What is the proper procedure for returning a gauge glass to service after installing a new glass?

The proper procedure for returning a gauge glass to service after installing a new glass involves first opening the drain and then cracking open the top valve. This approach ensures that any air trapped in the gauge glass is safely vented out through the drain, preventing potential pressure buildup or damage to the newly installed glass.

By cracking open the top valve after opening the drain, you allow the system to gradually fill the glass with the fluid while simultaneously venting any air. This method is essential for preventing the risk of air pockets, which can lead to inaccurate readings or even breakage of the glass due to unequal pressure. Properly managing the pressure in this way ensures that the gauge operates effectively and safely after maintenance.