Positive Displacement Flow Meters
Working Principle of PD Flow Meters
Positive displacement flow meters consist of a set of chambers or compartments that are filled with the fluid. Each time the fluid flows through the meter, the chambers fill to a certain volume. Once the chamber is full, it discharges the fluid and is refilled again for the next cycle. The key here is that each cycle corresponds to a known volume of fluid. The meter counts the number of these cycles, and based on the volume of each cycle, it calculates the flow rate. This process works well because the measurement is independent of factors like pressure and temperature, which can affect other types of flow meters. For example, in a rotary piston PD meter, a rotor moves within a chamber, displacing a fixed volume of liquid with each rotation. The number of rotor rotations is then used to calculate the total flow of the liquid.
Bi-rotor Positive Displacement Flow Meter (MT-ABR)
- High accuracy up to ±0.1 %
- Strong applicability to viscosity changes.
- Good anti-interference performance and long service life.
Accuracy
Standard: ±0.5 %, Optional: ±0.2 %; ±0.1 %
Measuring Range
0.3 to 1800 m³/h
Medium Temperature Range
Standard: (-20～+100) ℃, Optional: (-20～+250) ℃
Max. Process Pressure
110 bar (1595 psi)
M Series Mechanical Positive Displacement Flow Meter
- ±0.2 % accuracy
- Strong applicability to viscosity changes.
- Good for fuel delivery trucks and tankers.
Accuracy
±0.2 %
Measuring Range
25 to 3000 L/Min
Medium Temperature Range
-20～+250 ℃
Max. Process Pressure
25 bar (350 psi)
Low Flow Positive Displacement Gear Flow Meter MT-GF
- Designed for low flow liquids from 0.6 L/H.
- 150:1 wide turndown ratio
- Capable of measuring highly corrosive medium.
Accuracy
±0.5 %
Measuring Range
0.6 to 2000 l/h
Medium Temperature Range
Standard: (-40～+80) ℃, Optional: (-40～+200) ℃
Max. Process Pressure
Standard: 100 bar, Optional: 400 bar
Birotor PD Flowmeter with Mechanical Counter (MT-ABRM)
- High accuracy up to ±0.1 %
- Strong applicability to viscosity changes.
- Good anti-interference performance and long service life.
Accuracy
Standard: ±0.5 %, Optional: ±0.2 %; ±0.1 %
Measuring Range
0.3 to 1800 m³/h
Medium Temperature Range
Standard: (-20～+100) ℃, Optional: (-20～+250) ℃
Max. Process Pressure
110 bar (1595 psi)
Oval Gear PD Flow Meter MT-LC
- Optimized for higher viscosity liquid measurement.
- Not sensitive to the viscosity change.
- Simple installation without requiring straight pipe runs.
Accuracy
Standard: ±0.5 %, Optional: ±0.2 %
Measuring Range
0.05 to 340 m³/h
Medium Temperature Range
Standard: (-20～+60) ℃ ， Optional: (-41～+60) ℃
Max. Process Pressure
63 bar
Air Eliminators / Strainers (MT-LPGX)
- Removes entrained air or gas from the fluid.
- Protecting all downstream system components.
- Used in applications where precise liquid-only measurement is critical.
Nominal Diameter Range
DN 15 to 800 (½” to 32″)
Medium Temperature Range
Standard: (-20～+100) ℃ ， Optional: (-20～+250) ℃
Max. Process Pressure
64 bar (928.24 psi)
Mesh Number
10 to 40 (Others on request)
Advantages of Positive Displacement Flow Meters
- High Accuracy: PD flow meters are highly accurate, especially for low-flow applications. The direct volumetric measurement method is less influenced by external factors such as temperature and pressure.
- Wide Range of Liquids: PD meters can measure a wide variety of liquids, including low and high viscosity fluids.
- No Calibration for Viscosity: Unlike other types of flow meters, PD flow meters do not require recalibration when used with different fluids, as the measurement is based on volume displacement.
- Simple Design: The design of PD flow meters is relatively simple, which makes them easy to maintain and repair.
- Good for Batch Measurements: PD meters are ideal for batch processing, where precise measurements of fluid volumes are needed.
Applications of Positive Displacement Flow Meters
PD flow meters are used in various industries that require precise flow measurement. Some common applications include:
- Oil and Gas Industry:
- PD meters are widely used for measuring crude oil, refined fuels, and lubricants. Their accuracy in measuring flow rates in pipelines and for custody transfer applications makes them ideal for this industry.
- Chemical and Pharmaceutical Industries:
- Positive Displacement flow meters are used for dosing and batching processes in chemical manufacturing and pharmaceutical production. They ensure accurate volume measurement and help maintain product quality.
- Food and Beverage Industry:
- The food and beverage industry uses PD flow meters for measuring ingredients, flavorings, and other liquids. The high accuracy and hygienic design of these meters make them suitable for food processing applications.
- Water Treatment:
- PD meters are used to monitor and measure the flow of water and other liquids in treatment plants, ensuring accurate dosing of chemicals and monitoring of effluent discharges.
- Fuel Dispensing:
- PD flow meters are commonly used in fuel dispensers at gas stations, ensuring accurate measurement of fuel dispensed to customers.
- HVAC Systems:
- Positive displacement flow meters are used in HVAC systems to monitor compressed air systems and ensure proper airflow to equipment.