Sight Flow Indicator ( Double Window )
A sight Flow Indicator is a device which is inserted in a run of pipe to observe the flow of fluid in the pipe. To enhance the visibility of the flow, spinner is often incorporated in the flow stream so that fluid impinging on the spinner vanes cause it to turn.
Double Window Type Sight Glass (Sight Flow Indicator) in Cast Construction & Fabricated design to meet an industrial requirement of various applications to inspect the process fluid. In Double Window Sight Glass (Sight Flow Indicator) Contains Two Toughened Glasses Mounted opposite to each other. Double Window Type Sight Glass (Sight Flow Indicator) available with various thickness and diameter of glass to suit various applications respects to fluid pressure and temperature. Double Window Type Sight Glass (Sight Flow Indicator) is very easy to replace glass without dismantling the whole Sight Glass assembly from process line.
Introduction of Double Window Sight Flow Indicator
A double window sight flow indicator is a mechanical flow device applied in pipelines to offer visual indication of the liquid or gas flow. It has two transparent viewing windows, typically of toughened glass or acrylic, attached to the opposite sides of the body of the pipe. The design enables the operators to view the fluid on both sides, which gives increased visibility and eases the observation of the existence, color, clarity, and direction of flow of the medium. The indicators find common application in chemical, pharmaceutical, food processing, and petrochemical industries where it is essential to ensure fluid flow in terms of safety, quality control, or operational efficiency. Durability and safety are also enhanced by the double window design since chances of losing complete visibility in case one of the windows is broken are less likely. To emphasize the flow, some models can have a rotating wheel, flap, or drip tube in the chamber to show the flow more easily in colorless or transparent fluids.
Few View Sight Flow Indicator Introduction
A few view sight flow indicators are a kind of flow indicator applied in the pipelines to visually observe the flow of liquids or gases. It is built in such a way that it has more than one observation window or panel that can give a clear view of the medium flowing through the pipeline. These signs are needed in industries where the flow, clarity, or presence of the fluid has to be verified visually.
They find application in process industries like chemical, pharmaceutical, food & beverage, and water treatment plants. The design also makes sure that the operator would have an easy time inspecting flow, whether in low-light conditions or when the pipeline is in a tight spot.
Key Features:
Various viewing windows to increase visibility.
Rugged body (usually of stainless steel or glass).
It is possible to mount it on horizontal or vertical pipelines.
Applicable on clear and light opaque fluids.
Can have rotors, flappers, or balls to indicate motion.
Working
A Double Window Sight Flow Indicator is a form of visual flow indicator which enables one to observe the liquid or gas flowing through a pipeline. It has two transparent viewing windows, on opposite sides of the body, typically toughened glass or borosilicate glass, which are placed in a metallic housing.
Working Principle:
Flow Passage:
The main body of the indicator is usually a straight piece of pipe through which the process fluid passes.
The clear windows enable the operators to have a direct view of the flow in the pipeline.
Two Windows to Clarity and Redundancy:
The two windows allow a clear view on both sides.
This gives an improved observation particularly in low light or cloudy fluid state.
It also provides redundancy so that in case one window is a little obscured or scratched, the other one will still give a view.
Standard Design: No Moving Parts
It is a passive device in most situations, with no moving parts inside.
Certain variants, however, can have flappers or rotors or balls that move with the flow, providing a more direct visual confirmation of flow rate or direction.
Orientation:
Fitted on horizontal or vertical pipes, depending on the design.
Applied to liquids and gases where it is desirable to have visual verification of flow.
Pressure and Temperature Resistance:
Its body is composed of metal materials (such as cast iron, stainless steel, or carbon steel), making it possible to withstand high-pressure and temperature environments.
Applications:
To confirm the presence of flows, clarity, color, and state of the fluid.
Usually found in chemical plants, pharmaceutical industries, petrochemical pipelines, food processing units, and cooling/heating systems.
service of Double Window Sight Flow Indicator
A double window sight flow indicator requires good maintenance to provide long-term performance, visibility, and safety of pipeline operations.
Practices of Routine Maintenance:
Frequent Checkup of Glass Windows:
Examine the viewing windows carefully to see whether they are cracked, scratched, or cloudy.
Change glass in case of visibility to prevent safety.
Viewing Window Cleaning:
Regularly clean both the inner and outer surfaces to eliminate deposits and film or scaling that may occur.
Apply non-abrasive materials and cleaning agents that are compatible with the material.
Seal and Gasket Inspection:
Check gaskets and seals frequently to see that they are not worn out, hardened, or leaking.
Change worn seals as soon as possible to preserve the integrity of the pressure.
Leakage: Check:
Check the body and flange connections to see whether fluid is leaking.
Put the bolts in place and tighten where necessary, but not too tight lest they break the glass.
Flow Indicator verification (provided):
In the case of rotors, flappers, or balls being installed, they should be free to move.
Eliminate all foreign material or sludge that may hinder movement.
Temperature and Pressures:
The operating conditions should not be outside the rated pressure and temperature.
The glass can be damaged by over-pressurization or thermal shocks.
Calibration and Function Testing:
Although sight indicators do not normally require calibration, they should be checked during shutdown or preventive maintenance.
Protective Shielding:
Test the integrity of any protective housing or shield offered to avoid glass-shattering injuries.
Maintenance Frequency:
Monthly: Cleaning and inspection visually.
