Flange sight glass is an observation window installed on pipelines, containers, or equipment, used for real-time monitoring of the flow status, color changes, liquid level height, bubbles, or impurities of internal media (liquids, gases, or powders). It is widely used in industries such as chemical, petroleum, pharmaceutical, food, electricity, water treatment, etc.
1. Structure and composition of flange mirror
The flange mirror is mainly composed of the following components:
Mirror glass (lens)
Material: Tempered glass, borosilicate glass, quartz glass, mica glass, etc., with characteristics of high temperature resistance, pressure resistance, and corrosion resistance.
Shape: circular, square, some mirrors have scales or lighting functions.
Flanges (flange connectors)
Material: Stainless steel (304/316), carbon steel, PP plastic, etc., selected according to the medium environment.
Connection method: flange standard (such as HG/T 21575, ANSI, DIN, JIS, etc.).
Sealing gasket
Material: PTFE (polytetrafluoroethylene), rubber, graphite gasket, etc. to ensure sealing.
fastener
Bolts and nuts (usually made of stainless steel) are used to secure flanges and mirror glass.
2. Main types of flange sight glasses
According to different working conditions, flange mirrors can be divided into the following common types:
Type, characteristics,
Ordinary flange sight glass: standard structure, suitable for general working conditions (low pressure, room temperature).
Pressure resistant flange sight glass: made of thickened glass or tempered steel, suitable for high-pressure pipelines (such as PN16-PN40).
Explosion proof flange sight glass: equipped with metal protective mesh or explosion-proof film, suitable for flammable and explosive environments (such as the petrochemical industry).
Illuminated flange mirror: Built in LED or fluorescent lighting for easy observation in dark environments (such as reaction vessels and storage tanks).
Flange mirror with flushing port: equipped with a cleaning nozzle, can regularly flush the mirror surface to prevent scaling (such as in sewage treatment and food industry).
Four way mirror (multi-directional mirror) with multiple viewing directions, suitable for complex pipeline systems.