In the pharmaceutical, chemical and cosmetic processing industries it is important to keep a close eye on piping systems and to understand what is happening inside. Sight glasses, or sight flow indicators, mount onto existing pipe units and provide a valuable window into the world within the piping process. Understanding the different mounting techniques is an important part of determining which sight flow indicator is right for your application.

Flanged sight glasses

  • Can be bolted into place to attach to existing piping units
  • Simplest to install
  • Generally there are pressure limitations to sight glasses which are connected using bolts. Be sure to know the exact operating conditions of your system prior to making a decision.


Weld-on sight flow indicator

  • Since these are welded in place, the vessel they are attaching to needs to be designed and built to the exact specifications to fit the sight glass
  • For obvious reasons, weld-on attachments are rarely added to existing piping systems


Sanitary sight glass

  • Industries such as the pharmaceutical and food processing industries often depend on a sanitary conditions and rely on clamp-on sanitary sight glasses
  • Sanitary sight glasses are easy to remove from the piping system and can be disassembled for cleaning, ensuring the maintenance of a sanitary environment.

Not all sight glasses are created equal and it is essential to understand the exact conditions a sight glass will be operating in. Be aware of any pressure or temperature extremes and choose a sight glass that meets the regulations for a given environment. Keep the system where it will be installed in mind, and know how the sight glass will be used in order to make the correct choice.