When choosing and installing a flowmeter you should pay attention to the specification, read the specification and you’ve guessed it – read it again! Get this wrong and you are likely not going to achieve a trouble-free installation, and even risk damaging the flow meter beyond repair.
After careful consideration of flow meter application parameters including flow, pressure, fluid type and properties plus required function, you should look at the proposed installation location for your flowmeter and take note of its full operational envelope.
Prior to even specifying a flowmeter we recommend that you read the manufacturer’s instructions of the product you are considering as this may change your choice if certain requirements you have cannot be accommodated. Often you will have to make a compromise as illustrated with these real-world challenges experienced by Titan customers.
Case study 1:
Due to its low cost our customer first considered using a turbine flowmeter for their target application as it could make the required measurements easily. Unfortunately the installation environment for this application was very convoluted as no straight lengths of upstream and downstream pipework were possible which would result in unreliable readings using a turbine flowmeter. As a consequence, choosing a positive displacement meter, such as Titan’s oval gear meters, would be a far better option. While the initial outlay might be higher for the oval gear meter, the longer term installed cost and performance advantages justified this initial extra expenditure.
Case study 2:
Another customer needed to meter the flow of a liquid up to 60°C in a location next to a furnace with radiant temperatures well above the operating specification envelope of many flow meters. With one installation we had repeated turbine flowmeter failures even though the application was well within the flowmeter’s operating limits. It transpired that the customer had put the flowmeter at the end of a very long pipe run which drained down completely every night. On start-up the fluid pushed a vast quantity of air at high speed in front of it. This spun the turbine to excessive speeds which was then met with a slug of fluid which rotated the impellor at a much lower RPM. An overspeed is bad news but when followed by a rapid deceleration it is even worse. Titan solved the problem by installing a simple non-return valve that prevented the system from draining down and made the use of the turbine flowmeter reliable and perform at its optimum.
Finding the ideal flowmeter for your application can be complicated and there are several options for any given low flow rate. The final choice is likely to be a compromise between performance, price and operating parameters.