Sight glass

A sight glass is like a little window that lets you see what's going on inside a machine or a tank without having to open it up. It's kind of like the peephole in your front door, but for bigger things.

Let's pretend you have a giant container filled with water. You want to know exactly how much water is inside, but you can't just open it up and look. That would be a big mess, and you might get wet! Instead, you can install a sight glass on the side of the container.

The sight glass is usually a small, clear tube made of sturdy material like glass or plastic. It's attached to the container using special fittings that make it leak-proof. When you look through the sight glass, you can see the water level inside the container.

Some sight glasses have markings or measurements on them, kind of like a ruler. This makes it really easy to see if the level of the water is going up or down.

Sight glasses are used in lots of different industries, like in factories that make food, medicine, or chemicals. They are also used on big machines like boilers, where it's really important to monitor the water level to make sure the machine is working safely.

Overall, a sight glass is a very useful tool that lets you see inside things without having to open them up. It's kind of like having x-ray vision, but for machines instead of people!