The Great Wall SHB-IV Dual-A Circulating Water Vacuum Pump

Overview

The Great Wall SHB-IV Dual-A Circulating Water Vacuum Pump is an oil-free, water-cooled vacuum source engineered for stable, low-maintenance operation in general laboratory applications requiring moderate vacuum levels. It operates on the principle of water-ring vacuum generation: rotating impeller motion induces a partial vacuum within the pump chamber by accelerating and ejecting water to form a dynamic liquid seal, enabling continuous gas removal from connected apparatus. Designed specifically for ambient-temperature circulating water systems (6–25 °C), it achieves a maximum vacuum level of 0.0947–0.098 MPa (equivalent to ~53–30 mbar absolute pressure), making it suitable for rotary evaporation, vacuum filtration, distillation, and aspiration tasks where deep vacuum is not required but operational reliability and chemical compatibility are critical.

Key Features

• Four independent vacuum ports with individual analog vacuum gauges — enables simultaneous or selective vacuum application across multiple instruments or reaction setups without cross-contamination or pressure interference.
• Integrated fluid silencer — reduces turbulence and dissolved gas release in circulating water, improving vacuum stability and lowering operational noise to ≤55 dB(A) under standard conditions.
• Corrosion-resistant wetted components — stainless steel impeller and housing internals ensure long-term compatibility with mildly acidic, alkaline, or organic solvent vapors commonly encountered during evaporation or extraction procedures.
• Check valve assembly on each suction line — prevents backflow of reservoir water into sensitive equipment (e.g., rotary evaporators or vacuum ovens) upon shutdown, eliminating risk of water ingress and associated damage.
• Modular polypropylene (PP) water reservoir — chemically inert, UV-stabilized, and rated for continuous use at temperatures up to 60 °C; includes level indicator and drain port for routine maintenance.
• Thermal overload protection and current-limiting circuitry — automatically interrupts power if motor temperature exceeds safe operating thresholds or if supply current exceeds 1.2 A nominal, complying with IEC 61000-4-5 surge immunity standards.

Sample Compatibility & Compliance

The SHB-IV Dual-A is intended for non-hazardous, non-explosive vapor environments. It is not rated for Class I, Division 1 hazardous locations per NEC/UL 60079. Its PP reservoir and stainless steel flow path meet ASTM D5229 requirements for polymeric material resistance to aqueous chemical exposure. While not certified to ISO 8573-1 for compressed air purity, its oil-free architecture eliminates hydrocarbon contamination — supporting GLP-compliant sample preparation workflows where residual lubricant interference must be avoided. The unit conforms to GB/T 26571–2011 (Chinese national standard for laboratory vacuum pumps) and meets CE marking requirements for electromagnetic compatibility (EMC Directive 2014/30/EU) and low-voltage safety (LVD Directive 2014/35/EU).

Software & Data Management

This is a manually operated, analog-control vacuum pump with no embedded microprocessor or digital interface. Vacuum monitoring is performed via four calibrated Bourdon-tube analog gauges (range: 0–0.1 MPa, accuracy ±0.005 MPa). No firmware, USB connectivity, or data logging capability is provided. For laboratories requiring audit-ready records, external pressure transducers (e.g., Validated Honeywell PX2EF series) may be integrated via 1/8″ NPT ports on each outlet line, feeding into validated SCADA or LIMS platforms compliant with FDA 21 CFR Part 11 when paired with appropriate electronic signature and change-control protocols.

Applications

• Routine rotary evaporation of solvents including ethanol, acetone, ethyl acetate, and dichloromethane under moderate vacuum.
• Vacuum-assisted gravity filtration of aqueous and organic suspensions using Buchner or Hirsch funnels.
• Gas trapping and inert atmosphere purging in Schlenk-line preps where intermittent vacuum pulses are sufficient.
• Supporting cold trap condensation in fractional distillation assemblies.
• General-purpose aspiration in cell culture hoods or chemistry fume cabinets where oil-free operation is mandated.

FAQ

What is the recommended water replacement interval for optimal vacuum performance?
Under continuous 8-hour daily use with tap water, replace reservoir water every 48–72 hours. With deionized water and ambient temperatures below 20 °C, intervals may extend to 5–7 days. Monitor gauge drift and audible cavitation onset as empirical indicators.
Can this pump be used with aggressive solvents such as concentrated nitric acid or chlorinated hydrocarbons?
No. While stainless steel internals resist mild corrosion, prolonged exposure to strong oxidizers or halogenated solvents may degrade seals and accelerate PP reservoir aging. Use only with water-miscible or low-volatility organics confirmed compatible with ASTM D5229 Class F exposure ratings.
Is the SHB-IV Dual-A suitable for vacuum oven applications?
Yes — provided the oven’s maximum operating temperature does not exceed 80 °C and the system incorporates an inline cold trap to prevent solvent vapor saturation of the water reservoir. Always verify oven manufacturer’s vacuum compatibility documentation prior to integration.
Does the pump include a built-in water chiller?
No. It relies on ambient-temperature circulating water (6–25 °C). For applications demanding stable sub-15 °C coolant, an external recirculating chiller (e.g., Huber Ministat 230) must be plumbed in series with the reservoir.
How is calibration traceability maintained for the analog vacuum gauges?
Gauges are factory-calibrated against NIST-traceable deadweight testers. Users should perform periodic verification using a reference digital manometer (e.g., Druck DPI 610) per ISO/IEC 17025 guidelines, especially after mechanical shock or extended service (>6 months).