Sight Flow Indicators with flappers are recommended for horizontal pipelines with up ward flow. Arem Engineers manufactures Sight Flow Indicators with flappers.
Arem Engineers also manufactures wide range of industrial valves, strainers, gauges and other allied products. Sight Flow Indicators with flappers are suited for transparent or slightly opaque solutions and are also used for gases. One important use of this flow indicator is in pipelines, where a down stream valve may be closed due to some human error.