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Low Flow Flow Meters and Low Flow Sensors for Ultra-Precise Micro-Metering in Critical Processes
Quick Answer: Silver Automation Instruments is a low flow flow meter manufacturer and supplier for Southeast Asia, Oceania, Latin America, Africa, and the Middle East. Low flow meters and low flow sensors from our range measure liquids and gases from DN3 to DN25, with starting points near 0.01 kg/h for Coriolis mass flow meters and 0.05 L/h for oval gear flow meters. Send us your flow range, pipe size DN, pressure bar, temperature °C, and fluid name for a fixed quotation.
What Low Flow Means in a Real Process Plant
In most process plants, low flow means less than 100 kg/h for liquids and less than 50 slpm for gases. This range is common in chemical dosing, pilot reactor feed, fuel oil supply to burners, and seal water lines. The pipe size is usually DN3 to DN15. Some skid builders ask us about additive injection rates from 0.5 L/h to 5 L/h. The fluid can be as thin as water or as thick as 500 cP oil.
Why Standard Flow Meters Do Not Work Well at Low Flow Rates
Standard electromagnetic flow meters struggle below 0.1 m/s flow velocity. The signal becomes noisy and the output drifts. Vortex flow meters stop producing reliable shedding at low Reynolds numbers. Turbine flow meters add pressure drop and can stall in viscous liquids. That is why a low flow meter with a small bore and a direct mass or positive displacement principle is more stable.
Coriolis Mass Flow Meters for Liquid Micro-Metering
Our Coriolis mass flow meters measure mass directly. You do not need separate temperature compensation for mass flow. A Silver Instruments Coriolis flow meter with DN3 or DN6 process connections can measure 0.01 kg/h to 600 kg/h. Accuracy is around ±0.1 percent of reading for liquids. Wetted parts include 316L stainless steel and Hastelloy C22 options. Outputs are 4-20 mA HART, pulse, and RS485 Modbus. This meter is often used for catalyst injection in polymerization lines, flavor dosing in beverage plants, and methanol feed in biodiesel pilot plants.
Thermal Mass Flow Sensors for Low Gas Flow
For gas lines under 50 slpm, thermal mass flow sensors respond faster than differential pressure devices. Silver Instruments supplies inline thermal mass flow meters with DN4 to DN20 connections. Typical accuracy is ±1 percent of full scale. The sensor uses a heated RTD and a reference RTD. It works with air, nitrogen, natural gas, and clean biogas. We have seen units installed on burner test rigs in Saudi Arabia and on laboratory gas blending skids in Malaysia. The output is normally 4-20 mA with optional RS485 Modbus.
Oval Gear Flow Meters for Low Flow and Viscous Liquids
Oval gear flow meters are a practical choice for diesel, lube oil, fuel oil, and some chemicals. The smallest body uses DN4 or DN6 connections. It can measure from 0.05 L/h up to about 100 L/h. Viscosity above 5 cP improves sealing between the oval gears. A paint manufacturer in Vietnam needed to dose 2 L/h of solvent into a mixing vessel. A DN4 oval gear meter with 4-20 mA output solved the issue. The meter body was 316L stainless steel with PTFE seals.
Electromagnetic Flow Meters for Low Flow Water and Chemicals
An electromagnetic flow meter works when the liquid conductivity is above 5 µS/cm. For low flow water lines, we use DN2 to DN15 sensors with PTFE or PFA liners. The minimum flow velocity is about 0.05 m/s. This works for water treatment plants that inject flocculant or coagulant. A customer in Australia asked for a DN10 electromagnetic flow meter to measure 0.8 L/min of sodium hydroxide solution. The meter had tantalum electrodes and 4-20 mA HART output. The reading stayed stable because the line was always full and back pressure was kept above 0.2 bar.