The new constant power technology thermal mass flow meters from Fluid Components International (FCI) are designed to assist engineers with gas flow metering at remote oil/gas production sites having unreliable power supply. Oil and gas production field engineers are required to monitor and report on emitted (flared) gases at these remote sites to meet local and global environmental compliance requirements.
FCI’s constant power technology meters require very low power compared to the alternative constant deltaT (variable power) technology, making them ideal for use with a solar panel.
A recent application used a solar power-able FCI Model ST75V flow meter with built-in Vortab flow conditioner to provide direct mass flow measurement of the waste gas being burned at the site. A result of the separation of hydrocarbon fluids at the well head, the waste gas was unsuitable for commercial use and was being sent to a tank with a flare unit to be burned off as necessary. Comprising of a mixed combination of flammable gases including methane, ethane, propane, isobutene, butane, isopentane, pentane and hexane as well as trace amounts of nitrogen and carbon dioxide, this waste gas also contained moisture. The gas line from the tank to the flare was a small 1-inch diameter pipe and had a very limited straight-run.
FCI’s flow meter with its no-moving parts thermal dispersion mass flow sensing element was found suitable for the application. The FCI Model ST75V flow meter with built-in Vortab flow conditioner provides direct mass flow measurement of the gas at this site without the additional equipment required by other flow measurement technologies.
Key features and benefits of FCI Model ST75V flow meter include a non-clogging sensor design operating over a wide flow range with low-flow sensitivity; integral Vortab flow conditioner providing a fully developed flow profile in just seven total pipe diameters; compatibility with solar power systems that provide 24Vdc power without any special modifications; rugged NEMA 4X/IP67 rated enclosure ideal for dirty oil and gas production field installations; inline-style flow body providing accuracy to ±1% of reading with flow ranges from 0.04 to 560 SCFM (0.07 to 950 NCMH), depending on pipe size, and repeatability of ±0.5 percent of reading; and suitability for line sizes from 0.25 to 2 inches (6 to 51 mm) in diameter.
The ST75V flow meter’s flow element is constructed with a 316L stainless steel body and Hastelloy C-22 thermowell sensors to resist corrosion. The instrument is approved for use in hazardous/explosive oil/gas production environments and carries global approvals that include: FM/CSA, Class 1, Div 1, Groups B, C, D; Class 1, Div II, Groups A-D, ATEX/IECEx Zone 1, II 2 G Ex d IIC T6 …T3, II 2 D Ex tD A21 IP67 T90°C…T300°C.