COLO.Science · Technical Specification
OVST Series
Laboratory Overhead Stirrer · Analog & Digital Models
The OVST series (A / D) overhead stirrer is driven by a brushless motor for continuous operation. It is suitable for mixing low to high viscosity liquids, homogenization, and dispersion in laboratory or pilot plant environments. The system integrates a plastic housing, a stainless steel chuck (0.5–10 mm bore), and precise speed regulation – available in analog scale (OVSTA20) or digital touch-screen (OVSTD20, OVSTD40, OVSTD40C) control. A laboratory graduated glass beaker (600 ml), a four‑blade propeller, stand and clamp are included as standard.
Overhead Stirrer
100–2500 rpm
Max 40 L capacity
Brushless Motor
Digital Timer
Up to 1250W
A: analog | D: digital
OVSTA20 · Analog scale speed controller
OVSTD20 · Digital touch control display (also OVSTD40/40C)
Models
OVSTA20 · OVSTD20 · OVSTD40 · OVSTD40C
Address (HQ)
Polje ob Sotli 4
SI-3255, Slovenia
SI-3255, Slovenia
Contact
sales@colo.si
+386 70 713 437
+386 70 713 437
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OVST · Overhead Stirrer
Document ID: COL-TEC-OVST-EN
Version: Print Edition · V1.0
Technical datasheet · Non-binding · Controlled document
Version: Print Edition · V1.0
Technical datasheet · Non-binding · Controlled document
OVSTA20 / OVSTD20 / OVSTD40 / OVSTD40C · technical specificationoverhead stirrer for laboratory mixing
Brushless motor
Stainless steel chuck
Continuous operation
Up to 2500 rpm
High torque
— Ideal for emulsions, suspensions, high‑viscosity mixing & mud mixing
📊 Comparative specifications · OVST Series
| Parameter | OVSTA20 (analog) | OVSTD20 (digital) |
|---|---|---|
| Function / Max. Volume (L) | 20 | 20 |
| Speed range (rpm) | 100 – 2500 (stepless) | |
| Working time | Continuous | |
| Minimum revolution (rpm) | 100 | |
| Exterior | Plastic shell | |
| Driving mode | Brushless motor | |
| Motor power (W) | 1000 | 1000 |
| Controller / Continuous operation | Yes | |
| Setting mode | Analog Scale | Digital |
| Speed display mode | Analog Scale | Digital |
| Timer | No | Yes |
| Max Viscosity (mPas) | 10000 | 10000 |
| Exterior size (W*L*H)(mm) | 115×95×400 | |
| Packing size (W*L*H)(mm) | 400×250×410 | |
| Plate size (mm) | 200×300 | |
| Plate load | 50KG | |
| Power supply (50/60Hz) | 100～240V | |
| NW/GW (kg) | 7/8 | 7/8 |
📦 Extended options · OVSTD40 & OVSTD40C
| Parameter | OVSTD40 (digital) | OVSTD40C (digital) |
|---|---|---|
| Function / Max. Volume (L) | 40 | 40 |
| Speed range (rpm) | 100 – 2500 | |
| Working time | Continuous | |
| Motor power (W) | 1200 | 1250 |
| Max Viscosity (mPas) | 15000 | 50000 |
| Timer | Yes | |
| Setting mode | Digital | |
| Speed display mode | Digital | |
| NW/GW (kg) | 7.5/8.5 | 8/9 |
* All digital models include timer function, LCD display, and brushless motor. OVSTD40C offers higher torque for extremely viscous applications (e.g., mud mixing). All units include stainless steel chuck (0.5–10 mm bore), four‑blade propeller, stand, clamp, and 600 ml graduated beaker.
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⚙️ Working principle & key features
Overhead stirring principle
Mechanical mixing: The brushless motor drives a propeller to provide uniform mixing across the entire vessel.
Three operating modes (digital models): Positive rotation, reverse rotation, and alternating positive/negative for optimized mixing patterns.
Continuous operation: Designed for long‑duration mixing without overheating.
High torque: OVSTD40C delivers 1250W power handling up to 50,000 mPas viscosity (ideal for mud, pastes, heavy slurries).
Superior drive & safety design
Brushless motor: High efficiency, low noise, maintenance‑free, and suitable for continuous duty.
Plastic housing: Lightweight, corrosion‑resistant, and impact‑resistant.
