SSI Series III Constant Flow High-Pressure Piston Pump

Overview

The SSI Series III Constant Flow High-Pressure Piston Pump is an engineered solution for precision liquid delivery in analytical, preparative, and process-critical laboratory environments. Based on proven positive displacement piston architecture, it operates via a digitally synchronized stepper motor driving a dual-piston reciprocating mechanism—ensuring continuous, pulse-minimized flow without reliance on check valves alone. The integrated high-speed cam-assisted priming system enables rapid solvent uptake with minimal air entrapment, while the miniature diaphragm-type pulse damper reduces baseline noise to <0.1% pressure ripple (measured at 1 mL/min, 1000 psi), meeting stringent requirements for HPLC, UHPLC, and microfluidic applications. Unlike peristaltic or syringe-based alternatives, the Series III delivers true constant-flow behavior across its full operating range—even under dynamic backpressure fluctuations—making it suitable for gradient elution, reaction quenching, and controlled reagent addition where volumetric fidelity and temporal reproducibility are non-negotiable.

Key Features

• Integrated pressure transducer with real-time LED display of instantaneous pressure and flow rate, plus programmable high/low pressure limits with automatic shutdown
• On-line pump head self-cleaning function activated via front-panel rapid flush mode—reducing maintenance intervals and minimizing cross-contamination risk between solvents or samples
• Modular wetted-path construction: interchangeable pump heads available in PEEK (for aggressive organic solvents and biocompatible workflows) or 316L stainless steel (for high-pressure inert applications up to 6000 psi)
• Digital logic control architecture with RS232 interface supports external triggering, synchronized multi-pump operation, and integration into automated platforms compliant with LabVIEW, MATLAB, or custom SCADA systems
• Front-panel five-key interface enables intuitive local configuration—no software installation required for routine operation, calibration, or safety limit setting
• Low pulsation design (<0.2% RSD at 1 mL/min, 2000 psi) validated per ISO 5725-2:1994 guidelines for precision measurement systems

Sample Compatibility & Compliance

The Series III accommodates a broad spectrum of mobile phases—including acetonitrile, methanol, THF, DMF, aqueous buffers, and mildly corrosive reagents—without degradation of sealing integrity or flow accuracy. PEEK pump heads comply with USP Class VI biocompatibility standards and are certified for use in GLP-regulated preclinical assay development. Stainless steel configurations meet ASTM F899 specifications for corrosion resistance in chloride-containing media. All firmware and control logic adhere to IEC 61000-6-3 EMC emission standards. Data logging capabilities—including timestamped pressure/flow events and fault codes—support audit-ready documentation for FDA 21 CFR Part 11-compliant environments when paired with validated third-party acquisition software.

Software & Data Management

While fully functional as a standalone instrument, the Series III supports bidirectional RS232 communication for remote parameter adjustment, real-time data streaming, and event-triggered actions (e.g., pause on overpressure, initiate flush on flow deviation >1.5%). Optional SSI PumpControl Suite (v3.2+) provides graphical monitoring, method storage, and export of CSV-formatted logs compatible with LIMS and ELN platforms. Audit trails record all user-initiated changes—including flow setpoint modifications, pressure limit adjustments, and flush cycles—with operator ID and timestamp. Firmware updates are delivered via signed binary packages to ensure traceability and prevent unauthorized modification.

Applications

• HPLC and UHPLC solvent delivery in research, QC, and method development labs requiring long-term flow stability (≤0.2% RSD over 24 h)
• Preparative chromatography systems where precise fraction collection depends on consistent volumetric throughput
• Chemical synthesis reactors requiring stoichiometric reagent dosing under elevated backpressure (e.g., hydrogenation, polymerization)
• Microreactor and lab-on-chip interfaces demanding low-dead-volume, pulse-free infusion
• Educational instrumentation for teaching fluid mechanics, pump hydraulics, and analytical system integration
• Calibration reference pumps in metrology labs performing gravimetric flow verification per ISO 4064-2

FAQ

What materials are in contact with fluid? Can I switch between PEEK and stainless steel pump heads?

Yes—wetted components are fully modular. PEEK heads are standard for organic/aqueous mixtures and biological buffers; stainless steel heads are field-replaceable for high-pressure inert applications. No tools required for head exchange.
Does the pump support gradient formation when paired with other units?

Yes—via RS232 synchronization or analog voltage input, multiple Series III units can be coordinated to generate binary or ternary gradients with sub-second timing resolution.
How is flow accuracy verified and maintained over time?

Each unit ships with NIST-traceable calibration certificate. Field recalibration is performed using gravimetric measurement against certified reference weights; procedure documented in Appendix B of the Operator Manual.
Is the pressure sensor user-replaceable?

No—the piezoresistive sensor is factory-calibrated and sealed within the pump housing. Replacement requires return-to-factory service to preserve metrological integrity.
Can the pump operate unattended for extended periods (e.g., overnight runs)?

Yes—built-in thermal protection, pressure fault detection, and non-volatile memory retain settings after power loss. Continuous operation beyond 72 h is validated under ISO 9001 production testing.