In-line Volumetric Gas Flow Switches
Last Updated: April 1, 2025
Description
In-line volumetric gas flow switches are devices designed to monitor and control the flow of gas through a pipeline. They are installed directly in the line of the gas flow and are used to detect the presence or absence of gas flow, ensuring that the system operates within the desired parameters.
Working Principle
In-line volumetric gas flow switches operate by sensing the flow of gas through a valve contained within the switch. When gas flows through the switch, it triggers a mechanism that sends a signal to a switching unit. This unit can then adjust the system by turning a pump or valve on or off to maintain the proper flow. These switches are useful because they help monitor flow characteristics such as volume, speed, and pressure, and can adjust for changes as they occur, ensuring system efficiency and safety .
Applications
In-line volumetric gas flow switches are commonly used in HVAC applications where they monitor air and steam flow to ensure optimal system performance. They are also employed in industrial settings for monitoring gas flow in pipelines, ensuring that processes operate smoothly and safely .
Advantages over other Volumetric Gas Flow Switches
In-line volumetric gas flow switches offer the advantage of being directly installed in the flow line, which can provide more accurate and immediate readings compared to non-invasive or insertion types. This direct installation can lead to quicker response times and more reliable monitoring of gas flow, which is crucial in applications where precise control is necessary .
Limitations
One limitation of in-line volumetric gas flow switches is that they can be affected by solid impurities in the gas, which may cause flow blockage at zero flow. Additionally, they may be sluggish in responding to quick changes in flow, especially at high differential pressures, which can pose a risk of overspeeding .
Considerations
When selecting in-line volumetric gas flow switches, several factors should be considered. Initial costs can vary depending on the complexity and specifications of the switch. Operating expenses may include energy consumption if the switch requires an external power supply. Durability is an important factor, as switches with moving parts may wear over time. Accuracy is crucial for maintaining system efficiency, and regular maintenance and replacement costs should be factored into the overall cost of ownership. It's also important to consider the compatibility of the switch with the specific gas type and operating conditions of the system .
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]
- Mounting: In-line
- Pipe Diameter: 0.75 to 1.00
- Meter Technology: Thermal
- End Fittings: In-line Flanged (optional feature); In-line Threaded
from Litre Meter Limited
RITTER bellows-type gas meters are applicable for measuring the volume of flowing inert and dry gases and are particularly effective at high gas flows. [See More]
- Mounting: In-line
- Process Media Type: Gas
- End Fittings: In-line Threaded
- Operating Pressure: 4.35
from Sitron
The CF12 series of thermal flow switches is designed to monitor flow status of liquids and gases and can also be used to detect level. A chain of 8 LED ’s gives the user a visual indication of the flow status of the switch. There are two red LEDs that indicate whether or not the unit has... [See More]
- Mounting: In-line
- End Fittings: In-line Threaded
- Pipe Diameter: 0.25 to 0.50
- Process Media Type: Liquid; Gas
from Bionetics
Rheotherm low gas flow meters provide an easy-to-use technology for measuring gas flow in small lines - typically 1" or smaller at flow rates from a few hundred SCFM down to 25 SCCM. (For flow measurement in larger pipes and ducts, click here). These meters give a repeatable reading in mass or... [See More]
- Mounting: In-line
- Pipe Diameter: 0.06 to 1.00
- Meter Technology: Thermal
- End Fittings: In-line Flanged (optional feature); In-line Threaded (optional feature); Tube End/Hose Nipple; Sanitary
from Malema Sensors
The M-100 Series is an extremely sensitive flow switch. It has been engineered to monitor vital sample flow parameters for instrumentation in process control and inert blanket gases. It is used as an auxiliary alarm monitor for flow meters and is ideally suited for applications when installed on a... [See More]
- Mounting: In-line
- Gas Volumetric Flow Rate: 0.0018 to 2.12
- Process Media Type: Liquid; Gas
from KOBOLD Instruments, Inc.
Product Features. Control of Very Small Liquid or Gas Flows. Wetted Parts - SS 1.4305, Borosilicate Glass, FKM. Proximity Switch or Reed Contact. Vertical Connection for In-Line Mounting. Flow switch types KSR and SVN operate on the same principle as a float-type flow indicator. Provided that the... [See More]
- Mounting: In-line
- Operating Pressure: 230
- Process Media Type: Liquid; Gas
- Media Temperature: 160
from Clark Solutions
Use the 7000/8000 series flow meters for measuring the flow rate of liquids, gases, compressed air and steam in closed pipes. We also make indicating flow switches and flow transmitters for process indication and control. Meters feature a large easy to read analog dial with 270 degree pointer... [See More]
- Mounting: In-line
- Pipe Diameter: 0.25 to 8.00
- Meter Technology: Orifice Plates
- End Fittings: In-line Threaded; Wafer
from Orange Research, Inc.
