Hex-Duty Sight Glass – Tough Under Pressure

Up to 400 psi. Ideal for pumps, gearboxes, and demanding systems.

See more, drain smarter – meet the Hex-Duty Oil Sight Glass

The Hex-Duty Oil Sight Glass (OSG) is designed for professionals who demand strength, clarity, and precision in lubrication monitoring. With double the pressure rating of standard models—up to 400 psi—it provides reliable performance in high-stress environments such as gearboxes, pumps, storage tanks, and other fluid-lubricated machinery.

Hex-duty sight glasses

Why choose a hexagonal design?

The unique hexagonal body doesn’t just improve the appearance—it significantly simplifies installation, draining, and disassembly. The shape offers better grip for tools, making maintenance quicker and safer in tight or awkward spaces.

How does the Hex-Duty OSG help manage water contamination?

Water is one of the leading causes of premature wear in lubricated systems. The Hex-Duty OSG allows for immediate visual inspection of both oil clarity and water contamination. Its spring-loaded drain valve makes it easy to purge accumulated water without disassembling the system—saving time and reducing risk. The clear cast acrylic body lets you detect changes in oil quality, trapped water, or sediment at a glance.

Where should the OSG be installed?

The OSG is mounted directly to a drain port at the lowest point of a reservoir. For side-mounted ports, an elbow adaptor can be used. This placement ensures that water and heavier particles naturally settle into the sight glass for inspection and removal.

Key specifications:

Materials: Cast acrylic body, brass nipple and drain valve
Temperature range: –40°C to 93°C (–40°F to 200°F)
Pressure rating: Up to 400 psi

Available configurations:

1 oz bottle with ½” NPT (adaptors available)
3 oz bottle with ¾” NPT (adaptors available)
Optional stainless steel hardware for corrosive environments
Optional magnetic drain valve for detecting ferrous particles

Hex part numbers:

Hex part numbers

Is the Hex-Duty OSG right for your application?

This sight glass is ideal for use on pumps, gearboxes, tanks, and most oil-lubricated equipment. Whether you're in manufacturing, power generation, marine, or heavy industry, the Hex-Duty OSG adds a powerful layer of protection and visual control to your lubrication strategy.

Ready to take control of your lubrication health?

Contact Lubretec