Venturi Tube

High Pressure Recovery and Low Straight Pipe Requirements

Venturi tubes are reliable, easy-to-use, and low-maintenance flow measurement elements.
They are particularly suitable for measuring clean liquids and gases.

The greatest advantage of a Venturi tube over other differential pressure flowmeters is its ability to provide high pressure recovery and require shorter upstream and downstream straight pipe lengths.

On the inlet side of the tube, there is a gradually converging nozzle section where the fluid accelerates.
On the outlet side, there is a gradually diverging diffuser section.
This design enables high pressure recovery.

Flow Measurement at Low Differential Pressures

Since most of the outlet pressure is recovered,
Venturi tubes are particularly suitable for measurement in systems where low permanent pressure loss is required.

Thanks to the low pressure loss, the energy cost required to pump the fluid can be minimized.

Applications

• Power Generation

• Oil Production and Refining

• Water Treatment and Distribution

• Gas Processing and Transportation

• Chemical and Petrochemical Industries

Special Features

• Suitable for measuring liquid, gas, and steam flow

• Accuracy of up to ±0.5% can be achieved with calibration

• Repeatability: 0.1%

• Lowest permanent pressure loss among all primary flow elements

• Can be calibrated when required

Mounting Options and Specifications

Mounting Options

• Butt weld, bevelled

• Flanged

Pressure Tappings

The optimum solution depends on the application and is individually designed for each project.

Available pressure tapping types:

• Direct tap, threaded connection (NPT)

• Direct tap, flanged connection

• Annular chamber tap

• Piezometric ring

Basic Information

Sealing Faces for Flanged Versions

Venturi Tube – Bar Stock Model

The internal profile of this model is produced by machining.

Internal Profile

• As cast

• Machined

• As cast with machined upstream and convergent section

The operating limits may vary depending on the selected internal profile type.

Nominal Size

50 ... 800 mm [2 ... 31.5 in]

Beta Ratio

0.3 ... 0.75

Reynolds Number

2 × 10⁴ ... 3.2 × 10⁶

Accuracy

Within 0.7% ... 3% of the supplied discharge coefficient.

Venturi Tube – Welded Sheet Model

For small nominal sizes, the throat section can be machined from round bar stock.

Nominal Size

200 ... 1,200 mm [7.9 ... 47.2 in]

Beta Ratio

0.4 ... 0.7

Reynolds Number

4 × 10⁴ ... 1 × 10⁶

Accuracy

Within 1.5% ... 3% of the supplied discharge coefficient.