Oil Level Indicator (OLI)

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. The OLI is a clear acrylic tube with ½” NPT threads at each end. Red and green Buna O-rings 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 optional breather* at the top ½” NPT port as seen on the Esco Oil Sight Glass and Level Monitor. If the user requires a closed loop, the ½” NPT can be used as a connector port to feed back into the system. Operators can visually monitor the oil for dirt and debris and take appropriate preventive action.

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Why use an old style vented oil gage that is difficult to see through and has breakable glass, when you can install a crystal clear, strong acrylic Esco Oil Level Indicator that offers 360° of oil viewing?

Old Style Vented Sight Gauge                           Esco Oil Level Indicator       


*Breather Part number for OLI3 – OLI12:  ESBCAP
*Breather Part number for OLI15 – OLI30: ESND2

Maximum PSI 225

*Operating Temperatures and Pressures:  180°F to 265 PSI, 203°F to 66 PSI, 230°F at atmospheric pressure

12 Item(s)

per page

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Oil Sight Glasses - Oil Level Indicator (OLI)
Product Price Dimensions  

OLI - 3" Male, 1/2" NPT

Part #: OLI3

$36.52
.875" OD, 3" L

OLI - 6" Male, 1/2" NPT

Part #: OLI6

$41.11
.875" OD, 6" L

OLI - 9" Male, 1/2" NPT

Part #: OLI9

$46.23
.875" OD, 9" L

OLI - 12" Male, 1/2" NPT

Part #: OLI12

$50.82
.875" OD, 12" L

OLI - 15" Female, 1/2" NPT

Part #: OLI15

$117.64
1.75" OD, 15" L

OLI - 18" Female, 1/2" NPT

Part #: OLI18

$138.37
1.75" OD, 18" L

OLI - 21" Female, 1/2" NPT

Part #: OLI21

$154.42
1.75" OD, 21" L

OLI - 24" Female, 1/2" NPT

Part #: OLI24

$176.28
1.75" OD, 24" L

OLI - 27" Female, 1/2" NPT

Part #: OLI27

$198.15
1.75" OD, 27" L

OLI - 30" Female, 1/2" NPT

Part #: OLI30

$226.70
1.75" OD, 30" L

Breather for OLI sizes 3" - 12"

Part #: ESBCAP

$12.10
1/2" NPT

Breather for OLI sizes 15” - 30”

Part #: ESND2

$24.09
3/8” NPT

12 Item(s)

per page

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