Oil Level Indicator

SKU: oil-level-indicator

Quick Overview

The Oil Level Indicator (OLI) is a is a clear acrylic tube with 1/2” NPT threads at each end for lengths 3” to 15”. Red and green decals are included with the OLI to mark upper and lower limits, or to designate running oil level and idle oil level. It can be installed with the 1/2” ESBCAP optional breathers or if the user requires a closed loop, the 1/2” NPT can be used as a connector port to feed back into the system. See below for product details, specifications, temperature and pressure ratings and size and part number chart.

Price from:
As low as $41.82

The Oil Level Indicator (OLI) was developed in response to the need of maintenance professionals to gauge the oil level inside large tanks, gearboxes and reservoirs. When water contamination is not a problem or when a regular Esco Oil Sight Glass is already installed at the drain port, the Oil Level Indicator can be utilized to monitor oil level.  Made to replace the brass and glass sight gauges that stain and leak, the OLI is built to last.


Pumps, gearboxes, storage tanks


  • Red and Green Decals included to mark running and idle oil levels
  • Top has NPT thread for optional 2 micron breather or adaptor for closed loop systems
  • Breathers are not included and must be purchased separately
  • See FAQs  for more information

Operating Range

  • 180º F to 265 PSI
  • 203º F to 66 PSI
  • 230º F at atmospheric pressure
  • -40º F minimum low temperaure
Oil Level Indicator
Dimensions Part #
OLI - 3" Male, 1/2" NPT
0.875" OD, 3" L OLI3
OLI - 6" Male, 1/2" NPT 0.875" OD, 6" L OLI6
OLI - 9" Male, 1/2" NPT 0.875" OD, 9" L OLI9
OLI - 12" Male, 1/2" NPT Ends 0.875" OD, 12" L OLI12
OLI - 15" Male, 1/2" NPT .875" OD, 15" L OLI15

*For lengths greater than 15, please Contact Us for custom and additional hardware options.

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