New devices with low flow measurement capability are increasingly in demand by industrial and laboratory users as requirements for accurate low flow measurement devices proliferate.
The Hoffer MF Series has been developed to meet the need for a low flow measurement device for service on clean, low and moderate viscosity liquids, and for gas measurement applications.
The MF Series is a family of low flow rate measurement devices based on a pelton wheel like rotor. The measured fluid is directed tangentially thru a velocity nozzle against the pelton rotor causing it to rotate. The motion of the rotor is sensed by the pickup coil and converted to a pulsing output signal where the frequency is related to the flow rate, and the accumulated pulses are related to the total volume passing thru the flowmeter.
Materials Selection and Construction
Selection of the materials of construction is usually dictated by the requirements of performance, durability, media compatibility, availability, and cost considerations.
The materials of construction for the MF Series are intended to provide a standard flowmeter configuration which will suit the requirements of a broad base of industrial users. Our applications group can assist you in the selection of options that will provide the construction which offers the optimum combination of useful range, corrosion resistance and operating life for a particular application.
MF Series Turbine Flow Meters for Liquid
The liquid MF Series offers measurement capability from .007 to 3.5 GPM in twelve overlapping ranges for service on clean, low viscosity liquids.
Size selection may be accomplished by referring to Figure 4 after giving consideration to the service, construction, and the maximum allowable pressure drop. Fluid viscosity effects should be considered when the liquid’s temperature will be varying significantly in actual service.
Adequate back pressure on the flowmeter should also be maintained to avoid cavitation which may result in metering errors.
It should be observed that with the standard magnetic pickup, no preamplifier is required in many flow indicator applications and can transmit up to 200 feet. The Redi-pulse mag pickups are available and can transmit up to 5000 feet.
- 1/2” MS line size.
- Repeatable Flow Range is .007 to 3.5 GPM.
- Accuracy of +/-1% Linearity and +/-.25% Repeatability.
- Twelve overlapping size ranges.
- For clean, low viscosity liquids.
- Precision Low flow measurement of low viscosity, liquid applications within the process industries.
- Output Frequency Range: 50 to 1000 Hz (3333 Hz Maximum)
- Linearity: ±1.0% reading (over 10:1 range)
- Linear Range: 10:1 turndown with magnetic pickups and ball bearings
- Usable Flow Range: 25:1 with ball bearings
- Repeatability: ±0.1% typ. (±0.25% worst case)
- Reference conditions: 1 cstk. test fluid at 70° F
MF Series Turbine Flow Meters for Gas
MF Series meters may be used for gas flow measurement and come in 6 overlapping sizes detailed in Figure 7. Specific criteria must be met when using the MF Series on gas flow applications. Those criteria include constant gas pressure and constant gas temperature. There is no effective method for compensating the output of the MF Series due to changing pressure and temperature. Additionally, MF Series meters must be air or gas calibrated in order to produce accurate results. Consult the factory for specific sizing and calibration recommendations.
- 1/2” MS line size.
- Repeatable Flow Range is .005 to 1 ACFM.
- Accuracy of +/-2% Linearity and +/-.25% Repeatability.
- Six overlapping size ranges.
- Specific criteria must be met for gas flow applications. Consult the factory for specific sizing and calibration recommendations.
- Precision Low flow measurement of industrial gas applications within the process industries.
Reference : hofferflow.com