80200401 Rev. C - ACR Page 3
2.0 APPLICATION INFORMATION
INLINE FLOW SWITCH APPLICATION
Inline refers to a method of installation for which the flow switch has been designed. This design allows the
process gas to flow through the flow switch assembly and across the heated sensor rather than the probe and
heated sensor being inserted into an existing flow section, pipe, duct, etc.. Inline mounting styles are available
through EPI in sizes from 1/8" pipe through 4" pipe and are provided with threaded NPT ends standard.
Optional end mounting styles may be specified, such as tube ends, tube end fittings, butt weld ends, flanged end
configurations etc. if required. Pipe sizes in excess of 4" require the Insertion mounting style discussed later.
Inline flow switches have the sensing element mounted in place within the flow section. The sensor should not
be removed as the accuracy of the flow signal will be affected. Should it become necessary to remove the sensing
element, the element should be replaced in the same alignment as it was originally positioned. The sensor is
somewhat resistant to dirt and particulate build up (and works well with mild build up). It may become
necessary to clean the sensor from time to time if mounted in extremely dirty environments.
Cleaning the sensor consists of shutting off the flow switch power supply, removing the sensor wires from the
printed wiring board (Note: damage will occur to the sensor if the power supply is not disabled first), removing
the conduit head assembly, backing off the tube fitting nut while holding the sensor in place and carefully
extracting the sensor assembly from the flow section.
The actual cleaning process consists of using a detergent or appropriate cleaning agent (which will not attack the
probe assembly materials of construction) suitable for removing the buildup present on the sensor. A soft brush
should be used to gently clean the sensor surface (Do not press very hard or clean too aggressively, as damage
may occur). After the residue removal is complete, the sensor may be rinsed in water or cleaning alcohol. Make
sure to dry the assembly immediately following the cleaning process. Reassembly consists of reversing the steps
listed above.
INSERTION FLOW SWITCH APPLICATION
Insertion refers to a method of installation process which the flow switch is designed. This design allows the flow
switch assembly to be inserted into the process gas flow section, duct or stack. Consequently, allowing the
process gas to flow across the sensor assembly, rather than the process gas flowing through a flow switch
assembly flow section as in the Inline style flow switch. The Insertion style flow switch probe assemblies may be
inserted into any suitable flow section, pipe, duct, etc.. Insertion styles are available through EPI in sizes from
3/8" tube through 1" tube and require a pipe connection or user supplied bored through tube fitting to mount
them in place. Tube fittings are optionally available from the factory.
Optional ball valve retractor assemblies may be specified to allow removal of the probe assembly and shutting off
process gas leaks at that location during maintenance intervals. Sizes are available in 3/8" through 1" to match
up with the sensor sizes.
Insertion style flow probes were designed to allow the sensing element to be mounted in place within a flow
section, conduit, duct, etc.. The sensor may be removed if calibration or cleaning become necessary. The sensor is
somewhat resistant to dirt and particulate build up and works well with mild build up. However, it may become
necessary to clean the sensor from time to time if mounted in extremely dirty environments.
Cleaning the sensor consists of shutting off the flow switch power supply and carefully removing the flow switch
assembly from the flow section, conduit, duct, etc., and cleaning the sensor.
