option

Flow meters for chemical injection devices

November 17, 2025
admin

Flow meters for chemical injection devices

 

JN30FXLH0000
10504
E.FLOW 1 EPDM PVC 10 BAR DN 15-100 10500

Chemical injection systems are indispensable in the oil and gas industry, petrochemicals, refineries, power generation, pharmaceuticals, and many other sectors. Their function is to    precisely  and continuously inject        various chemicals   into process lines. Flow meters play a crucial role in these systems,     as     even the slightest errors in the injection rate can have the following consequences    :

  • Interruption of the process

  • Prices for chemicals are rising.

  • Device corrosion

  • Decrease in plant efficiency

  • This leads to security problems.

Yes.

In this article, we will provide a comprehensive analysis     of the definition, types, operating principles, selection criteria, problems, applications, standards, and important role of flow meters in chemical injection systems  .

What is a flow meter? What function does it have in a chemical dosing system?

A flow meter is a device that     measures the volume or mass flow of injected chemicals  and transmits the information to the control system or operator.

In chemical injection devices, the flow meter fulfills the following functions:

✔Precise injection speed measurement

✔Displays the actual delivery rate of the dosing pump.

✔Avoidance of under- or overdosing

✔If the pipe is blocked, an acoustic signal will sound.

✔Collection of operational information for quality control.

✔Assistance with packaging calibration

Without flow meters, dosing systems are virtually uncontrollable and rely solely on the operator’s judgment, which can seriously impair chemical processes.

Why is a flow meter needed in a chemical dosing device?

  1. Chemicals are expensive.
    Many of them, such as amines, methanol, preservatives, antifouling agents, and disinfectants, are also costly. Accurate measurement prevents waste.

  2. The industry standard (API 675) requires controlled water injection.
    In the oil and gas industry, the control of water injection is subject to strict regulations.

  3. An overdose can be dangerous;
    for example, an overdose of corrosion-resistant materials can lead to the formation of a sticky layer on the device.

  4. An insufficient water supply can damage equipment.
    For example, an inadequate amount of water in the limescale protection system of a cooling tower can lead to blockages and consequently to the shutdown of the system.

  5. Without flow meters, direct monitoring is impossible.
    Without flow meter data, intelligent systems and programmable logic controllers (PLCs) cannot perform precise control.

Types of flow meters used in chemical injection equipment

Depending on the chemical type, viscosity, corrosion resistance, flow rate and pressure, there are many types of flow meters suitable for injection devices.

In the next step, we will introduce you to the best flow meters for tank calibration.

1. Magnetic flux meter

Suitable for conductive liquids (high conductivity).

Advantages:

  • No moving parts

  • extremely high precision

  • Possesses excellent corrosion resistance.

  • Low voltage drop

Border:

  • Only applies to conductive materials.

  • Suitable for water, sparkling water, acidic water, lemon water, etc.

2. Coriolis mass flow meter

The world’s most precise flow meter.

Advantages:

Areas of application:

  • Protection against industrial corrosion

  • viscous materials

  • Wash

Border:

  • The price is very high.

3. Ultrasonic flow meter

This is a good option for small and medium-sized transport companies.

Advantages:

  • Avoid contact with liquids (additives).

  • Suitable for aggressive liquids

  • Easy installation

  • Low maintenance costs

Key features:

The single-image version is suitable for clean liquids, while the Doppler version is suitable for liquids containing solid particles.

4. Rotary flow meter

The low-injection-flow packaging model is traditional, but widely used.

Advantages:

  • Low price

  • Easy installation

  • Live broadcast from Dubai

Border:

  • Average accuracy

  • Suitable for small pipes with low flow rates.

5. Turbine flow meter

Suitable for low viscosity liquids.

Advantages:

  • High precision

  • Reasonable price

Border:

  • It contains moving parts and requires regular maintenance.

  • Sensitive to suspended particles

6. Displacement flow meter

Suitable for materials with low flowability and high viscosity.

Advantages:

  • High precision

  • Suitable for oils, adhesives and polymers.

