Titan Enterprises shares key insights to help engineers and operators navigate challenges of precision flow metering to ensure accurate measurements and safe process operations.
Metering liquids under pressure may seem straightforward at first glance – install a flowmeter in the product line, connect it to an instrument, control the measurement with on-board software, wire in a valve and pump, and switch the flow system on. However, real-world applications reveal a host of complexities that must be addressed to achieve precise and repeatable results.
Today’s advanced process and fluid handling systems demand highly precise flow measurement, and even slight inconsistencies in system design can lead to inaccuracies, wasted product, or disrupted processes.
Where hydraulic systems are concerned, flowmeters play a critical role in maintaining the integrity and effectiveness of such systems used for instance, in hydraulic test rigs, calibration, confirmation of hydraulic pump outputs, plus setting and adjustment of flow control valves. Maintaining consistent process conditions, however, can be challenging. Hydraulic systems rely on the precise movement of fluid to transmit power, and any deviation from the required flow rate can lead to performance issues, excessive wear, or system failure. For instance, process conditions such as temperature fluctuations throughout the day can alter fluid viscosity and volumetric flow measurements, impacting flow measurement accuracy. Ideally hydraulic system designs should aim to minimise as many variables as possible within a reasonable cost. Once this foundation is established, equipment such as flow meters, pumps, and valves can be selected to effectively compensate for any parameter variations.
Flowmeters are designed to measure the rate and/or volume of fluid flowing through a hydraulic system via a variety of outputs, from a simple mechanical display to full data logging, providing real-time data on the rate of fluid movement. This enables operators to monitor system health, detect leaks or blockages, and optimise performance. Accurate flow measurement is also crucial for maintaining consistent pressure and ensuring that actuators and other components receive the correct volume of fluid, which is vital for achieving the desired mechanical output.
Hydraulic fluids are typically viscous oils, petroleum or synthetic-based, utilised for their stability at operating temperature and lubricating properties, although water-based liquids (HFA, HFB), Water Glycol Fluids (HFC) and increasingly Biodegradable Hydraulic Fluids are also used within hydraulic systems.
Critical Considerations for Hydraulic Fluid Systems
- System Repeatability:
Hydraulic stability is essential. Air pockets in the line can lead to dynamic flow situations, causing volumetric errors in delivery. Ensuring a hydraulically locked system eliminates such variability and enhances repeatability.
- Stable Process Conditions:
Changes in pressure, temperature, or flow rate can push flowmeters into unpredictable operational zones, affecting calibration and accuracy. Maintaining consistent conditions is vital for reliable performance.
- Pulsating Flow Management:
Selection of the pump type is important to avoid pulsating flow. Pulsation from certain pumps can disrupt flow rates, especially in aggressive chemical applications. Pressure regulators and pulsation dampers should be incorporated into flow systems to achieve a smooth and constant flow.
- Strategic Placement of Flowmeters:
Positioning the flowmeter just before the dispense valve minimises fluid inertia and improves measurement accuracy.
- Understanding the Impact of Viscosity on Flowmeter Accuracy:
Selection of any flow measurement device should always consider the fluid viscosity as turbine meters typically loose accuracy and performance as the fluid viscosity increases, whereas the performance, accuracy and range of positive displacement flowmeters increases with viscosity.
- Valve Selection and Calibration:
The type of shut-off valve used can impact delivery accuracy. Fast-acting solenoids are ideal for smaller pipelines, while larger setups benefit from solutions like multi-stage shut-off systems or “automatic overrun compensation” programming to fine-tune results.
- Optimising Electronic Flowmeters:
High-performance meters (such as Titan’s ultrasonic Atrato® flowmeter) can predict stop signals in advance, ensuring consistent delivery even at high speeds.
Enhancing Process Efficiency
Hydraulic systems, particularly in the aerospace industry, are operating at increasingly higher pressures to achieve several key benefits – namely, reductions in component size, improvements in overall system efficiency, smaller reservoir requirements, and decreased system weight and footprint. As operating pressures rise, the selection of an appropriate flowmeter becomes even more critical. These flowmeters must not only provide accurate measurements but also be capable of withstanding pressures beyond the system’s maximum operating levels, incorporating a suitable safety factor to ensure long-term reliability and safety.
By accounting for these factors during system design and commissioning and investing in the appropriate flow measurement technology that suits the application requirements, engineers can eliminate common pitfalls in liquid metering and ensure the liquid flow system performs with precision and consistency.
Titan Enterprises offer a range of flowmeters for hydraulic systems ranging from 10 to 950 bar, with bespoke flow variants and OEM versions also available. For further information on advanced flow measurement solutions and OEM applications, visit www.flowmeters.co.uk or email sales@flowmeters.co.uk.