Stainless steel chuck: Clamping range 0.5–10 mm, holds various impellers and shafts.
Digital vs analog control: Digital models (OVSTD20/40/40C) feature LCD display, timer, and three rotation modes; analog model (OVSTA20) uses simple scale control.
Materials & laboratory suitability
Wetted parts: Stainless steel propeller and chuck – excellent corrosion resistance.
Viscosity range: Suitable for low, medium, and high viscosity liquids (up to 50,000 mPas with OVSTD40C).
Pilot/Lab scale: Ideal for R&D, QC labs, small‑batch production, and scale‑up studies.
Feature comparison: analog vs digital experience
| OVSTA20 | Analog scale speed knob, no timer, simple and budget‑friendly. |
| OVSTD20 / 40 / 40C | Digital LCD display, timer (0–999 min), three rotation modes (forward, reverse, alternating). |
🧪 Typical applications
- Emulsion preparation (o/w, w/o)
- Nanoparticle dispersion
- Cell disruption & homogenization
- Pigment & coating mixing
- Pharmaceutical creams & ointments
- Food emulsions (mayonnaise, sauces)
- Chemical & polymer processing
- Cosmetic lotions & gels
- Mud mixing & heavy slurries (OVSTD40C)
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🖼️ Product visuals & dimensions
Standard propeller & chuck
| Component | Specification |
|---|---|
| Propeller type | Four‑blade stainless steel |
| Chuck bore diameter | 0.5 – 10 mm |
| Max propeller speed | 2500 rpm |
| Shaft length | 400 mm (approx.) |
Technical notes & performance
Plate dimensions: 200×300 mm, load capacity 50 kg.
Exterior dimensions (W×L×H): 115×95×400 mm.
Power supply: 100–240V, 50/60Hz, continuous operation.
Mounting: Heavy‑duty stainless steel support stand and clamp included.
Max capacity40 L (water)
Speed range100 – 2500 rpm
Motor power1000–1250W
Max viscosity50,000 mPas
* Performance depends on propeller type, vessel shape, and sample viscosity. For extremely high‑viscosity samples, use OVSTD40C model.
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📦 Ordering information & standard delivery scope
| Model | Order code | Control type | Max viscosity (mPas) |
|---|---|---|---|
| OVSTA20 | OVSTA-20 | Analog scale | 10000 |
| OVSTD20 | OVSTD-20 | Digital LCD + Timer | 10000 |
| OVSTD40 | OVSTD-40 | Digital LCD + Timer | 15000 |
| OVSTD40C | OVSTD-40C | Digital LCD + Timer | 50000 |
Standard accessories (included)
- Stainless steel four‑blade propeller
- Heavy‑duty support stand + clamp
- Laboratory graduated glass beaker (600 ml)
- Operation manual & calibration certificate
Optional accessories & upgrades
- Additional propeller types (anchor, turbine, paddle)
- Flow chamber for inline recirculation
- Temperature probe adapter
- Replacement chuck and shaft seal kit
- Custom vessel stands
Manufacturer & support
COLO.Science d.o.o.
Polje ob Sotli 4, SI-3255, Slovenia
Configuration advice: specify required sample volume, viscosity range, and desired mixing pattern. OVSTD40C recommended for high‑viscosity applications (e.g., mud, pastes). Digital models offer timer and three rotation modes.
Quick contact
COLO.Science · overhead stirrer support
Request a quote or application consultation
Tell us about your mixing task: viscosity, batch volume, target homogeneity, and preferred model (analog/digital). Our technical sales team will respond with detailed configuration and pricing.
Manufacturer & binding specification notice:
The information contained in this document reflects typical product parameters based on the OVST series. COLO.Science reserves the right to improve design and specifications without prior notice. For tender, procurement, and quality assurance, the only valid technical specification is the official COLO quotation accompanied by engineering-approved datasheet.
OVST series stirrers are designed for laboratory and pilot applications. Always follow safety instructions, use appropriate grounding, and wear PPE during operation.
The information contained in this document reflects typical product parameters based on the OVST series. COLO.Science reserves the right to improve design and specifications without prior notice. For tender, procurement, and quality assurance, the only valid technical specification is the official COLO quotation accompanied by engineering-approved datasheet.
OVST series stirrers are designed for laboratory and pilot applications. Always follow safety instructions, use appropriate grounding, and wear PPE during operation.
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