Normally Open (NO) Volumetric Gas Flow Switches
Last Updated: April 1, 2025
Description
Normally Open (NO) Volumetric Gas Flow Switches are devices designed to monitor and control the flow of gas within a system. In their default state, these switches do not allow current to pass through until they are activated by a change in flow conditions. They are integral components in systems where maintaining specific flow parameters is crucial.
Working Principle
Normally Open (NO) Volumetric Gas Flow Switches operate by sensing the flow of gas through a valve contained within the switch. When the flow reaches a predetermined level, the switch "makes" contact, allowing current to pass through and triggering a response, such as turning a pump or valve on or off. This mechanism is useful for maintaining proper system flow and for identifying potential issues within the system by monitoring flow characteristics such as volume, speed, and pressure .
Applications
These switches are commonly used in HVAC systems to ensure proper air and steam flow. They can also be found in industrial gas distribution systems where precise flow control is necessary to maintain safety and efficiency. Specific examples include their use in gas-fired boilers to monitor and control the flow of natural gas, ensuring optimal combustion and energy efficiency.
Advantages over other Volumetric Gas Flow Switches
Normally Open (NO) switches offer the advantage of not consuming power in their default state, which can be beneficial in systems where energy efficiency is a priority. Additionally, their ability to remain inactive until a specific flow condition is met reduces wear and tear, potentially extending the lifespan of the switch compared to normally closed (NC) switches that are always active until deactivated .
Limitations
One limitation of Normally Open (NO) Volumetric Gas Flow Switches is that they require a specific flow condition to activate, which may not be suitable for systems that need constant monitoring or immediate response to flow changes. Additionally, they may not be ideal for applications where the flow conditions are highly variable or unpredictable, as this could lead to delayed activation and response times.
Considerations
When selecting Normally Open (NO) Volumetric Gas Flow Switches, it is important to consider factors such as initial costs, operating expenses, and durability. These switches may have lower operating expenses due to their energy-efficient design, but initial costs can vary depending on the complexity and specifications required for the application. Durability is another key consideration, as the materials used in the switch must withstand the operating temperature and pressure of the system. Additionally, maintenance and replacement costs should be evaluated, as these can impact the overall cost-effectiveness of the switch over its operational life .
from Fluid Components Intl. (FCI)
The FS10A is a universal flow monitor and switch specifically designed for gas and liquid process analyzer sampling systems. The FS10A is a fast responding, highly repeatable sensor which installs easily into a standard tube tee fitting or new SP76 (NeSSI) modular manifold. The FS10A utilizes proven... [See More]
- Normal State: Normally Open
- Pipe Diameter: 0.25 to 0.50
- Meter Technology: Thermal
- Mounting: Insertion
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]
- Normal State: Normally Open; Normally Closed
- Mounting: Insertion
- Meter Technology: Thermal
- End Fittings: In-line Flanged
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]
- Normal State: Normally Open; Normally Closed
- Pipe Diameter: 0.75 to 1.00
- Meter Technology: Thermal
- Mounting: In-line
from ifm electronic gmbh
Air gap provided as absolute value. Precise values at all times thanks to pressure-compensated measuring principle. Enables zero gap and clogging detection. Self-cleaning measuring channel even resists purge air pressure. Easy teaching of thresholds with just one click. Convenient operation via... [See More]
- Normal State: Normally Open
- Process Media Type: Gas
- End Fittings: In-line Threaded
- Operating Pressure: 232
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]
- Normal State: Normally Open; Normally Closed
- Mounting: In-line
- Meter Technology: Rotameter; Variable Area
- End Fittings: In-line Threaded
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]
- Normal State: Normally Open; Normally Closed
- Mounting: In-line
- Pipe Diameter: 0.75 to 12.00
- End Fittings: In-line Threaded
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]
- Normal State: Normally Open
- Pipe Diameter: 0.25 to 1.00
- Meter Technology: Rotameter; Variable Area
- Mounting: In-line
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]
- Normal State: Normally Open
- Pipe Diameter: 0.25 to 1.00
- Meter Technology: Rotameter; Variable Area
- Mounting: In-line