SSI Series III Constant Flow Pump

Overview

The SSI Series III Constant Flow Pump is a precision-engineered, high-pressure liquid delivery system designed for demanding laboratory and process-critical applications where consistent volumetric flow, chemical resistance, and long-term operational stability are essential. Based on proven positive displacement architecture—specifically a dual-piston reciprocating design with active pulse suppression—the Series III operates on the principle of controlled mechanical displacement to deliver highly reproducible flow rates independent of backpressure fluctuations up to 6000 psi. Its core innovation lies in the integration of an internal fast-fill cam mechanism and a compact, low-volume diaphragm-type pulse damper, which collectively reduce baseline noise and pulsation amplitude to levels suitable for sensitive analytical workflows, including preparative and analytical liquid chromatography, continuous-flow chemistry, and microreactor feed systems. Unlike peristaltic or syringe-based alternatives, the Series III maintains true constant flow across variable system impedance, making it particularly suited for applications requiring strict adherence to volumetric dosing protocols under dynamic pressure conditions.

Key Features

• High-pressure capability: Rated up to 6000 psi with 316L stainless steel fluid path; 5000 psi with PEEK for enhanced organic solvent compatibility and biocompatibility.
• Real-time digital monitoring: Integrated pressure transducer and dual-parameter LED display showing instantaneous flow rate and system pressure, with programmable high/low pressure limits for automated safety shutdown.
• On-line self-cleaning: Dedicated front-panel “Rapid Flush” function activates internal valve sequencing to purge residual solvents or precipitates from the pump head without disassembly—reducing maintenance downtime and cross-contamination risk.
• Digital and analog control flexibility: RS232 serial interface for remote command and data logging; optional analog voltage (0–10 V) or frequency (0–10 kHz) inputs for seamless integration into PLC-controlled or feedback-regulated processes.
• Modular pump head design: Quick-release mechanism enables tool-free replacement of wetted components (pistons, seals, check valves), supporting routine preventive maintenance and material-specific configuration (PEEK for aggressive solvents; stainless steel for high-temperature or high-pressure inert applications).
• Low-pulsation performance: Optimized cam profile and diaphragm damper yield flow ripple <0.5% RSD at nominal flow, meeting ISO 13842:2021 requirements for precision liquid metering devices used in GLP-compliant laboratories.

Sample Compatibility & Compliance

The Series III accommodates a broad range of liquid media—including aqueous buffers, acetonitrile/methanol mixtures, chlorinated solvents, and mildly corrosive reagents—when configured with PEEK fluidic components. Stainless steel variants comply with ASTM F899 for surgical-grade stainless alloys and meet USP Class VI biocompatibility testing criteria when specified. All configurations adhere to IEC 61010-1:2010 for electrical safety in laboratory equipment and support audit-ready operation under FDA 21 CFR Part 11 when paired with validated software platforms. Pressure and flow parameter logging via RS232 enables full traceability for GMP batch records and ISO/IEC 17025 method validation documentation.

Software & Data Management

While the Series III operates autonomously via its embedded microcontroller, its RS232 interface supports bidirectional communication with third-party laboratory information management systems (LIMS) or custom SCADA environments. Command syntax follows ASCII-based protocol standards, enabling scripting of multi-step sequences (e.g., gradient ramping, pressure-triggered hold, timed flush cycles). Time-stamped pressure and flow logs can be exported in CSV format for statistical process control (SPC) analysis. When integrated with chromatography data systems (CDS) such as Thermo Chromeleon or Waters Empower, the pump synchronizes run parameters and alarms, fulfilling ALCOA+ data integrity principles.

Applications

• Preparative and analytical HPLC/UHPLC solvent delivery with gradient capability via dual-pump synchronization.
• Continuous-flow synthesis reactors requiring stoichiometric reagent dosing at elevated pressures (e.g., hydrogenations, photochemical transformations).
• Calibration and reference standard delivery in metrology labs performing gravimetric flow verification per ISO 4064-2.
• Teaching laboratories demonstrating fluid dynamics, pump efficiency, and pressure–flow relationships under controlled conditions.
• Process analytical technology (PAT) deployments where real-time flow consistency directly impacts reaction yield and impurity profile.
• Environmental testing setups involving leachate extraction or column breakthrough studies under sustained backpressure.

FAQ

What materials are available for wetted components, and how do they affect chemical compatibility?
The Series III offers two standard fluid path options: 316L stainless steel for high-pressure inert applications and PEEK for superior resistance to strong acids, bases, and halogenated solvents. Material selection must align with both solvent aggressiveness and temperature requirements per ASTM D543 guidelines.
Can the pump be integrated into a gradient system?
Yes—two or more Series III units can be synchronized via external TTL triggers or RS232 commands to generate binary or ternary gradients with precise timing and flow coordination.
Is the pressure sensor user-calibratable?
No—pressure transducers are factory-calibrated and sealed. Calibration certificates traceable to NIST standards are provided with each unit and may be re-verified annually using dead-weight testers compliant with ISO/IEC 17025.
Does the pump support regulatory-compliant audit trails?
When operated with validated host software that captures all parameter changes, alarm events, and runtime logs—including timestamps and operator IDs—the system satisfies FDA 21 CFR Part 11 electronic record requirements.
What maintenance intervals are recommended for routine operation?
Under typical lab use (8 hrs/day, aqueous/organic mobile phases), piston seals should be inspected every 6 months and replaced annually; check valves every 12 months; and pulse damper diaphragms every 24 months—per SSI Maintenance Bulletin MB-III-2023.