KNF FP 7 Low-Pulsation Diaphragm Liquid Pump

Overview

The KNF FP 7 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 proprietary low-pulsation diaphragm actuation principle—utilizing a precision-machined PPS pump head, chemically resistant elastomeric diaphragms (EPDM or PTFE), and optimized valve geometry—the FP 7 delivers stable, pulse-minimized flow with minimal backflow and zero oil carryover. Its design adheres to the fundamental requirements of ISO 8573-1 Class 0 (oil-free air/gas) and supports applications where media purity, repeatability, and long-term reliability are non-negotiable. Unlike rotary vane or peristaltic alternatives, the FP 7 operates without lubricants, seals, or sliding contacts that degrade or leach, making it suitable for continuous duty in regulated settings including medical device fluidics, analytical sample introduction, and semiconductor wet-process sub-systems.

Key Features

• Low-pulsation fluid transfer with <0.5% flow ripple (RMS), critical for HPLC auxiliary dosing and microfluidic metering
• FDA-compliant wetted materials: EPDM and PTFE diaphragms; FKM/FFKM valve options for aggressive solvents and acids
• Self-priming capability up to 2 mWg suction lift, enabling reliable start-up without pre-filling
• True dry-run operation—no damage incurred during transient air-only conditions
• Digital speed control interface (0–10 V or PWM) for real-time flow modulation and integration into PLC or LabVIEW-controlled systems
• Brushless DC motor option ensures >10,000 h MTBF and consistent torque across voltage fluctuations (6–24 VDC)
• Ultra-low acoustic emission (<35 dB(A) at 10 cm), validated per ISO 3744 for quiet laboratory integration
• Compact footprint (72 × 42 × 35 mm) and minimal mass (125 g) support embedded OEM instrumentation design

Sample Compatibility & Compliance

The FP 7 is validated for use with neutral, mildly acidic, and moderately corrosive liquids—including aqueous buffers, IPA, dilute HCl/HNO₃, and hydrogen peroxide solutions—when configured with FFKM valves and PTFE diaphragms. It complies with EU Directive 2014/30/EU (EMC), RoHS 2011/65/EU, and carries CE marking for safe operation within laboratory and industrial equipment. For pharmaceutical and food-grade applications, material declarations conform to USP Class VI and FDA 21 CFR 177.2600 for elastomers. While not certified to IEC 61000-6-2/4 for full EMC immunity, its EMI profile meets typical Class B limits for laboratory instrumentation when installed with standard shielded cabling and local filtering.

Software & Data Management

The FP 7 operates as a standalone analog-controlled device but integrates seamlessly into automated workflows via optional digital control modules (e.g., KNF’s NFD series interface boards). These enable serial communication (RS-485 Modbus RTU), real-time speed/flow logging, and event-triggered status reporting (e.g., stall detection, thermal warning). Audit trails generated by host systems can satisfy GLP/GMP data integrity requirements under FDA 21 CFR Part 11 when paired with electronic signature-capable SCADA platforms. No embedded firmware update capability is provided—firmware remains fixed to ensure deterministic timing behavior required in safety-critical fluid paths.

Applications

• Reagent delivery and waste aspiration in benchtop analyzers (e.g., blood gas, immunoassay, and environmental TOC instruments)
• Chemical feed control in clean-in-place (CIP) and sterilize-in-place (SIP) subsystems for bioreactors and filling lines
• Continuous sampling and dilution in stack emission monitoring (CEMS) and ambient air quality analyzers
• Precision ink metering in industrial inkjet printheads and printed electronics deposition systems
• Humidification and purge gas conditioning in fuel cell test stations and wafer-level metrology tools
• Drug delivery actuation in portable diagnostic cartridges and point-of-care microfluidic devices

FAQ

Is the FP 7 suitable for pumping organic solvents such as acetone or THF?
Yes—when equipped with FFKM valves and PTFE diaphragms, the FP 7 demonstrates compatibility with common polar aprotic solvents; however, prolonged exposure to chlorinated hydrocarbons (e.g., chloroform) is not recommended.
Can the FP 7 be operated continuously at maximum pressure (1 bar rel.)?
Yes—its thermal management and brushless motor design permit indefinite duty cycle at rated pressure and flow, provided ambient temperature remains ≤40 °C and adequate ventilation is maintained.
Does KNF provide application-specific validation documentation?
Yes—upon request, KNF supplies material compatibility charts, lifetime test reports (per ISO 5801), and application notes aligned with ASTM D3924 (fluid system component testing) and IEC 60601-1 (medical electrical equipment).
What is the expected service life under typical lab-use conditions?
With proper mounting orientation and avoidance of particulate-laden fluids, the FP 7 achieves ≥20,000 hours of operation before diaphragm replacement, based on accelerated life testing per DIN EN 60068-2-64.