Optimising Hydraulic Performance: Precision Flow Measurement Challenges

Titan Enterprises shares practical insights to help engineers and operators address the challenges of precision flow metering, ensuring accurate measurements and safe process operations.

The complexity of hydraulic flow measurement

At first glance, metering liquids under pressure may appear straightforward – install a flowmeter, connect an instrument, control the measurement with software, wire in a valve and pump, then switch on the system. However, real-world applications reveal many complexities that must be managed to achieve precise and repeatable results.

Today’s process and fluid handling systems demand highly accurate flow measurement. Even small inconsistencies in system design can cause errors, wasted product or process disruption.

In hydraulic systems, flowmeters are essential to maintaining performance and integrity. They are used in hydraulic test rigs, calibration, pump output confirmation and flow control valve adjustment. Because hydraulic systems rely on precise fluid movement to transmit power, any deviation from the required flow rate can result in performance issues, accelerated wear or system failure.

For example, temperature changes across the day can alter fluid viscosity and volumetric flow rates, affecting accuracy. Effective system design should therefore minimise as many variables as possible within cost constraints. With this foundation, flowmeters, pumps and valves can then be selected to compensate for any variations.

The role of flowmeters in hydraulic systems

Flowmeters measure the rate or volume of fluid passing through a system and can provide anything from simple mechanical displays to full data logging. Real-time monitoring allows operators to track system health, detect leaks or blockages and optimise performance.

Accurate flow measurement also ensures consistent pressure and delivers the correct volume of fluid to actuators and other components – vital for achieving the required mechanical output.

Hydraulic fluids are usually viscous oils, petroleum or synthetic-based, chosen for stability at operating temperatures and lubricating properties. Water-based liquids (HFA, HFB), water glycol fluids (HFC) and increasingly biodegradable hydraulic fluids are also widely used.

Critical considerations for hydraulic fluid systems

1. System repeatability:
   Hydraulic stability is crucial. Air pockets can create dynamic flow situations and volumetric errors. A hydraulically locked system eliminates variability and improves repeatability.
2. Stable process conditions:
   Changes in pressure, temperature or flow rate can push flowmeters outside calibration zones, reducing accuracy. Maintaining stable conditions is key.
3. Managing pulsating flow:
   Pump type selection helps avoid pulsation, which can disrupt flow rates. Pressure regulators and dampers ensure a smoother, constant flow.
4. Flowmeter placement:
   Installing the flowmeter just before the dispense valve minimises fluid inertia and enhances accuracy.
5. Viscosity impact:
   Fluid viscosity directly affects accuracy. Turbine meters lose performance with high viscosity, whereas positive displacement meters improve accuracy and range.
6. Valve selection and calibration:
   Shut-off valve choice impacts delivery accuracy. Fast-acting solenoids suit small pipelines, while larger systems benefit from multi-stage shut-off or “automatic overrun compensation” programming.
7. Optimising electronic flowmeters:
   High-performance meters, such as Titan’s ultrasonic Atrato® flowmeter, can predict stop signals in advance to ensure consistent results at high speeds.

Enhancing process efficiency

Hydraulic systems, particularly in aerospace, are now operating at higher pressures to reduce component size, improve efficiency, cut reservoir requirements and reduce system weight. As pressures increase, the choice of flowmeter becomes more critical. Devices must provide accurate measurement while also withstanding pressures beyond maximum operating levels, with safety factors built in for long-term reliability.

By considering these factors during design and commissioning, and selecting the right flow measurement technology, engineers can avoid common pitfalls and achieve precision and consistency in hydraulic flow systems.

Titan Enterprises supplies flowmeters for hydraulic systems rated from 10 to 950 bar, with bespoke and OEM options available.

For more information on advanced flow measurement solutions and OEM applications, visit www.flowmeters.co.uk or email sales@flowmeters.co.uk