Longitudinal sight glasses for direct level monitoring in containers, boilers, tanks, and silos
Vertical sight glasses are used for the safe visual inspection of liquid levels in closed containers, boilers, tanks, silos, and equipment.
At ACI, you will find a variety of models designed for welding-in or welding-on applications, suitable for various pressure ratings, temperatures, and installation scenarios.
The product range includes standard models for industrial plant engineering, as well as variants with enlarged viewing ports and solutions designed for higher pressure requirements. This allows the appropriate longitudinal sight glass to be specifically tailored to the tank, the fluid, and the operating conditions.
If no suitable standard model is available, we will work with you to develop a suitable solution.
Level indicator for working pressures up to 40 barg
Level indicator for working pressures up to 3 barg
Level indicator for working pressures up to 3 barg
Level indicator for working pressures up to 6 barg
Level indicator for working pressures up to 25 barg
Level indicator for working pressures up to 16 barg
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Technical Diversity for Industry and Plant Engineering
ACI’s longitudinal sight glasses include a variety of longitudinal sight glass fittings for reliable level monitoring in vessels, tanks, silos, and equipment.
Depending on the installation situation, pressure rating, and temperature, various designs are available for industrial applications—ranging from classic fittings for welding-in or welding-on to variants with larger viewing ports and solutions for higher pressure ranges.
For many applications, the cost-effective Type 330 is suitable as a proven standard design for operating pressures up to 40 bar gauge. The longitudinal sight glass is primarily used for level monitoring.
Especially in applications with lower operating pressures, a larger viewing aperture can be a decisive advantage. For lower pressure requirements, the Type 334 and Type 335 offer lighter variants for operating pressures up to 3 bar gauge. They are particularly suitable where clear visibility of the fill level and additional process monitoring are required.
For higher pressure ratings, ACI offers, among others, the Type 338 for operating pressures up to 16 bar gauge. This allows the appropriate model to be selected based on the vessel, medium, and pressure range.
Materials and design according to requirements
The selection of a suitable longitudinal sight glass depends not only on the design but also on the medium, pressure, temperature, and installation conditions. Often, multiple longitudinal sight glasses are welded in a staggered pattern to monitor tall vessels.
Depending on the application, different types of glass and materials are used, including borosilicate glass per DIN 7080, soda-lime glass per DIN 8902, or quartz glass, as well as tailored stainless steel and seal designs.
Depending on the application, longitudinal sight glasses can be adapted to the respective process conditions with additional protective and special designs. These include, among other things, glow protection screens for thermally stressed applications. FEP or Halar® coatings are used for chemically demanding media, such as caustic solutions like sodium hydroxide.
Technical consultation to help you choose the right design
In more demanding operating conditions, a standard solution is often insufficient. Precise technical design is crucial, especially when dealing with elevated temperatures, specific pressure ranges, custom lengths, or application-specific requirements for materials and seals. ACI can assist you in selecting the appropriate longitudinal sight glass for your system.
Frequently Asked Questions About Longitudinal Sight Glasses
The most important factors are pressure, temperature, the fluid, the installation conditions, the overall length, and the desired viewing aperture. Materials, seals, and any special designs should also be tailored to the specific application.
Yes. Depending on the model, options include FEP or Halar® coatings, glow protection screens, high-temperature models, low-temperature models, and custom designs.
Depending on the application, materials such as borosilicate glass, as well as specially designed stainless steel and sealing components, are used. The appropriate combination depends on the medium, pressure, temperature, and installation conditions.
Yes. Various models are available within the product range for higher pressure ratings. The appropriate design depends on the pressure range, installation conditions, and process requirements. If no suitable standard solution is available, we will work with you to develop a suitable solution.
For lower pressure requirements, ACI offers, among others, the Type 334, Type 335, and Type 336. These models are particularly suitable for applications with lower operating pressures where a clear view of the fill level and simultaneous process control are desired or essential.
Vertical sight glasses are used for visual inspection of liquid levels in closed containers, tanks, silos, and equipment. They allow for quick and reliable reading of the liquid level directly on the container.