Fixed-Orifice Flowmeters. Our flowmeters are designed for those applications where a rotameter is not appropriate. Consider the inherent problems of rotameters--they are difficult to read, especially with dirty or opaque fluids, have low pressure ratings and allow vertical orientation only. Now... [See More]
- Mounting: In-line
- End Fittings: In-line Threaded
- Meter Technology: Fixed Orifice
- Process Media Type: Gas
from OMEGA Engineering, Inc.
This switch package offers a complete solution for flow or no-flow switching in pipes or ducting ranging up to 16". The compact relay controller provides reliable actuation of valves, pumps or blowers rated up to 1 /2 HP. Common applications include low flow pump or process protection. To complete... [See More]
- Mounting: In-line
- End Fittings: In-line Threaded
- Pipe Diameter: 0.75 to 12.00
- Process Media Type: Liquid; Gas
from Brooks Instrument
Features. Wide range of flow ratings. Operating temperature range 33 to 125 °F (1 °C to 52 °C). Pressure ratings up to 500 psig / 34 bar. Two accuracy levels to choose from: 2% or 1% Full Scale. Optional high and low-flow reed switch or inductive alarm, also for safe use in explosive... [See More]
- Mounting: In-line
- End Fittings: In-line Threaded
- Meter Technology: Rotameter; Variable Area
- Process Media Type: Liquid; Gas
from Malema Sensors
The M-100X Series is an extremely sensitive flow switch. This has been engineered to monitor vital sample flow parameters for instrumentation in process control and inert blanket gases. It is used as an auxiliary alarm monitor for flow meters and is ideally suited for applications when installed on... [See More]
- Mounting: In-line
- End Fittings: In-line Threaded
- Pipe Diameter: 0.12 to 0.25
- Process Media Type: Liquid; Gas
from Clark Solutions
The model DS15 flow meters work according to the proven variable area principle. The float is moved upward in a tapered tube by the flowing medium and its upper edge indicates the flow rate by means of a scale affixed on to the measuring tube. By using a float with an integrated magnet, optional... [See More]
- Mounting: In-line
- End Fittings: In-line Threaded
- Meter Technology: Rotameter; Variable Area
- Process Media Type: Liquid; Gas
from Orange Research, Inc.
Variable-Area Flowmeters. Our flowmeters are designed for those applications where a rotameter is not appropriate. Consider the inherent problems of rotameters--they are difficult to read, especially with dirty or opaque fluids, have low pressure ratings and allow vertical orientation only. Now... [See More]
- Mounting: In-line
- End Fittings: In-line Threaded
- Meter Technology: Variable Area
- Process Media Type: Gas
from OMEGA Engineering, Inc.
OMEGA ® in-line flowmeters offer high accuracy flow rate indication for oil or water and the ability to either control the flowrate or alarm on high or low flowrates. These units feature an SPDT switch which can be triggered at any point along the flow range. [See More]
- Mounting: In-line
- End Fittings: In-line Threaded
- Pipe Diameter: 0.50 to 0.75
- Process Media Type: Liquid; Gas
from Brooks Instrument
Reliable and affordable, MT3600 metal tube variable area flow meters satisfy the operational and reliability requirements for multiple industrial purge meter applications, such as metering coolants, pump seal fluids, lubricants under pressure and opaque fluids. Featuring high-temperature and... [See More]
- Mounting: In-line
- End Fittings: In-line Threaded; ANSI 150# RF
- Meter Technology: Rotameter; Variable Area
- Process Media Type: Liquid; Gas; Steam
from Malema Sensors
The M-200X Series flow switches are engineered and field tested for sensing increasing and decreasing flow rates of gases or liquids. Pressure variation effects are minimal. This series features such versatility, economy, and accuracy that they can be used in virtually any application requiring... [See More]
- Mounting: In-line
- End Fittings: In-line Threaded
- Pipe Diameter: 0.38 to 0.75
- Process Media Type: Liquid; Gas
from Clark Solutions
The flow meter and switch model DS02 works according to a modified variable area principle. The float is guided in a cylindrical measuring tube by means of a spring. The flowing medium moves the float in the flow direction. A Reed contact is mounted outside the meter in a sealed housing. When the... [See More]
- Mounting: In-line
- Pipe Diameter: 0.25 to 1.00
- Meter Technology: Rotameter; Variable Area
- End Fittings: In-line Threaded
from Brooks Instrument
Need reliable, durable flow measurement in high-pressure, high-temperature or hazardous process settings? The MT3750 metal tube variable area flow meter from Brooks Instrument is your hard-working answer. Constructed from high-strength steel, the MT3750 Series VA flow meter features a compact design... [See More]
- Mounting: In-line
- End Fittings: Compression; In-line Threaded
- Meter Technology: Rotameter; Variable Area
