Overview

The average velocity tube flow sensor is a differential pressure flow sensor developed based on the principle of Pitot tube speed measurement. This sensor is used in conjunction with differential pressure transmitters, flow display integrators, and other instruments to measure the flow of liquids, gases, and steam in circular and rectangular pipelines. The average velocity flow meter can be widely used in industries such as power, chemical, petroleum, and light textile due to its low pressure loss and ease of installation and maintenance, making it particularly suitable for measuring flow in large diameter pipelines.

Working Principle

The flow velocity in a typical pipeline is uneven. To measure it accurately, the entire circular cross-section is divided into multiple annular units. The multiple pressure tapping holes of the sensor are located at the center of each unit area, and the measured pressure reflects the average flow velocity within each unit area. The positive pressure tapping holes are interconnected, and after averaging the positive pressure values within the probe, they are directed to the positive pressure joint via a positive pressure pipe. The negative pressure is directed to the negative pressure joint in a similar manner (except for the flute-shaped and rhombic types which have only one negative pressure tapping hole). The positive and negative tapping points are connected to a differential pressure transmitter, and the measured differential pressure is proportional to the square of the flow rate, thus enabling measurement of pipeline flow.

Features

1. Simple structure

2. Good stability performance

3. Simple installation and maintenance, beneficial for pipeline layout

4. Low pressure loss and energy consumption

5. Can achieve online installation

Classification

Classified by probe cross-section shape as follows:

Technical Indicators

1. Accuracy level: 0.5—2.0 grade

2. Working pressure: ≤25MPa

3. Working temperature: -20℃-500℃

4. Measurement pipe diameter: 50mm-5000mm

Model Representation Method

1. Average velocity tube type

ZLLGZ——Rhombic average velocity tube ZLLGPLB——Proba average velocity tube
ZLLGD——Flute-shaped average velocity tube ZLLGCLB——Superba average velocity tube
ZLLGSD——Double flute-shaped average velocity tube ZLLGVLB——Weiba average velocity tube
ZLLGT——Toba average velocity tube ZLLGDTB——Delta average velocity tube

2. Installation form

L1——Single end fixed threaded connection L4D——Single rod driven online installation with threaded connection
L2——Double end fixed threaded connection L4S——Double rod driven online installation with threaded connection
L3——Threaded connection with compression locking
L4DB——Single rod driven partially inserted online installation with threaded connection
L4SB——Double rod driven partially inserted online installation with threaded connection
F1——Single end fixed flange connection F3D——Single rod driven online installation with flange connection
F2——Double end fixed flange connection F3S——Double rod driven online installation with flange connection
F1B——Partially inserted flange connection
F3DB——Single rod driven partially inserted online installation with flange connection
F3SB——Double rod driven partially inserted online installation with flange connection

3. Probe nominal diameter

Diameter range: 50mm～5000mm