer, constant-head water reservoir, diaphragm vacuum pump, and precision bleed valve for accurate 1961 Pa (±10 Pa) differential pressure application during filtration.
• Modular test cell architecture: includes ASTM-compliant sample cup, concentric jacketed cooling bath, standardized 363-mesh stainless steel filter holder, calibrated suction pipette, and magnetic stirrer for uniform thermal equilibration.
• Self-contained design with internal anhydrous ethanol coolant circulation—no external chiller required; optimized heat transfer coefficient ensures rapid thermal response and minimal temperature gradient across the bath.
• Compliance-ready construction: all electrical components meet IEC 61010-1 safety standards; enclosure rated IP20 for laboratory indoor use; grounding continuity and leakage current fully verified per factory QC protocol.

Sample Compatibility & Compliance

The PLD-0248A is validated for use with diesel fuels (including ultra-low-sulfur diesel, biodiesel blends up to B20), heating oils (Class C and D per GB/T 255), and kerosene-type jet fuels where CFPP assessment is specified. It supports sample volumes of 20–45 mL per test, accommodating both manual and semi-automated workflow integration. While SH/T 0248 is the primary reference method, the instrument’s physical configuration and operational parameters are functionally equivalent to ISO 3015 and ASTM D6371, facilitating cross-standard correlation studies. All mechanical and thermal subsystems undergo annual calibration traceable to CNAS-accredited metrology labs (certificate included). The system supports GLP documentation workflows: temperature logs, pressure events, and test timestamps are stored internally with optional RS232/USB export for audit trail generation compliant with ISO/IEC 17025 Clause 7.7.

Software & Data Management

The embedded firmware provides full method execution control—including automated stepwise cooling, pressure stabilization verification, visual endpoint confirmation via LED indicator, and pass/fail logic per SH/T 0248 Section 8.2. Test records (date/time, bath temperature, observed plugging point, operator ID, and ambient conditions) are retained in non-volatile memory for ≥1000 cycles. Optional PC connectivity enables CSV export for LIMS integration and statistical process control (SPC) charting (e.g., X-bar/R charts per ASTM E2587). Audit trail functionality meets basic FDA 21 CFR Part 11 requirements for electronic records: user authentication, immutable event logging, and timestamped action history—no electronic signatures required unless paired with validated third-party laboratory software.

Applications

• Quality assurance testing of refinery-produced diesel batches prior to dispatch.
• R&D evaluation of cold-flow improver (CFI) additive efficacy in paraffinic and hydrotreated feedstocks.
• Field laboratory verification of fuel compliance with regional winter-grade specifications (e.g., GB 19147 Class 0, –10, –20, –35).
• Third-party certification testing for OEM fuel approval programs requiring SH/T 0248 conformance.
• Interlaboratory comparison studies supporting method validation per ISO/IEC 17025 Clause 7.2.2.
• Training platform for petroleum technician certification courses accredited by provincial technical supervision bureaus.

FAQ

What is the difference between Cold Filter Plugging Point (CFPP) and Cloud Point?
CFPP measures the highest temperature at which fuel fails to pass through a standardized filter under vacuum, reflecting practical low-temperature operability; cloud point indicates the onset of wax crystallization, a thermodynamic phase transition not directly linked to filterability.
Does the PLD-0248A support ASTM D6371 testing?
Yes—the mechanical configuration, filtration geometry, pressure control, and cooling rate profile comply with ASTM D6371 Annex A1; minor procedural adaptations (e.g., timing thresholds) are implemented via firmware configuration.
Is anhydrous ethanol the only approved heat transfer fluid?
Per SH/T 0248 Section 5.2 and instrument safety certification, only anhydrous ethanol (≥99.7% purity) is permitted as the bath medium; methanol or ethylene glycol mixtures are prohibited due to viscosity, flammability, and thermal expansion risks.
How often must the 363-mesh filter be replaced?
Filters are single-use per SH/T 0248 Section 6.3; reuse introduces contamination and pore deformation risk—each test requires a new certified filter (supplied in validated lots with certificate of conformance).
Can the unit operate continuously at –40 °C?
Yes—the cascade refrigeration system is rated for continuous operation at –40 °C for up to 8 hours; extended runtime requires periodic defrost cycle activation via front-panel menu to prevent evaporator frost accumulation.