Border:

  • Sensitive to solid particles

  • Regular maintenance is required.

Which flow meter is best suited for chemical injection systems?

The choice depends on the type of liquid:

Material type The best flow meter
Corrosive substances (H₂SO₄, NaOH, HCl) magnetic or ultrasound
Corrosion-resistant materials Coriolis
Non-conductive materials Coriolis
viscous liquid PD or Coriolis
Water and thinner Rotary flow meter or magnetometer
Liquids containing molecules Doppler ultrasound

The role of flow meters in the automated control of injection components

Flow meters typically send     4- to 20-mA pulses or     Modbus signals to a control panel or programmable logic controller (PLC). The control system uses this data for the following purposes:

  • Pump dosing speed control

  • Stop the injection as soon as the flow rate reaches zero.

  • Adjust the flow rate to the process requirements.

  • Records of injections are kept

  • Send an alarm to the control room

Therefore, flow meters are     an important component of intelligent chemical dosing devices.

Recommendations for selecting suitable flow meters for chemical dosing devices

To make the right decision, you should consider the following points:

1.     Types of materials and their chemical properties

  • corrosion

  • electrical conductivity

  • Joe

  • Presence of suspended particles

2.     Injection flow rate

The flow rate of the injection device is typically     1 to 2000 liters per hour     .

3.     Pressure in the line

Some flow meters have pressure limiters.

4.     Connection type of the flow meter

  • lip

  • thread

  • Tongs

5.     Accuracy is required.

Depending on the sensitivity of the process:

  • Cleanroom: Medium accuracy

  • Oil and gas: High accuracy

  • Pharmaceutical industry: extremely high precision

6.     Output signal type

It plays an important role in achieving automatic control.

Problems with the use of flow meters in chemical injection devices

1. Blocked pipes

It is particularly suitable for lime water, descaling agents and materials containing solid particles.

Solution:
Use ultrasound waves or Coriolis force with a linear smoothing method.

2. Errors in measuring viscous liquids

Some flow meters are not accurate enough.

Solution:
Apply the PD or Coriolis effect

3. Corrosion of metal flow meters

Acidic substances can be harmful to the body.

Solution:
Flow meters made of PVDF, PTFE or Hastelloy-C materials.

4. Air bubbles are present.

This phenomenon frequently occurs in injection tubes and can lead to measurement errors.

Solution: Use a well-designed  exhaust valve  and  a fuel injection manifold .

Important criteria for flow meters used in chemical injection

  • API 675   (for pumps and    flow rate     )

  • API 14C     (Safety of platform injection systems)

  • IEC 60529     (standard for the protection of intellectual property)

  • ATEX / EX (suitable for use   in potentially explosive     atmospheres)

  • NACE MR0175     (Corrosion protection in the oil and gas industry)

  • ISO 4064 / OIML R49      – For precision flow meters

Application of flow meters in injection systems

  1. Introducing corrosion inhibitors into oil and gas pipelines

  2. Injecting    an anti-limescale agent   into a cooling tower

  3. Chlorine or hypochlorite is injected into wastewater treatment plants.

  4. Injection of defoamer in industrial plants

  5. To adjust the pH, add acid or sodium bicarbonate.

  6. Methanol or ethylene glycol was introduced into the gas pipe.

  7. Amine injection into a gas desulfurization plant

Advantages of using flow meters in chemical injection systems

  • The injection speed is controlled with extreme precision.

  • Reduce your use of chemicals

  • Prevention of corrosion or deposit formation on systems

  • Online and automated monitoring is possible.

  • Extending the service life of dosing pumps

  • Data logging operation

  • Reduction of the human factor

  • Can be used under high-pressure and high-temperature conditions.

In conclusion

Flow meters are     critical components of chemical dosing systems and play a key role in     accuracy, safety, stability, and controllability    . Selecting the right flow meter depends on the following factors:

The situation will be different.

  In general, the highest efficiency and lowest errors in chemical injection devices are achieved by using     Coriolis flow meters, magnetic flow meters, or ultrasonic flow meters.