- Process Media Type: Liquid; Gas
from Malema Sensors
The operating principle is based on a free floating magnetic piston which responds only to the motion of fluids within the line, not to static or system pressures. In the presence of fluid flow, controlled movement of the piston actuates an external hermetically sealed reed switch. This switch can... [See More]
- Mounting: In-line
- Pipe Diameter: 0.25
- Meter Technology: Piston
- End Fittings: Flare
from Clark Solutions
The flow meter and switch model DS01 works according to a modified variable area principle. The float is guided in a cylindrical measuring glass by means of a spring. The flowing medium moves the float in the flow direction. The upper edge of the float shows the momentary flow via a burnt-in scale... [See More]
- Mounting: In-line
- Pipe Diameter: 0.25 to 1.00
- Meter Technology: Rotameter; Variable Area
- End Fittings: In-line Threaded
from Malema Sensors
The M-50 Series low flow, flow switches monitor increasing and decreasing flow. They utilize a single moving part which responds to fluid (liquid or gas) flowing within a system. These switches are suitable for a wide range of applications in industrial, biomedical, and OEM products. The flow... [See More]
- Mounting: In-line
- Pipe Diameter: 0.12 to 0.25
- Meter Technology: Piston
- End Fittings: In-line Threaded
from Clark Solutions
The flow meter and switch model DS03 works according to a modified variable area principle. The float is guided in a cylindrical measuring glass. The upper edge of the float shows the momentary flow via a burnt-in scale on the measuring glass. A Reed contact is mounted outside the meter in a sealed... [See More]
- Mounting: In-line
- Pipe Diameter: 0.25 to 1.25
- Meter Technology: Rotameter; Variable Area
- End Fittings: In-line Threaded
from Malema Sensors
The M-60 Series low flow, flow switches monitor increasing and decreasing flow. They utilize a single moving part which responds to fluid (liquid or gas) flowing within a system. These switches are suitable for a wide range of applications in industrial, biomedical, and OEM products. The flow... [See More]
- Mounting: In-line
- End Fittings: In-line Threaded
- Pipe Diameter: 0.25
- Process Media Type: Liquid; Gas
from Clark Solutions
The flow meter and switch model DS04 works according to a modified variable area principle. The float is guided in a cylindrical measuring tube by means of a slotted nozzle. The flowing medium moves the float in the flow direction. An externally mounted pointer indicator is magnetically coupled to... [See More]
- Mounting: In-line
- Pipe Diameter: 0.25 to 1.25
- Meter Technology: Rotameter; Variable Area
- End Fittings: In-line Threaded
from Malema Sensors
The operating principle is based on a free floating magnetic piston which responds only to the motion of fluids within the line, not to static or system pressures. In the presence of fluid flow, controlled movement of the piston actuates an external hermetically sealed reed switch. This switch can... [See More]
- Mounting: In-line
- Pipe Diameter: 0.25 to 0.38
- Meter Technology: Piston
- End Fittings: Flare
from Clark Solutions
The flow meter and switch model DS08 works according to a modified variable area principle. The float is guided in a cylindrical measuring tube by means of a spring. The flowing medium moves the float in the flow direction. An externally mounted pointer indicator is magnetically coupled to the float... [See More]
- Mounting: In-line
- Pipe Diameter: 0.50 to 1.00
- Meter Technology: Rotameter; Variable Area
- End Fittings: In-line Threaded
from Malema Sensors
AD-15/ADI-15/ADT-15 series flow switches can be fitted with local flow indicators. AD series flow switches can be used for monitoring liquid and gas flows. Features. Can be mounted vertically or horizontally. Alarms : Reed switch. Analog Output : 4-20mA transmitter (ADT-15 only). It does not need... [See More]
- Mounting: In-line
- Gas Volumetric Flow Rate: 0.1050 to 141
- Process Media Type: Liquid; Gas
- Electrical Output: Current
from Clark Solutions
The flow meter and switch model DS07 works according to a modified variable area principle. The float is guided in a cylindrical measuring glass by means of a spring. The flowing medium moves the float in the flow direction. The upper edge of the float shows the momentary flow via a burnt-in scale... [See More]
- Mounting: In-line
- Pipe Diameter: 0.50 to 1.00
- Meter Technology: Rotameter; Variable Area
- End Fittings: In-line Threaded
from Malema Sensors
Malema's 2000 series variable area purge meters use a tapered borosilicate glass tube with a fine threaded regulating valve for precise flow adjustment. Various flow tube lengths such as 100 mm, 150 mm and 300 mm are available. It's compact construction with reduced dimensions facilitates easy... [See More]
- Mounting: In-line
- End Fittings: In-line Threaded
- Pipe Diameter: 0.25 to 0.75
- Process Media Type: Liquid; Gas