Company Profile

LC Flow Meter Systems for Bulk Hydrocarbon Transfer with Rotary Vanes

Quick Answer: Liquid Controls LC flow meter systems use rotary vane positive displacement technology to measure bulk transfer of diesel, gasoline, jet fuel, LPG, and biofuel. These meters deliver repeatable measurement from about 20 L/min to over 3000 L/min depending on model and viscosity. Send us your flow range, pipe size, and product type to match the right meter and companion instruments.

Bulk hydrocarbon transfer involves money. A small calibration drift in a 4 inch loading line can create an error of several hundred liters per day. That is why terminals and depots in Southeast Asia, the Middle East, and Latin America still specify Liquid Controls rotary vane meters for spot checks and billing runs.

Rotary Vane Technology in LC Meter Systems

A rotor with sliding vanes sits inside a measuring chamber. Liquid enters the chamber, fills the space between two vanes, and pushes the rotor. Each rotation captures a fixed volume. Pulse transmitters or mechanical registers convert the rotation into total flow. The measurement is direct. It does not depend on flow profile or Reynolds number. The meter works well with low viscosity gasoline and higher viscosity diesel blends.

Model Range and Flow Capacity

Liquid Controls offers M series meters in sizes from 1.5 inch to 6 inch. Common models include M-5, M-7, M-10, M-15, M-25, M-40, and M-60. The M-7 is a 2 inch meter often used for diesel loading at 150 to 400 L/min. The M-15 fits 3 inch lines up to 1000 L/min. The M-40 handles 4 inch bunker lines from 800 to 3500 L/min depending on viscosity and line pressure. These flow ranges are approximate. Always check the meter curve with actual product viscosity, because capacity drops as viscosity rises.

Installation Requirements and Common Mistakes

Install the meter after a strainer. A 100 mesh basket strainer works for most refined products. Install an air eliminator upstream. Air bubbles count as volume in a rotary vane meter. If you skip the air eliminator, you will record phantom volume. Back pressure valves help when the line discharges to an atmospheric tank. Keep enough back pressure to prevent vaporization, especially for gasoline and LPG. A back pressure of 1.5 to 2 bar works in many truck loading racks.

We have seen installations in West Africa where a missing air eliminator caused a 2 percent error on a diesel export line. The meter was accurate. The system was not. Because a stuck air pocket creates a false volume count.

Digital Output and Companion Instruments from Silver Instruments

A rotary vane meter often needs companion devices. Silver Instruments supplies pressure transmitters, PT100 temperature sensors, paperless recorders, and flow computers. The pressure transmitter sends 4-20 mA HART signals to the control room. The PT100 compensates volume to standard conditions. A paperless recorder logs total flow, temperature, and pressure for audits. We can also supply oval gear flow meters as a lower cost alternative for clean diesel lines.

Last year a customer in Vietnam asked us for a backup meter for a diesel bunkering line. The line ran at 2500 L/min with a viscosity of 4 cP at 30 degrees Celsius. We supplied a 4 inch meter and a 12 channel recorder to log flow, pressure, and temperature. The system has been in service for 14 months.

When to Select an LC Rotary Vane Meter

Select this meter type when you need batching accuracy on truck loading, railcar loading, or ship bunkering. It works well for custody transfer if local regulations accept positive displacement meters. It is not the best choice for dirty products without fine filtration. Solids can jam the vanes.

Send us your product type, flow range in L/min or m3/h, pipe size in DN, operating pressure in bar, and ope