Sight glasses are essential for safe and effective operations in many industries, including chemical, food, and pharmaceutical applications. Countless engineers and site managers rely on these transparent tubes or windows in their day to day work. But what exactly are sight glasses, and why are they used?
Below we explain how these parts work, explore some typical applications, and advise on what to consider when choosing your sight glasses.
What are sight glasses, and how do they work?
Sight glasses are robust components that allow workers to observe inside enclosed machinery without interrupting processes or stopping operation. They typically feature a small glass window to look through, similar to an eyepiece.
There are a few different reasons why you may want to install and use a sight glass, depending on your application. You could need to monitor system pressure or the amount of gas or liquid within a machine at a critical point.
Doing so can help workers monitor changes and spot potential problems to ensure equipment runs efficiently and safely.
Where are sight glasses used?
Sight glasses are commonly used for monitoring pneumatic systems, making them ideal for several industrial settings such as:
- Chemical plants
- Food and drink factories
- Pharmaceutical factories
- Wastewater treatment and management works
Companies monitoring fluids to control quality and safety can range from petrochemical producers to craft beer breweries. Specific liquid level gauges may be used in these cases.
Utilities, food and beverage, and even dry cleaning companies use sight glasses to observe pressurized systems such as steam boilers. Specific boiler sight glasses can be essential for ensuring user safety, given the well-documented risk of explosion.
For industries that use heat or heat transfer, sight glasses ensure pilot lights and other heating elements are functioning correctly without an operator needing to look directly inside.
Choosing the right sight glasses
These components come in various shapes and sizes to suit different applications. Consider the specific machine or system you will be used in. Your ideal sight glass will need to be constructed in a way that resists the materials, fluids, and temperatures it will be subjected to without degrading or restricting its usability.
Sight glasses are commonly made from aluminum, stainless steel, or brass, while the transparent viewing point might be constructed from Pyrex or various other glass types.
Each material will perform slightly differently in certain conditions, so it’s important to consider your needs regarding corrosion, pressure, and heat resistance. You could buy a sight glass kit or individual components.
Whatever your requirements or preferences, look to a reputable brand to ensure your sight glass meets industry performance and safety standards.