the BOSS oil sight glass

Our Premium One-Piece Oil Sight Glass

The SAE ORB connections eliminate overtightening and extend operating range. Meets & exceeds new API and refinery standards.

  • Eliminates overtightening with shouldered SAE O-ring boss connections to the body 
  • Extends operating range to 600 psi
  • Improved durability and compact design Same single piece body construction Compact ultra-durable design

Problem:  Overtightening of the standard NPT threaded sight glass

Solution:  Mitigate the ability to over-tighten with a connection change-

What customers say:

Major Refinery Reliability manger


"Once you see it, it’s a no brainer."

The use of an SAE ORB (O-Ring Boss) connection on the sightglass with a metal fitting to the NPT machine connection (See diagrams below).  The ORB solution provides a shouldered o-ring seal at the sightglass (acrylic) and a metal NPT connection to the machine oil reservoir. 

This threaded positive mechanical connection which prevents over-tightening of the metal fitting to the acrylic sightglass, and allows the use of a tool (wrench) for tightening metal fitting to the equipment reservoir.  These SAE ORB fittings are very common and standardized connectors in hydraulic systems, heavy equipment, automotive, etc. 

In addition, this fitting connection change extends the operating range to 600psi with improved durability and compact design.