Monolith OSG (Oil Sight Glass)

Oil Sight Glass / OSG / Monolith assists in visual oil inspection.

For optimal visual oil analysis and inspection, using an oil slight glass on your pump can help to avoid a costly repair. This constant bearing iil inspection is made possible with the Monolith design.

In the 1960’s, local California refinery personnel, addressed a need for visual oil inspection in operating pumps and PK Oil Sight Glasses were invented. Since then they have come to be known by many names, sediment glass, sediment bottle, Deb jug, and water finder to name a few. To this day, PK Machine brings you another great design based on the the original. Now you can buy the best Oil Sight Glasses available anywhere, right here.

Used to monitor oil contamination, discoloration and water contaminate level, PK Oil Sight Glasses are:

  • Machined using a single piece of acrylic
  • Optical Grade Acrylic construction
  • Chemically compatible with gear, mineral and synthetic oils
  • Chemical and corrosion resistant
  • Operates to 200 degF and 300 psi
  • Available with multiple brass drain valve options


  • Our oil sight glass will be an early indicator of wear on the bearings, contamination problems and can help find the source of such problems. The oil sight glass alone will not prevent moisture from entering your reservoir or remove any water that has become emulsified in the oil. However, pump inspection on a regular basis using oil sight glasses by PK Machine provide crystal-clear visual inspection of the oil and a magnified view of the presence of sediment. One article published on "The Most Trusted Source of the Latest Reliability & Uptime Maintenance" website reliabilityweb.com describe the importance of the oil sight glass.

    An oil sight glass is also known as sediment bottle, deb jug, and water finder to name a few. To this day, PK Machine brings you the first, the original and the best oil sight glass available anywhere and it is manufactured right here in our machine shop in California.

    Choose the right oil sight glass for you. These are sold in a 12 pack which helps us keep the cost down for you. Please call us if you have any questions at (530)878-4588.