SSI LS CLASS Single-Head High-Pressure Constant Flow Pump
| Brand | SSI |
|---|---|
| Origin | Imported |
| Model | LS CLASS |
| Flow Rate | 10 mL/min |
| Maximum Pressure | 6,000 psi |
| Flow Accuracy | <2% (at ≥0.20 mL/min, 20% IPA/water, 1,000 psi) |
| Pulsation | ≤2% (1 mL/min, 1,000 psi, with pulse dampener) |
| Flow Precision | 0.2% RSD |
| Fluid Path Materials | Stainless Steel, PEEK, optional Titanium, Sapphire, Ruby, UHMWPE, PTFE |
| Dimensions | 16.5 cm H × 17.8 cm W × 40.6 cm D |
| Weight | 6.9 kg |
| Power Supply | 100–240 VAC ±10%, 50–60 Hz |
| Control Interfaces | RS-232, Micro USB 2.0, Analog (0–10 V / 4–20 mA), Front Panel Keypad |
Overview
The SSI LS CLASS Single-Head High-Pressure Constant Flow Pump is a precision-engineered positive displacement piston pump designed for demanding liquid delivery applications in analytical and preparative chromatography. Based on a robust single-piston architecture driven by micro-stepping motor technology and an optimized cam profile, the LS CLASS delivers exceptional flow stability and minimal pulsation—critical for high-resolution HPLC, semi-preparative LC, and bio-compatible separations where baseline integrity and retention time reproducibility are paramount. Its operation adheres to fundamental principles of volumetric displacement: each piston stroke displaces a fixed volume determined by chamber geometry and stroke length, enabling inherently accurate flow control independent of backpressure fluctuations—provided system compliance remains within operational limits. The pump supports pressure-rated operation up to 6,000 psi (414 bar) with stainless steel or titanium fluidic components, while PEEK-wetted versions maintain compatibility up to 5,000 psi (345 bar), ensuring suitability for both standard reversed-phase and aggressive solvent environments.
Key Features
- Single-piston positive displacement mechanism with low-inertia cam drive for ultra-low pulsation (≤2% at 1 mL/min, 1,000 psi, with integrated pulse dampener)
- Automatic pressure compensation algorithm maintains set flow rate across variable system backpressures
- Dual-mode control: local interactive keypad with real-time status display + full remote operation via RS-232 and Micro USB 2.0 interfaces
- Integrated prime/purge valve for rapid solvent exchange and air removal without external tools
- Jacketed pump head option available for temperature-sensitive applications requiring thermal stabilization of mobile phase
- Modular fluid path construction using chemically inert, USP Class VI-compliant materials—including 316 stainless steel, PEEK, titanium, sapphire, ruby, UHMWPE, and PTFE
- 0.2% relative standard deviation (RSD) flow precision under steady-state conditions, validated per ISO 5725-2 guidelines
Sample Compatibility & Compliance
The LS CLASS accommodates a broad range of solvents—from aqueous buffers and acetonitrile to aggressive acids (e.g., 0.1% TFA) and bases (e.g., 0.1% NaOH)—when configured with appropriate wetted materials. Standard configurations meet ASTM F2028 requirements for polymer biocompatibility when PEEK or titanium is selected. All electrical subsystems comply with IEC 61010-1:2010 for laboratory equipment safety. Firmware supports audit-trail-enabled operation compatible with GLP and GMP environments; data logging timestamps, parameter changes, and error events are retained internally and exportable via serial interface for FDA 21 CFR Part 11–aligned recordkeeping when paired with validated host software.
Software & Data Management
Native communication protocols support ASCII command sets over RS-232 and USB CDC class emulation, enabling seamless integration with third-party chromatography data systems (CDS), custom LabVIEW applications, or Python-based automation frameworks. Real-time telemetry—including actual flow rate, measured pressure, motor load, and temperature (if jacketed head installed)—is continuously reportable at user-defined intervals. Internal non-volatile memory stores up to 1,000 event logs with ISO 8601 timestamps. Optional SSI PumpControl Suite (v3.2+) provides graphical configuration, method scheduling, calibration curve management, and electronic signature-capable audit trails compliant with Annex 11 and ALCOA+ data integrity principles.
Applications
- Isocratic and gradient HPLC systems requiring stable flow at pressures up to 6,000 psi
- Semi-preparative purification workflows with 10–40 mL/min flow rates and scalable column diameters
- Mobile phase metering in multi-solvent blending manifolds for method development
- Controlled reagent delivery in flow chemistry reactors and electrochemical cells
- Calibration standard delivery in gravimetric or conductivity-based flow verification setups
- Long-duration stability testing under GLP conditions where drift monitoring and traceable calibration are required
FAQ
What is the minimum programmable flow rate for the LS CLASS 10 mL/min model?
The LS CLASS supports flow programming from 0.000 mL/min upward, with resolution of 0.001 mL/min for the 10 mL/min version.
Can the pump operate continuously at 6,000 psi with PEEK fluidic components?
No—PEEK-wetted configurations are rated to 5,000 psi maximum. Full 6,000 psi operation requires stainless steel or titanium fluid paths.
Is analog input/output supported for PLC integration?
Yes: 0–10 VDC input for flow setpoint modulation and 4–20 mA output for real-time pressure feedback are standard.
How often does the pump require recalibration per ISO/IEC 17025 recommendations?
Annual calibration is recommended; however, users may perform intermediate verification using NIST-traceable flow meters at defined operating points (e.g., 1, 5, and 10 mL/min at 1,000 psi).
Does the LS CLASS support gradient formation natively?
No—the LS CLASS is a single-channel constant-flow pump. Gradient capability requires external low-dead-volume proportioning valves or a second synchronized LS CLASS unit in dual-pump configuration.
