E-Zine March 2009
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All-Welded Vortex Shedding and Fluidic Flowmeters
Many vortex shedding and fluidic flowmeters are assembled using seals, O-ring or gaskets to prevent the fluid from leaking out of the flowmeter.
In contrast, all-welded flowmeter designs reduce the number of potential leak paths by not using any seals, O-rings or gaskets.
In doing so, leak paths are generally limited to the piping connections and welds.
All-welded designs are generally preferred when a potential hazard can be created by fluid leakage.
Low Flow Vortex Shedding and Fluidic Flowmeters
At low flow rates, achieving sufficient Reynolds number to operate vortex shedding and fluidic flowmeters can be an issue.
Some vortex shedding and fluidic flowmeters are designed can measure these relatively low flows in pipes that are generally under 15 mm (0.5 inch).
High Flow Vortex Shedding and Fluidic Flowmeters
At high flow rates, the frequency of oscillation of vortex shedding and fluidic flowmeters becomes so low that it can reduce response time and become an issue for the flowmeter electronics.
Some vortex shedding and fluidic flowmeters are designed to measure flow in pipes that are 250 mm (10 inch) and larger.
Metal (Other Than CS/316SS) Vortex Shedding and Fluidic Flowmeters
Due to the cost and general applicability of carbon steel and 316SS, most metal vortex shedding and fluidic flowmeters were designed and are constructed using these materials of construction.
However, to increase the applicability of the technology, vortex shedding and fluidic flowmeters can be constructed using other metals, most notably Hastelloy.
Note that some vortex shedding and fluidic flowmeters have seals that are constructed from non-metallic materials.
Therefore, the availability of a vortex shedding and fluidic flowmeter made of materials other than carbon steel and 316SS does not necessarily imply that the seals are (or can be) constructed of a material that is compatible with the process.
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Excerpted from Excerpted from The Consumer Guide to Vortex Shedding and Fluidic Flowmeters
ISSN 1538-5280
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