1 . Core Concept Decomposition
Flange: This refers to the connection method at both ends of the viewing window. It is secured to the corresponding flange on the pipe with bolts, making installation and disassembly very convenient.
Impeller: This is the most critical functional component of this type of inspection window. It is a compact turbine or impeller installed along the flow path inside the inspection window.
Sight glass : Refers to its observation function. It features one or two transparent panes (typically made of high-temperature and high-pressure resistant glass or plastic), allowing operators to directly observe the flow of media inside the pipeline
2. Working principle
When the fluid (liquid or gas) inside the pipeline flows through the sight glass, it will impact and drive the impeller to rotate. The operator can clearly see the rotation status of the impeller through the mirror window.
3. Main functions and uses
The main function of the flange impeller sight glass is not only to "see", but also to visually judge the flow state of the fluid.
Indicating flow: the most direct function. Seeing the impeller rotating indicates that the medium is flowing; If the impeller does not rotate, it indicates that the flow has stopped.
Estimation of flow rate: Experienced operators can roughly estimate the instantaneous flow rate of the fluid by the speed of impeller rotation (the faster the speed, the higher the flow rate is usually).
Flow direction confirmation: Some specially designed impellers can indicate the flow direction of the medium.
Application scenarios:
Confirm whether the pump is working properly at the inlet and outlet of the water pump.
Confirm whether the circulation is established for the cooling water system and lubricating oil system.
Used for visualizing and monitoring the transportation of process fluids on production lines in industries such as chemical, pharmaceutical, and food.
4. Main features
Intuitive and clear: providing the most direct and reliable flow indication.
Simple structure, high reliability: mechanical structure, no need for power supply, low failure rate.
Easy maintenance: flange connection, convenient for quick disassembly, cleaning or component replacement.
Pressure and temperature resistance: Windows and seals are usually selected according to working conditions and can adapt to certain pressures and temperatures.
5. Differences from other types of mirrors
Difference from ordinary straight through mirrors:
A regular sight glass can only allow you to see if there is a medium in the pipeline (such as seeing that the liquid is full), but cannot determine if it is flowing (especially when it is a transparent liquid).
The impeller sight glass clearly indicates the flow state through the rotation of the impeller, with stronger functionality.
Difference from flow meter:
A flowmeter is a measuring instrument designed to accurately measure the volume or mass flow rate of a fluid and provide specific numerical readings.
The impeller sight glass is a visual indicator mainly used for qualitative judgment (presence/absence of flow, fast/slow), and cannot provide accurate flow data. It is simpler and cheaper.