Quarterly: checks of seal and gasket.
Each year: Complete disassembly and reassembly in critical applications.
service of Double Window Sight Flow Indicator
A double window sight flow indicator requires good maintenance to provide long-term performance, visibility, and safety of pipeline operations.
Practices of Routine Maintenance:
Frequent Checkup of Glass Windows:
Examine the viewing windows carefully to see whether they are cracked, scratched, or cloudy.
Change glass in case of visibility to prevent safety.
Viewing Window Cleaning:
Regularly clean both the inner and outer surfaces to eliminate deposits and film or scaling that may occur.
Apply non-abrasive materials and cleaning agents that are compatible with the material.
Seal and Gasket Inspection:
Check gaskets and seals frequently to see that they are not worn out, hardened, or leaking.
Change worn seals as soon as possible to preserve the integrity of the pressure.
Leakage: Check:
Check the body and flange connections to see whether fluid is leaking.
Put the bolts in place and tighten where necessary, but not too tight lest they break the glass.
Flow Indicator verification (provided):
In the case of rotors, flappers, or balls being installed, they should be free to move.
Eliminate all foreign material or sludge that may hinder movement.
Temperature and Pressures:
The operating conditions should not be outside the rated pressure and temperature.
The glass can be damaged by over-pressurization or thermal shocks.
Calibration and Function Testing:
Although sight indicators do not normally require calibration, they should be checked during shutdown or preventive maintenance.
Protective Shielding:
Test the integrity of any protective housing or shield offered to avoid glass-shattering injuries.
Maintenance Frequency:
Monthly: Cleaning and inspection visually.
Quarterly: checks of seal and gasket.
Each year: Complete disassembly and reassembly in critical applications.
FAQs
A double window sight flow indicator is a piping component that has two transparent glass windows to view the flow of liquids or gases. It is usually applied to determine the presence, clarity, and color of the fluid.
It is commonly applied in chemical plants, power plants, food processing plants, water treatment plants, and the pharmaceutical industry to check and confirm the flow of fluids.
It is used by letting the fluid pass through a chamber that can be observed through two opposing glass windows, allowing one to clearly see the flow, movement, and occasionally even suspended particles or the formation of foam.
The body is usually constructed of cast iron and stainless or carbon steel, and windows are toughened or borosilicate glass. The gaskets and seals are either PTFE, Viton, or rubber-based on fluid compatibility.
Yes, most of the models are built for medium to high pressure and temperature, yet they should always be selected depending on the particular operating conditions and suitability to the process fluid.
A full-view sight flow indicator is a device that gives a 360-degree view of the flowing fluid in a transparent tubular body and is usually fabricated in borosilicate glass or acrylic. It enables one to observe the color, clarity, and state of flow of the fluid.
- Maximum exposure of the process fluid
- Flow presence, bubbles, or contamination can be easily determined through presence or lack of detection.
- Applicable in low-pressure and non-hazardous fluids
- Easy, small, and economical design
It is applied in cooling water lines, process fluid pipelines, filtration systems, and outlets of pumps in industrial sectors like chemical processing, HVAC, food and beverage, and water treatment.
Yes, but only when it is constructed of chemically resistant materials such as PTFE-lined ends or chemically compatible glass. Chemical compatibility should also be checked prior to installation.
- Does not work well in high-pressure or high-temperature applications.
- The glass tube can either break when it is exposed to thermal shock or by mechanical stress.
- It is not ideal where fluids are opaque or dark in color where visual inspection is ineffective.
It is to be visually checked on a monthly basis to ensure that there is no damage to the glass, leakage, or flow blockage, and a thorough maintenance check should be done once a year, according to the operating conditions.
The typical symptoms are cloudy or broken glass, fluid spillage, limited visibility, or inoperable internal gauges (such as rotors or flappers). These indicate that cleaning, replacement of the gaskets, or replacement of the entire unit is required.
Yes, the windows may be washed using non-abrasive chemicals and soft materials. They must be replaced with safety-rated compatible glass following the manufacturer’s specifications in case they are scratched or cracked.
The gaskets and seals must be checked to see whether they are worn, hardened, or attacked by chemicals. They should be changed on a regular basis to avoid leakages and pressure containment, in particular when they are exposed to aggressive fluids.
Always depressurize the pipeline, use proper PPE (gloves, goggles, face shield), and make the area safe against chemical exposure. A pressurized or hot line should never be worked on.
Yes. Metal components such as the body (stainless steel or cast iron) may be recycled as metal, and gaskets and seals are classified as non-metallic industrial waste. Glass parts (particularly borosilicate) typically have special disposal or handling requirements.
Absolutely. To make the disposal or recycling safe for the environment, the indicator should be properly cleaned and decontaminated to eliminate any leftover hazardous or toxic fluids.
In case the unit was working with hazardous fluids, then it should be considered hazardous waste and should be disposed of by a licensed hazardous waste disposal contractor, as required by local environmental regulations.
No. Glass windows are frequently composed of industrial-strength materials (such as tempered or borosilicate glass) that are inappropriate for conventional glass recycling and must be disposed of through authorized industrial waste streams.
Yes, at least in those industries that are regulated (such as chemical or pharmaceutical industries). Disposal records such as cleaning, dismantling, and handover to waste handlers should be kept as records to be audited and complied with.
