KNF FP25 Low-Pulsation Diaphragm Liquid Pump

Overview

The KNF FP25 is a compact, high-integrity diaphragm liquid pump engineered for precise, contamination-free fluid handling in demanding analytical and process-critical environments. Based on KNF’s proven positive displacement principle, the FP25 employs a reciprocating elastomeric diaphragm actuated by an electromagnetic or brushless DC motor to generate controlled volumetric displacement—eliminating oil-lubricated components and ensuring zero media contact with lubricants or seals. Its low-pulsation design minimizes pressure fluctuations (< ±2% peak-to-peak under steady-state conditions), making it suitable for applications requiring stable flow profiles, such as reagent delivery in HPLC sample introduction, calibration fluid metering in emission analyzers, or dosing in microfluidic diagnostic platforms. The pump operates reliably across a wide chemical compatibility spectrum—from aqueous buffers and organic solvents to aggressive acids and halogenated media—thanks to its chemically resistant wetted path constructed from PPS (polyphenylsulfone) housing, EPDM or FFKM valves, and PTFE-coated diaphragms.

Key Features

• Low-pulsation operation optimized for precision metering and sensitive detection systems
• Fully oil-free, dry-run capable architecture—no risk of lubricant migration or cross-contamination
• Self-priming up to 3 mWg (≈300 mbar vacuum), enabling reliable startup without pre-filling
• Maintenance-free design with no sliding seals, bearings, or lubrication points in the fluid path
• Digital speed control interface supporting analog (0–10 V) or PWM input for real-time flow modulation
• NSF/ANSI 51 and FDA 21 CFR Part 11 compliant materials—validated for food, pharmaceutical, and clinical use
• Compact footprint (approx. 85 × 55 × 40 mm) and ultra-light mass (240 g) for integration into space-constrained OEM instruments
• High power efficiency: 2.9 W nominal input enables battery-powered or low-power embedded system deployment

Sample Compatibility & Compliance

The FP25 accommodates a broad range of liquid media—including deionized water, ethanol, isopropanol, 10% HNO₃, 5% NaOH, and perfluorinated solvents—without degradation of wetted components. Chemical resistance is validated per ASTM D471 and ISO 1817 standards for elastomer exposure. All wetted materials comply with USP Class VI biocompatibility requirements and EU Regulation (EC) No. 1935/2004 for food-contact applications. The pump meets IEC 61000-6-2 (immunity) and IEC 61000-6-4 (emissions) for electromagnetic compatibility in laboratory and industrial settings. It supports GLP/GMP workflows via traceable speed calibration logs when integrated with KNF’s optional digital controller modules.

Software & Data Management

While the FP25 operates as a standalone analog-controlled device, it is fully compatible with KNF’s NFD (Networked Fluid Dynamics) ecosystem for system-level integration. When paired with KNF’s digital motor drivers (e.g., NFD-DC2), users gain access to firmware-updatable parameters including ramp profiles, stall detection thresholds, and runtime counters—all accessible via Modbus RTU or ASCII serial protocol. Audit trails for speed setpoints and operational hours can be exported for 21 CFR Part 11–compliant recordkeeping. No proprietary software installation is required; configuration is performed through standard terminal emulators or OEM-developed GUIs.

Applications

• Analytical instrumentation: Carrier gas humidification in GC-MS, wash buffer delivery in ELISA readers, and mobile phase degassing support
• Environmental monitoring: Continuous sampling of stack emissions, condensate extraction in particulate matter analyzers
• Medical diagnostics: Reagent aspiration in point-of-care blood analyzers and dialysis fluid metering
• Semiconductor manufacturing: Ultra-pure chemical dosing for wafer cleaning baths and photoresist dispense
• Food & beverage QA: Sanitizer circulation in CIP skids and flavor concentrate blending verification
• Fuel cell R&D: Humidified air supply to PEM membrane test stations with pulse-free flow stability

FAQ

Is the FP25 certified for use in regulated pharmaceutical manufacturing?
Yes—the pump’s wetted materials are FDA-compliant and meet USP Class VI requirements. When integrated with validated control systems, it supports GMP documentation protocols.
Can the FP25 handle viscous fluids such as glycerol or silicone oil?
It is optimized for low-to-medium viscosity liquids (< 500 cP). For viscosities exceeding 100 cP, flow rate decreases nonlinearly; consult KNF’s application engineering team for derating curves.
What is the expected service life under continuous operation?
Rated for >20,000 hours MTBF at rated load and ambient temperatures between 5–40°C, based on accelerated life testing per ISO 13849-1.
Does KNF offer custom configurations for OEM integration?
Yes—custom inlet/outlet port geometry, modified electrical interfaces (e.g., M8 connectors), and application-specific firmware are available under NDA.
How does the FP25 achieve low pulsation without dampeners or accumulators?
Through optimized diaphragm kinematics, dual-head phasing (in multi-pump variants), and precision-machined valve timing—reducing inherent flow ripple at the source rather than masking it downstream.