Flow Indicators
Flow indicators, often called sight flow indicators, are components of industrial process lines that allow an operator to view the liquid as it moves through the pipes. They are types of flow meters that monitor fluid clarity, fluid level and color through an observation window. Flow indicators are used mostly in industrial and manufacturing applications where flowing liquid is part of a process. They are made of metal or plastic and a glass or transparent plastic window, which can be small or full view, where the liquid is seen from different viewpoints. For low visibility, flow indicators may contain lights. These indicators are attached to the piping system by threaded, flanged or butt welded connection, all of which must be waterproof.
There are various types of flow indicators, depending on the type of liquid and what exactly about it is being monitored. Plain sight indicators are the simplest option, containing only an observation window. No moving parts are used, and this type is only for easily visible fluids. Visual indicators use floating balls, flappers and propellers. The floating balls indicate the liquid level in hard-to-see applications as an alternative to lights. Flappers are used when the flow of the liquid could 2 different ways. It lets the observer know the flow direction. Propellers are used for clear or transparent liquids to determine whether or not they are flowing.