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Turbine Flow Sensors: Precision Pulse Frequency Output Modules for Fluid Fuel

Quick Answer: Turbine flow sensors with pulse frequency output are a practical choice for clean fuel fluids like diesel, jet fuel, and light oil. The output frequency is proportional to flow rate and works with PLC counters and batch controllers. For accurate fuel batching, specify fluid viscosity, flow range, pipe size in DN, and required signal type.

Silver Automation Instruments supplies turbine flow sensors for industrial fuel lines. A rotating rotor sits inside the flow path. Each blade passes a magnetic pickup. The pickup generates a pulse. Pulse frequency is linear with flow velocity. This signal connects easily to PLC high speed counters, batch controllers, and digital displays.

The standard output is a square wave pulse. Many models also offer a 4-20 mA HART output. But pulse output is the main reason turbine sensors work well for fuel dosing and totalization. A typical K-factor is 450 pulses per liter for a DN15 sensor. For a DN50 sensor it may be 75 pulses per liter. You calibrate the receiving device with this K-factor and get direct volume readings.

Where Pulse Frequency Output Works Best

Fuel loading terminals use turbine sensors on loading arms. A customer in Vietnam installed 12 units on diesel loading skids last year. They needed stable pulse output over 40 meters of cable to a control room. Shielded cable and a 24 V DC supply worked without signal loss. The flow range was 20 to 200 liters per minute per arm.

Marine fuel transfer is another common application. A ship service company in Singapore uses turbine sensors for MGO and MDO transfer. They measure fuel from 10 to 80 centipoise viscosity. The pulse output connects to a batch controller with temperature compensation. In practice, most technicians handle this after one commissioning visit.

In Africa and the Middle East, generator set manufacturers use compact turbine sensors on fuel return lines. Return flow is often smaller than supply flow. You subtract return pulses from supply pulses. The result is actual engine consumption. This method is common in mining camps and telecom towers.

Key Specifications for Fluid Fuel

Start with viscosity. Turbine flow sensors work well in clean liquids from 0.5 to 100 centipoise. Diesel and jet fuel sit in the low range. Heavy fuel oil above 100 centipoise can slow the rotor and hurt linearity. Use a positive displacement meter or a Coriolis mass flow meter for that fluid.

Temperature and pressure matter. Most standard turbine sensors handle -20 to 120 °C and up to 40 bar. A fuel line near a heat exchanger may exceed that. Specify a higher temperature bearing option if needed. For diesel, stainless steel 316 body and tungsten carbide bearings are a practical combination.

Flow range is another key point. A DN15 sensor may cover 0.6 to 6 liters per minute. A DN40 sensor may cover 10 to 200 liters per minute. Do not oversize the meter. Standard turndown is about 10:1. You can push it to 20:1 with clean fuel and low pulsation.

Output frequency range often falls between 10 and 1000 Hz. This range is compatible with most PLC high speed counters. A very high frequency may require a dedicated counter card. Check your PLC input spec before ordering. One OEM in Mexico ordered sensors with a K-factor that produced 2000 Hz at maximum flow. Their standard input module maxed out at 1000 Hz. We swapped the pick-up coil to reduce the pulse rate.

Installation and Calibration Tips

Install the sensor with straight pipe upstream and downstream. A typical rule is 10 pipe diameters upstream and 5 diameters downstream. Avoid elbows, partially open valves, or strainers too close to the sensor. Swirl affects rotor speed and pulse accuracy. But a straight run is cheaper and easier than a flow conditioner.

Always instal