Liquid Mass Flow Switches
Description
Liquid mass flow switches are devices designed to measure the flow or quantity of a moving liquid in terms of mass per unit time, such as pounds per minute. These devices can either be sensors with electrical output or stand-alone instruments equipped with local displays and controls. They are essential for accurately quantifying the mass flow rate of liquids in various industrial processes.
Working Principle
Liquid mass flow switches operate based on several measurement technologies, including inferential flow measurement, positive displacement, velocity meters, and true mass flow meters. Inferential measurement involves indirectly measuring flow by directly measuring another value and inferring the flow based on established relationships. Differential pressure is commonly used as an inferred measurement of a liquid's flow rate. Positive displacement meters directly measure liquid flows by dividing the fluid into specific increments and moving it along, often used for high viscosity fluids. Velocity meters operate linearly with respect to volume flow rate, offering greater range ability. True mass flow meters, such as thermal meters or Coriolis meters, measure the mass rate of flow directly. These technologies provide critical data for process control and optimization.
Applications
Liquid mass flow switches are widely used in various industrial applications. In refinery water applications, they are employed for pump protection and valve leak detection. Thermal flow switches, in particular, are favored in these settings due to their reliability and lack of moving parts, which contribute to a mean time between failure (MTBF) rating of 190 years. They are also used in cooling towers to protect against fluid delivery pump failures by detecting low flow conditions and triggering alarms to prevent system damage.
Limitations
One limitation of liquid mass flow switches is their sensitivity to the type of media they are exposed to. For example, mechanical flow switches like paddle switches can be effective but are prone to wear and corrosion damage. Ultrasonic flow switches, while easy to install and free of moving parts, may experience reduced accuracy at low flow rates and can be affected by pitting or fouling of the pipe.
Considerations
When selecting a liquid mass flow switch, several factors should be considered, including initial costs, operating expenses, durability, accuracy, and maintenance costs. Thermal flow switches, for instance, offer exceptional reliability and low maintenance due to their lack of moving parts. However, the specific requirements of the application, such as the accuracy and repeatability needed, the plant and process environment, and the installation and maintenance conditions, should guide the choice of flow switch technology.
from ABB Measurement & Analytics
With no up or downstream piping requirements the compact flowmeters can be installed in the tightest spaces, enabling applications not possible before. The FCH100 series delivers: EHEDG, hygienic certification. Superior accuracy and speed for filling applications. Full parameter access with up to... [See More]
- Process Media Type: Liquid; Gas
- Pipe Diameter: 0.25 to 4.00
- Meter Technology: Coriolis
- Mounting: In-line
from Fluid Components Intl. (FCI)
The FLT93C insertion and inline type FlexSwitches for sanitary flow, level and temperature monitoring represents the first true technological breakthrough in thermal technology in over a decade. This product is specifically designed for sanitary 3A process applications. FCI is the only thermal... [See More]
- Process Media Type: Liquid; Gas
- Mounting: Insertion
- Meter Technology: Thermal
- End Fittings: In-line Flanged
from ABB Measurement & Analytics
HygienicMaster FEH610 is ideally suited for hygienic standard applications featuring all functions required - no more and no less. The perfect device for everyday applications. Simple and economical. Field-proven powerful and flexible transmitter technology. – ABB common HMI concept. –... [See More]
- Process Media Type: Liquid
- Mounting: In-line
- Pipe Diameter: 0.04 to 4.00
- End Fittings: In-line Clamp (optional feature); In-line Flanged (optional feature); Socket Weld / Union (optional feature); In-line Threaded (optional feature)
from Fluid Components Intl. (FCI)
The FLT93L inline type FlexSwitch for flow and temperature monitoring represents the first true technological breakthrough in thermal technology in over a decade. FCI is the only thermal manufacturer providing temperature compensation to ensure set point accuracy for process temperatures that vary... [See More]
- Process Media Type: Liquid; Gas
- Pipe Diameter: 0.75 to 1.00
- Meter Technology: Thermal
- Mounting: In-line
from ABB Measurement & Analytics
HygienicMaster FEH630 – The first choice for all hygienic applications. Advanced features and functionality that enable you to operate more efficiently, reduce costs and increase profitably. Real-time diagnostic keep your process up and running. – Detecting critical process conditions at... [See More]
- Process Media Type: Liquid
- Mounting: In-line
- Pipe Diameter: 0.04 to 4.00
- End Fittings: In-line Flanged; In-line Threaded
from Fluid Components Intl. (FCI)
The FLT93B BASIC insertion type FlexSwitch for flow and temperature monitoring represents the first true technological breakthrough in thermal technology in over a decade. FCI is the only thermal manufacturer providing temperature compensation to ensure set point accuracy for process temperatures... [See More]
- Process Media Type: Liquid; Gas
- Pipe Diameter: 0.75
- Meter Technology: Thermal
- Mounting: Insertion
from Litre Meter Limited
With some of the finest coriolis engineering minds in the industry,. TRICOR Coriolis Technology is taking steps beyond the norm. to bring you a state-of-the-art line of Coriolis flow instruments. [See More]
- Process Media Type: Liquid
- Mounting: In-line
- Meter Technology: Coriolis
- End Fittings: In-line Flanged (optional feature); In-line Threaded
from Sierra Instruments, Inc.
Overview. The InnovaSwitch insertion-type level switch is a high-performance, industrial-grade liquid level indicator for tanks and process vessels. This product switches on level changes as small as 0.03 inch (0.8 mm) on dry-to-wet and wet-to-dry occurrences in a tank or vessel. The instrument was... [See More]
- Process Media Type: Liquid; Gas
- Mounting: Insertion
- Meter Technology: Thermal
- End Fittings: In-line Threaded
from Bionetics
Rheotherm flow sensing probes for duct gases are easy to install and provide long-term service with little or no maintenance. The output can be in mass, standard volume or velocity units. Options for hazardous locations (intrinsically safe/explosion-proof) are available. [See More]
- Process Media Type: Liquid; Gas
- Pipe Diameter: 1.00 to ?
- Meter Technology: Thermal
- Mounting: Insertion