Venturi Tubes - Classical Design
Precision differential pressure flow measurement with minimal permanent pressure loss. Daehan Instrument's venturi tubes combine 35 years of expertise with ISO 5167-4 classical design standards for superior performance and reliability.
Our Venturi Tube Product Lines
DHVT-C Series (Classical Design)
ISO 5167-4 Compliant Venturi Tubes
- Accuracy: ±0.5% to ±1.0%
- Material: 316L SS, Carbon Steel, Hastelloy
- Pressure: Up to 420 bar (6000 PSI)
- Temperature: -200°C to 600°C
- Size Range: DN50 to DN1200
β ratio: 0.30 ≤ β ≤ 0.75
Low permanent pressure loss: ~10-15%
DHVT-N Series (Venturi Nozzle)
Compact Design for High Reynolds Numbers
- Accuracy: ±0.5% to ±0.7%
- Material: 316L SS, Inconel
- Pressure: Up to 300 bar (4350 PSI)
- Temperature: -50°C to 550°C
- Size Range: DN25 to DN600
Steam Flow, High Velocity Gas
Power Generation, Process Control
DHVT-L Series (Low Loss Design)
Optimized for Minimal Pressure Drop
- Accuracy: ±0.7% to ±1.0%
- Pressure Loss: <5% of differential
- Material: 304/316 SS
- Pressure: Up to 150 bar (2175 PSI)
- Ideal for pumping energy conservation
Energy Savings, Extended Pump Life
Water Treatment, HVAC Systems
ISO 5167-4 Technical Excellence
Our venturi tubes are manufactured in strict accordance with ISO 5167-4:2022 classical design standards, ensuring optimal flow measurement performance with minimal permanent pressure loss.
Low Pressure Loss
Only 10-15% permanent pressure loss compared to 50-90% for orifice plates
Classical Profile
Precisely machined convergent-divergent profile per ISO 5167-4 specifications
Self-Cleaning Design
Smooth internal surfaces prevent sediment buildup and maintain accuracy
Wide Turndown Ratio
Excellent performance across wide flow ranges with stable coefficient
| Technical Parameter | ISO 5167-4 Requirement | Daehan Standard |
|---|---|---|
| Pipe Diameter Range | 100mm ≤ D ≤ 800mm | 50mm ≤ D ≤ 1200mm |
| Beta Ratio (β) | 0.30 ≤ β ≤ 0.75 | 0.40 ≤ β ≤ 0.70 (optimized) |
| Reynolds Number | ReD ≥ 200,000 | 150,000 ≤ ReD ≤ 10⁷ |
| Convergent Angle | 21° ± 1° | 21° ± 0.5° |
| Divergent Angle | 7° to 15° | 7° ± 0.5° (standard) |
| Surface Roughness | Ra ≤ 10⁻⁴d | Ra ≤ 0.8 μm |
| Permanent Pressure Loss | 10-15% of ΔP | 8-12% of ΔP (optimized) |
Design Features & Benefits
Classical Convergent-Divergent Profile
- Smooth flow acceleration and deceleration
- Minimal flow separation and turbulence
- Predictable discharge coefficient
- Long-term stability and reliability
Energy Efficiency
- 85-90% pressure recovery
- Reduced pumping costs
- Lower lifecycle operating expenses
- Environmental sustainability
Robust Construction
- All-welded design for high pressure
- Stress-relieved construction
- Corrosion-resistant materials
- Minimal maintenance requirements
Flow Coefficient Accuracy:
Our venturi tubes achieve discharge coefficient accuracy of ±0.7% when manufactured per ISO 5167-4 standards. The coefficient remains stable across wide Reynolds number ranges, ensuring consistent measurement performance.
Installation Requirements per ISO 5167-4
| Upstream Fitting | Minimum Straight Length | Recommended Length |
|---|---|---|
| Single 90° Elbow | 5D to 20D (β dependent) | 25D |
| Two 90° Elbows (same plane) | 5D to 20D (β dependent) | 30D |
| Two 90° Elbows (different planes) | 5D to 20D (β dependent) | 40D |
| Reducer (2:1) | 5D to 20D (β dependent) | 25D |
| Full Bore Valve | 5D to 20D (β dependent) | 20D |
| Downstream Length | 3D minimum | 5D |
Note: Venturi tubes require significantly shorter straight pipe lengths compared to orifice plates, making them ideal for installations with space constraints.
Industry Applications
Water & Wastewater
- Municipal water distribution
- Wastewater treatment plants
- Irrigation systems
- Potable water monitoring
Power Generation
- Cooling water systems
- Condensate measurement
- Boiler feedwater
- Steam flow monitoring
Chemical & Process
- Clean liquid measurement
- Process cooling water
- Chemical feed systems
- Slurry applications
Why Choose Daehan Venturi Tubes?
35 Years of Excellence
Proven track record in differential pressure flow measurement
ISO Certified Manufacturing
ISO 9001:2015 & ISO 14001:2015 certified facility
KOLAS Accredited Testing
In-house flow calibration laboratory
Custom Engineering
Tailored solutions for unique flow conditions
Lifecycle Value
Low pressure loss = reduced operating costs
Global Support
Technical support in multiple languages
Technical Resources
Download our comprehensive venturi tube documentation and sizing tools
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