The Positive Displacement (PD) flow meter is ideal for handling very low flows. It has minimal slippage, so it accurately records very low flows. Flowquip offers the MG and Tri-Gear PD flow meter series, which operate as low as 0.5 liters per hour with accuracies better than 1% of reading. Moreover, these low flow meters are available in anodized aluminum and stainless steel, providing a cost-effective solution for accurate low flow measurement.
For more demanding applications involving very low flows, Flowquip offers flow meters from the VAF range of PD flow meters. Specifically, the VAF Milliflow M31 piston flow meter and the J3010 Vane Meter are ideal solutions. They are made of stainless steel and come with standard VAF options, including a non-reset mechanical totalizer and single/dual NAMUR ATEX Pulse Transmitters. Furthermore, the M31 has a standard flow range of 1 to 20 liters per hour, but for higher viscosity products, the minimum flow can be greatly reduced. Additionally, the J3010 version can operate between 4 and 250 liters per hour.
Variable Area Flowmeters: A simple ‘float in a tube’. Probably the least expensive and least accurate of all low flow flowmeters but eminently suitable where a visual indication of flow is all that is required. Care must be taken with regard to not exceeding working pressure and temperature limits … particularly in the case of plastic tube units. V/A flowmeters are available for flows as low as 1 cc/min and can be fitted with an integral needle valve for flow regulation. It is critical to know the precise working pressure when placing an order so the low flow flow meter can be scaled correctly as changes in working pressure effect air density and cause measuring errors.
Calorimetric Flow meters (or Thermal Mass Flow Meters): are available from ¼” bore fitted into a stainless steel measuring section (spool piece) with threaded process connections handling flows as low as 0.05 SCMH . The flow sensor is calibrated whilst installed in the measuring section to ensure optimum accuracy and performance. An integral display shows flow rate and total in various volumetric or mass engineering units and also provides a scaled pulse and 4-20mA outputs. This low flow flowmeter provides a very wide operating flow range with a measuring error of 1.5 to 2%. The calorimetric flowmeter offers excellent accuracy and reliability at a very affordable price and on a short lead time too. ATEX Approved versions are available for Hazardous Area installations.
Coriolis Flow meters: probably the most expensive but the most accurate measuring solution. As density and viscosity of all liquids and gases are affected by changes in temperature and pressure the Coriolis flow meter is a good choice when it comes to flow measurement. A true and accurate mass or volume reading is provided regardless changes in the characteristics of the flowing medium. This type of low flow flowmeter offers no obstruction to flow although the shape of the measuring tubes may create a small pressure loss. Straight tube Coriolis flowmeters can be employed where pressure drop is an issue. Measuring accuracies of better than 0.5% of reading can be obtained over a wide operating flow range. ATEX Approved versions are available for Hazardous Area installations.
For more information on Flowquip's range of flow meters, call us on 01422 829920 or email [email protected]
