Special Throttling Device Types and Selection

Product Description

1. Airfoil-Type Airflow Measurement Device
The airfoil airflow measurement device is currently the most widely used flow measurement device in the domestic power industry for both primary and secondary air volume measurement. Compared with other airflow measuring devices, it has the following advantages:
a. With its unique airfoil profile, it can generate a large differential pressure, ensuring stable measurement.
b. Using a dual-airfoil or multi-airfoil structure, the device itself is short in length and requires shorter upstream and downstream straight pipe sections.
c. Pressure loss is small, not exceeding 14% of the differential pressure value.
d. The flow is uniform and stable, with a certain rectifying effect on the fluid.
e. Easy installation and maintenance.
f. High accuracy, with an error not exceeding 2% within the range of 30–100% of rated flow.

• Model: LGJT-A (flange connection), LGJT-B (welded)

• Pressure tapping method: Special tapping

• Applicable pressure: ≤1.6 MPa

• Applicable pipe diameter: ≥300 mm

• Component standard: Industry standard

• Structural form: (as shown in right figure)

2. Dual Venturi Tube and Insertion-Type Low-Pressure-Loss Flowmeter
This device is suitable for flow measurement in various rectangular or circular pipelines. It is characterized by extremely low permanent pressure loss, low cost, and shorter required straight pipe sections. It is especially suitable for large-diameter, high-flow measurements.

• Model: LGST, LGFT

• Pressure tapping method: Special tapping

• Applicable pressure: ≤6.4 MPa

• Applicable pipe diameter: 360–3000 mm

• Component standard: Industry standard

• Structural form: (as shown in left figure)

3. Averaging Flowmeter (Annubar Flowmeter)
This device is suitable for flow measurement in various rectangular or circular pipelines. It has extremely low permanent pressure loss, low cost, and requires shorter straight pipe sections. It is widely used for large-diameter, high-flow measurements, particularly in air volume measurement.

• Model: LGZT

• Pressure tapping method: Special tapping

• Applicable pressure: 0.01–6.4 MPa

• Applicable pipe diameter: 25–3000 mm

• Component standard: Industry standard

• Structural form: (round or diamond shape, as shown in left figure)

4. 1/4 Circle Orifice Plate, Conical-Entrance Orifice Plate, and Dual Orifice Plate
For conditions where the pipeline Reynolds number is very low or the medium has high viscosity, it is difficult to achieve accurate measurement with standard orifice plates or nozzles. These devices are specifically designed for such applications.

• Model: LGEH, LGEF, LGRH, LGYH

• Pressure tapping method: Ring chamber tapping, drilled tapping, flange tapping (D≥40)

• Applicable pressure: ≤1.6 MPa

• Applicable pipe diameter: 25–400 mm

• Component standard: Industry standard

• Structural form: (as shown in left figure)

5. Segmental Orifice Plate and Eccentric Orifice Plate
These orifice plates are suitable for flow measurement of dirty media. They allow media containing sediment or suspended solids to pass through more easily, preventing accumulation at the front end of the orifice plate, which could otherwise affect measurement accuracy.

• Model: LGQZ, LGQF, LGQJ

• Pressure tapping method: Drilled tapping, flange tapping, radial tapping

• Applicable pressure: ≤16.0 MPa

• Applicable pipe diameter: 50–2000 mm

• Component standard: Industry standard

• Structural form: (as shown in left figure)

6. Integral Small Orifice Plate and Built-In Small Orifice Plate
Small orifice plates are suitable for flow measurement in pipelines with inner diameters less than 50 mm.

• Model: LGMZ, LGNF

• Pressure tapping method: Corner tapping, flange tapping

• Applicable pressure: ≤16.0 MPa

• Applicable pipe diameter: 15–50 mm

• Component standard: Industry standard

• Structural form: (as shown in left figure)

7. High-Pressure Lens Orifice Plate
High-pressure lens orifice plates are suitable for flow measurement in conditions where the pressure exceeds 20 MPa. They are commonly used in high-pressure applications in chemical and refining industries.

• Model: LGGH

• Pressure tapping method: Corner tapping

• Applicable pressure: ≥20 MPa

• Applicable pipe diameter: 15–150 mm

• Component standard: Industry standard