Choosing the right primary device can be a challenging decision in the design of a hydrocarbon liquid measurement station. There are many factors to consider, including fluid phase, composition, viscosity, flow rate, pressure, temperature, flow profile, measurement objectives, and budget. While there are many primary devices from which to choose, a turbine meter can cost-effectively provide reliable measurement results when appropriately deployed.
In simplest terms, a turbine meter relies on rotating blades to produce a pulse output which is proportional to the flow. As the fluid flow increases, the spin rate of the turbine also increases, with a standard pulse output for each rotation. Among the benefits of turbine meters for hydrocarbon liquid measurement are the following:
- Turbine meters are capable of accurately measuring a wide range of hydrocarbon liquids;
- Both heavy and light liquid streams can be precisely measured with varying blade and rotor designs;
- The turndown ratio (i.e., the maximum to minimum flow rate ratio) is typically 10:1 with turbine meters; therefore, this device is often the preferred choice for measurement applications where flow rates are expected to routinely vary;
- Turbine meters can achieve 0.25% linearity across normal turndown ratios; and
- The repeatability of turbine meters allows for consistent proving runs which satisfy industry standards (e.g., API MPMS Chapter 4 "Proving Systems").
Based on turbine meters’ reliability, repeatability, and affordability, they are often selected for liquid measurement custody-transfer applications and are well-suited for variable flow rates. Whenever considering turbine meters as the primary element for your hydrocarbon liquid application, be sure to consult with your measurement experts, whether in-house or third party.
"We all make choices, but in the end our choices make us."
~ Ken Levine, American game developer