1. Specify flow meter: flow rate:

In some cases, the user does not know what the flow rate is in the traffic pipeline."That's why we measure it." Plant construction is often such that for mechanical reasons the pipes used are much larger than just the size required to carry the flow.Then we have to start looking at the dynamics and pipeline considerations behind the flow.Often, users ignore/forget that their processes are significantly pulsated, and peak flows can be forty percent higher or even twice as high on average.

2. Specify flow meter: temperature:

Some users do not read the maximum operating temperature specifications of their meters and assume that all flow meters operate at 150°C.When the instrument fails, the product fails!Similar to how cell phone manufacturers put water mark markers in cell phones, we now include irreversible high temperature markers in the instruments to record whether the maximum operating temperature is exceeded for any length of time.

3. Specify flow meter: viscosity:

Many users are unaware that many flow meters are viscosity sensitive and will significantly change their calibration as fluid properties change.These Reynolds number sensitive devices are typically only linear in the "turbulent" flow range, and their performance degrades as the fluid flow becomes more "smooth."For example, using a 40cSt lubricant will immediately calibrate the turbine flow meter 1cst from the rated flow meter, exiting the turbulent flow region and entering the nonlinear laminar flow region.Changes in temperature will change the viscosity and calibration factor.Many flow meter types rely on higher Reynolds numbers for their linear performance including Vortex shedding, pelton wheels, variable area and most differential pressure devices.Other techniques such as positive displacement,

4. Specify flow meter: output type:

"Does the flow meter interface with my instrument?" We don't know, what are the input requirements for the instrument?Logic levels, NPN or PNP pulses, analog current or voltage or a higher level language?Please check this requirement before specifying a meter!

5. Specify flow meter: pipe connection:

The piping connections you choose should be dictated by your process flow rates.A flow meter operating at 100ml per minute is unlikely to have 1" NPT pipe threads.Typically, small flow meters will have small pipe connections.Specifying the correct thread of the flange details is essential, don't just specify the size of the thread.

6. Specify flow meter: pressure drop:

This is a very important consideration.Is the available pressure head sufficient to operate the flow meter you choose, and is there still enough available for future processes?This is often overlooked, resulting in delays in commissioning as alternative products or more suction capacity are required.

7. Specify flow meter: pulsating flow:

As already mentioned, pulsating flow can cause problems for most flow meter types There is no doubt that positive displacement devices are most immune to the honorable intolerance shared by all other flow meter types.It is always best practice to eliminate pulsations with dampers and pressure regulators.It can be a simple air bag and a length of flexible tubing or a commercial air bag damper with appropriate gas inflation and a high-quality pressure regulator.Both methods will reduce pulsation, but only within a limited set of operating parameters.Change the pump's stroke, frequency or flow and the damper's efficiency will decrease.

8. Specify flow meter: environment:

Is your flow meter outside the Alaskan winter or affected by the Saharan summer?Is it in a hazardous area on an offshore oil rig?We have had users forget to mention all of the above.Environmental specifications are particularly important in hazardous areas where flow meters require appropriate instrumentation and detectors.

9. Specify flow meter: power requirements:

All flow meter manufacturers try to immunize their products from bad power supplies.Most experienced users will specify a good quality power supply for the sensors around their factory.Then someone will add solenoid valves, DC motors, and other noisy appliances and wonder why they are having problems with their flow meter electronics.If you have an analog output you will need a suitable voltage supply, it won't work at 9V.

10. Specify flow meter: installation constraints:

"I didn't realize I needed to use straight pipe before and after the flow meter!" Check your flow meter installation instructions as well as the meter specifications before specifying.If your operating space is tight, consider a positive displacement gauge, which will be largely insulated from surrounding pipes.Do you need a filter?It is good practice to install a filter near the flow meter, but few users rely on other parts of the system.Will your fittings affect the flow curve on your flow meter?