The Great Wall SHB-IIIG Desktop Circulating Water Vacuum Pump

Overview

The Great Wall SHB-IIIG Desktop Circulating Water Vacuum Pump is an oil-free, water-sealed vacuum source engineered for precision and reliability in academic, pharmaceutical, and industrial laboratory environments. It operates on the principle of water-ring vacuum generation: rotating impeller motion induces centrifugal force to form a liquid ring inside the pump chamber, creating sealed cavities that alternately expand (drawing in gas through the inlet) and contract (expelling gas through the exhaust). This mechanism enables stable vacuum generation without lubricating oils—eliminating risk of hydrocarbon contamination and simplifying maintenance. Designed specifically for integration with rotary evaporators, distillation setups, vacuum filtration manifolds, and cold traps, the SHB-IIIG delivers consistent performance across evaporation, concentration, solvent recovery, and degassing applications. Its compact footprint and lightweight construction (9.5 kg) support flexible benchtop deployment, while its dual independent suction ports allow simultaneous operation of two instruments—or coordinated use with a circulating chiller for enhanced thermal management.

Key Features

• Dual independent vacuum ports with individual pressure gauges—enabling isolated or parallel operation without cross-contamination or pressure interference.
• Corrosion-resistant wetted materials: 304 stainless steel impeller and shaft; fluororubber (FKM) dynamic seals between motor housing and shaft—providing compatibility with mild organic solvents and acidic vapors.
• Integrated fluid silencer reduces turbulence-induced noise by minimizing gas entrainment and air–water interface friction within the water circuit, resulting in lower operational sound pressure levels (<62 dB(A) typical).
• Non-return valve assembly installed in internal gas pathways prevents backflow of condensate or cooling water into connected apparatus—critical for protecting sensitive glassware and vacuum-sensitive instrumentation.
• Modular water tank design (15 L capacity) with easy-access drain and fill ports facilitates routine water replacement to maintain optimal vapor pressure and vacuum stability; recommended water change interval: every 4–8 hours under continuous load at ambient >25 °C.
• Thermally stable architecture: maximum operating water temperature limited to 35 °C; elevated water temperature directly affects saturated vapor pressure—and thus ultimate attainable vacuum—making active cooling or periodic water refreshment essential for reproducible sub-20 mbar performance.

Sample Compatibility & Compliance

The SHB-IIIG is compatible with standard laboratory glassware interfaces (e.g., 10/15/19/24 standard taper joints) and commonly used vacuum-rated tubing (ID 6–10 mm). As a water-based vacuum source, it is unsuitable for applications involving water-reactive compounds (e.g., alkali metals, acid chlorides), high-boiling-point solvents with low vapor pressure (e.g., DMSO, glycerol), or processes requiring deep vacuum (<10 mbar). While not certified to ISO 9001 or CE for standalone medical device use, the pump conforms to IEC 61000-6-3 (EMC emission limits) and IEC 61000-6-2 (immunity requirements). Its IP20 enclosure rating indicates protection against solid objects ≥12.5 mm but no moisture resistance—thus installation in dry, well-ventilated lab spaces is mandatory. For GLP/GMP-regulated workflows, users must validate vacuum stability, water quality control procedures, and logbook-based maintenance records per internal SOPs.

Software & Data Management

The SHB-IIIG is a manually operated, analog-control vacuum pump with no embedded microprocessor, digital display, or data output interface. All operational parameters—including vacuum level, flow rate, and temperature—are monitored externally via mechanical gauges and user observation. Consequently, it does not support USB/RS-232 connectivity, remote monitoring, or electronic audit trails. However, its simplicity ensures compliance with FDA 21 CFR Part 11 when deployed in manual, non-automated workflows where vacuum status is recorded manually in bound lab notebooks or validated electronic lab notebooks (ELNs). For laboratories requiring traceable vacuum logging, integration with external pressure transducers (e.g., capacitance manometers) and DAQ systems is feasible via standard NPT or Swagelok fittings on the exhaust or intake manifolds.

Applications

• Vacuum-assisted rotary evaporation of heat-sensitive organic compounds (e.g., terpenes, alkaloids, peptides)
• Short-path distillation under reduced pressure for purification of high-molecular-weight lipids and polymers
• Gas-phase extraction and inert atmosphere purging prior to Schlenk-line manipulations
• Membrane filtration of aqueous and mildly polar solutions (e.g., buffer exchange, nanoparticle harvesting)
• Evacuation of desiccators and vacuum ovens for moisture-sensitive sample storage
• Support function in multi-stage vacuum systems—serving as primary roughing pump upstream of diffusion or turbomolecular pumps

FAQ

What is the recommended water type for optimal vacuum performance?
Deionized or distilled water is strongly recommended to prevent scale buildup and maintain consistent vapor pressure. Tap water may be used temporarily but requires more frequent replacement due to dissolved mineral content.
Can the SHB-IIIG be used continuously for 24 hours?
Yes—provided ambient temperature remains ≤30 °C, water is refreshed every 6–8 hours, and the pump is placed in a well-ventilated area to dissipate motor heat. Continuous operation beyond 12 hours without water exchange will degrade vacuum stability.
Is the pump compatible with aggressive solvents like chloroform or acetone?
The wetted components (PP, 304 SS, FKM) offer moderate resistance—but prolonged exposure to halogenated solvents may swell PP parts over time. Use only with adequate condenser trapping and verify material compatibility per ASTM D471 guidelines.
How does ambient temperature affect ultimate vacuum?
Water’s saturated vapor pressure rises exponentially with temperature: at 20 °C it is ~2.3 kPa (17.5 torr); at 30 °C it increases to ~4.2 kPa (31.8 torr). Since ultimate vacuum cannot exceed this value, maintaining low water temperature is essential for achieving ≤20 mbar performance.
Does the SHB-IIIG require routine oil changes?
No—this is an oil-free, water-sealed pump. Maintenance consists solely of periodic water replacement, inspection of seals, and cleaning of the water tank and inlet strainer.