What is A Sight Flow Indicator？
The use of the sight flow indicator of BCST is helpful in pipes and facilitating 360-degree observations regarding the flow of the materials. There are two glasses in circular shape whose position is perpendicular towards the direction of the flow and opposite to the other one. Here are the details regarding the sight flow indicator’s accessories, types, and working.
The sight flow indicator is the device whose installation is in the pipe for providing the visuals regarding the verification of the flowing liquid in terms of direction and accuracy. The sight flow indicator helps the operators observe the liquids’ colour and clearness from the window. The body of sight flow indicator consists of more than 1 window, gaskets, and connections. A sight flow indicator is suitable for those pipes whose size range is from ¼ inches -16 inches. You can observe directly from the sight flow indicator without any false or impossibility to read. There is also the possibility of applying a sight flow indicator at any cycle of movement no matter it is powder, solid, or liquid. The workers of sight flow indicator can see the approx: flowing rate, condition, and direction of the flow without causing any interruption in the process.
What are the types of sight flow indicators?
360 degrees flow indicator:
You can also name the cylindrical, full-view, or tube-style flow indicator. In this type of sight flow indicator, the fluid passes from the glass cylinder that you can see from all the angles. It permits a sufficient amount of light for the lightening of the flow. This situation is ideal for the flowing fluid of the process for different conditions such as foam, colour, clarity, and the existence of moisture. The styling of the sight flow indicator is suitable for systems where there is low pressure, and the flow rate is moderate. You need to install these indicators on the pipes where the mechanical stress is minimum. As the substitute design, there is also a metal shield or sheath along the windows. It helps provide the indicator’s power and protects it from mechanical stress. The fitting of the 260 degrees flow indicator is along with the glass and marking of the calibration scale. You can use it for indicating the levels.
Flutter indicator:
If you want to observe the liquids and gases in the Teflon lining, then you can select the flutter indicator. You can see the thin ribbon moving without reacting with the material like Teflon from the sight glass window. The intensity of the flutter shows the speed of the flow. Mostly, its mounting is in the sight flow indicator in such a manner that the usability of the flutter indicator is only in one direction. It is due to the small mass of the ribbon, and its movement is effortless. Moreover, the flutter indicator is ideal for slow-speed processes and light-process medium.
View-through flow indicator:
There are two windows in opposite directions in the view-through flow indicator to see the flow of the fluid from the back. It is different from 360 degrees flow indicator as this type is for harsh and high-temperature applications. This type of indicator is available with Teflon lining on the metal body for corrosion purposes. The types of mounting include clamp, socket-weld, flange, and threaded. The sizes depend on the manufacturer, but it is ¼ inches to 16 inches diameters. There is also the availability of large-size units due to the specification of the order. The range of the pressure rating is from 20 to 3000 psi. This styling includes many applications and can fix them with indicating devices, including balls, motors, flutters, flappers, and drip rubes. Mostly, neither the view-through nor full-view sight flow indicator is not precisely according to the requirements of the applications. For the unusual sizing and requirements, the suppliers offer the customization of the indication or change the standard units.
Ball flow indicator:
The flowing medium moves the ball from the indicator’s base and takes it at the top of the window. You can see the ball from the window, so the flow is visible at a single glance. The suspension of the ball through the flow indicates the medium’s existence. It is due to return the ball to its resting position. This styling of the indicator is applied to the vertical pipes flowing in the upward direction. Generally, the ball flow indicator is helpful, along with the low speed of liquids and gases. One more type of ball indicator is where the flow of processing fluid or gas makes the ball oscillate in the dome of glass. Whenever the medium stops flowing, the ball drops. You must install the ball flow indicator in the horizontal direction. This is particularly useful where the fluids and gases have fast speed. There is also an availability of a plastic ball flow indicator along with the calibration marking to show the flow. As the recommendation, it is not an excellent choice to use plastic indicators for processing applications. There is also an availability of 90 degrees models where you can’t use the straight-line sight flow indicator.
Flapper flow indicator:
You can fit the flow indicator with the hinged flapper or flag visible from the sight glass. The deflection of the flapper is towards the direction of the flow. Because there are changes in the position of the flapper along with the relation of the force of the flow, this facilitates the user with the estimated gauge of the flow. This style is best for the pipelines in horizontal directions. But you can install it in the horizontal direction and the upward flow. It is the best choice for the gases; solutions are transparent and have no requirement of direct observations.
Drip indicator:
The drip indicators are the models for observing the drips and installation on the drip tube. The observation of the drips is helpful in different processes like distillation. Because there is the use of gravity, the drip indicators are usually applied on the vertical pipes along with the flow in a downward direction. There are few applications where there is the possibility of horizontal installation.
Visual flow meters:
It is a flapper kind of sight flow indicator where the flapper consists of resetting the spring. The force applied by the spring overcomes by the flow of the processing fluid. There is a scale marking on the glass to indicate the flow. In simple applications, you can use a visual flowmeter as a substitute. Some of the sight flow indicators use the flapper or flag to show the flow’s volume through the position of the scale marking on the sight glass. The factory set these flowmeters for the particular flow of water at 20 degrees Celsius designed for the specific diameter of the pipe. The visual flowmeters aren’t applicable for non-water applications. Its working is in the single direction only.
Rotatory flow indicator:
You can fit the flow indicator and the rotor that keeps turning from the gas or liquid flow. The mounting of the rotor is on the window, so it is easy for the user to observe the estimated speed and direction of the flow. It is specifically helpful for cleaning gases and liquids. But you can see the rotor even there are dark fluids. This indicator works in any direction and position. There is no possibility of using this indicator when there is a low flow rate because the rotatory device is unable to turn.
