| Medium Temperature | -20°C ~ 60°C |
| Nominal Pressure | 1.6 MPa; 2.5 MPa; 4.0 MPa; 6.3 MPa |
| Diameter (DN) | DN25 – DN200 (customizable for special requirements) |
| Accuracy Class | ±0.5%; ±1.0% |
| Flow Range | 0.5 ~ 3000 m³/h |
| Protection Grade | IP65 (default); IP68 (customizable) |
| Power Supply Voltage | 24V, 220V, 3.6V, lithium battery power supply (optional) |
| Output Signal | Pulse signal output, 4–20 mA current output, RS485 communication, GPRS remote transmission communication |
| Installation Type | Flanged, Threaded |
Roots Flow Meter
Roots flowmeter
Detailed Description
Principle of operation
The Roots flowmeter is mainly composed of a housing, conjugate rotors, and an intelligent flow totalizer. Under the effect of the pressure difference between the inlet and outlet of the flowing gas (P_in > P_out), a pair of conjugate rotors installed in the metering chamber maintain the correct relative position through precision-machined timing gears. Optimal operating clearances are maintained between the rotors, between the rotors and the housing, and between the rotors and the side plates, achieving continuous, non-contact sealing. With each complete rotation of the rotors, the meter delivers a volume of gas equal to four times the effective volume of the metering chamber. The rotational speed of the rotors is transmitted to the intelligent flow totalizer via a magnetically sealed coupling device and a reduction gear mechanism, thereby displaying the cumulative volume of gas output.
Flow Range
| Model / Spec | Nominal Diameter DN (mm) | Upper Flow Limit (m³/h) | Starting Flow (m³/h) | Pressure Loss at Qmax (Pa) | Nominal Pressure (MPa) | Accuracy (%) | Instrument Coefficient | Rangeability | Material |
|---|---|---|---|---|---|---|---|---|---|
| NNLLQ-20-D | 25 | 20 | 0.05 | 100 | 0.6, 1.6 | 1.0, 1.5 | 7633.37 | 20:1 | Aluminum alloy |
| NNLLQ-30-D | 40 | 30 | 0.07 | 100 | 0.6, 1.6 | 1.0, 1.5 | 4694.65 | 30:1 | Aluminum alloy |
| NNLLQ-40-D | 40 | 40 | 0.07 | 140 | 0.6, 1.6 | 1.0, 1.5 | 3892.31 | 40:1 | Aluminum alloy |
| NNLLQ-60-D | 50 | 60 | 0.10 | 100 | 0.6, 1.6 | 1.0, 1.5 | 1584.24 | 65:1 | Aluminum alloy |
| NNLLQ-80-D | 50 | 80 | 0.10 | 140 | 0.6, 1.6 | 1.0, 1.5 | 1584.24 | 70:1 | Aluminum alloy |
| NNLLQ-100-D | 80 | 100 | 0.10 | 110 | 0.6, 1.6 | 1.0, 1.5 | 987.581 | 70:1 | Aluminum alloy |
| NNLLQ-150-D | 80 | 150 | 0.12 | 150 | 0.6, 1.6 | 1.0, 1.5 | 730.785 | 120:1 | Aluminum alloy |
| NNLLQ-200-D | 80 | 200 | 0.15 | 180 | 0.6, 1.6 | 1.0, 1.5 | 479.837 | 70:1 | Aluminum alloy |
| NNLLQ-250-D | 100 | 250 | 0.11 | 180 | 0.6, 1.6 | 1.0, 1.5 | 306.804 | 80:1 | Aluminum alloy |
| NNLLQ-300-D | 100 | 300 | 0.11 | 130 | 0.6, 1.6 | 1.0, 1.5 | 306.804 | 110:1 | Aluminum alloy |
| NNLLQ-450-D | 100 | 450 | 0.10 | 200 | 0.6, 1.6 | 1.0, 1.5 | 231.350 | 110:1 | Aluminum alloy |
| NNLLQ-650-D | 150 | 650 | 0.65 | 350 | 0.6, 1.6 | 1.0, 1.5 | 86.7083 | 80:1 | Aluminum, cast iron |
| NNLLQ-1000-D | 150 | 1000 | 0.76 | 450 | 0.6, 1.6 | 1.0, 1.5 | 61.8990 | 90:1 | Aluminum, cast iron |
| NNLLQ-1600-D | 200 | 1600 | 1.15 | 500 | 0.6, 1.6 | 1.0, 1.5 | 50.2425 | 53:1 | Aluminum, cast iron |
Field installation example
