DF Standard Venturi Flowmeter
The Venturi tube produces a permanent pressure loss of only about one-eighth of the differential pressure value, offering significantly lower pressure loss and substantially shorter straight-pipe run requirements compared to other standard throttling devices. It is widely used for flow measurement of fluids such as air, natural gas, coal gas, water, and steam, and complies with ISO 5167-4:2022.
Technical data
| Accuracy: | In accordance with ISO 5167-4 | Nominal Size: | Machined type: 50–350 mm; Rolled-and-welded type: 200–3,000 mm |
| Nominal Pressure: | 0.25 MPa to 10 MPa | Process Temperature: | -40°C to +500°C |
| Pressure Loss Ratio | Only one-eighth of the differential pressure value |
Features & Benefits
Minimal Permanent Pressure Loss, Energy Saving
The Venturi tube's tapered inlet and gradual diffuser recover most of the kinetic energy after throttling. Permanent pressure loss is only about one-eighth of the measured differential pressure—far lower than orifice plates or nozzles. On large-diameter, continuously running water supply, circulation, and gas systems, annual energy savings are substantial, delivering strong long-term economics.
Substantially shorter upstream and downstream straight-pipe run requirements compared to other standard throttling devices, reducing installation space requirements.
The tapered inlet conditions the flow profile so effectively that the required upstream and downstream straight runs are the shortest among all standard differential-pressure primary elements. For retrofits, underground pipe galleries, and pump stations where space is limited, the Venturi is one of the few options that maintains accuracy without long straight sections.
Smooth DP Characteristics, Stable and Reliable Operation
The streamlined contour produces a smooth, continuous DP-to-flow relationship with no sudden separation or turbulence. Output signals stay stable without wear-induced drift—highly reliable under fluctuating loads and frequent startups and shutdowns. A long-trusted choice for critical power plant and water utility lines.
Universal Media Compatibility, Handles Dirty and Two-Phase Flow
The smooth, gradual geometry with no sharp edges resists fouling and particle buildup. Suitable for liquids, gases, and steam, as well as dusty gases, particle-laden slurries, and two-phase flow—proven on coke oven gas, blast furnace gas, and wastewater services where conventional throttling devices struggle.
Pure Mechanical Structure, Maintenance-Free, Long Life
An all-mechanical design with no rotating parts and no wear components, simple and rugged. Once installed and commissioned, it requires essentially no maintenance, with a design life of decades—delivering the lowest total cost of ownership over the full service life.
Applications
Power
Primary/secondary air flow monitoring in boilers (large pipe diameters, DN200–3,000)
Metallurgy
Cold blast flow for blast furnace hot stoves
Environmental Protection
Continuous emission monitoring systems (CEMS) for flue gas
Chemical
Large-diameter process gas metering
Case Studies
Liaoning Baolai Chemical Co., Ltd. – Light Hydrocarbon Comprehensive Utilization Project, Ethylene Plant
Liaoning Baolai Chemical's light hydrocarbon comprehensive utilization project is a large-scale ethylene complex. 31 DF series Venturi tubes serve large-bore lines for cracking gas, quench water, circulating water and steam across the ethylene plant, offering high-pressure and high-temperature capability with low permanent pressure loss, supporting long-cycle stable operation.
Huayang Hengsheng Group – Jingzhou 706/707/901 Units & Shandong Carbon-Black Water Venturi Retrofit
Huayang Hengsheng is a leading domestic coal-chemical enterprise. 29 DF series Venturi tubes serve the Jingzhou 706/707/901 units and the Dezhou carbon-black water Venturi retrofit, measuring black water, grey water, process gas and steam; wear-resistant construction handles solids-laden media, supporting continuous gasifier operation.
Zhongke Hefei Coal Gasification Technology Co., Ltd. – Xinjiang Yihua 3×40,000 Nm³/h Circulating Fluidized Bed Oxygen-Enriched Gasification EPC
Zhongke Hefei Coal Gasification is the EPC contractor for Xinjiang Yihua's 3×40,000 Nm³/h circulating fluidized bed oxygen-enriched gasification unit. 6 DF series Venturi tubes meter oxygen-enriched air, syngas and gasification agent in the gasification section, with reliable construction supporting gasifier load regulation and oxygen consumption accounting.
