
Product
Tubular Oil Level Indicator
A direct-reading tubular indicator for visually monitoring oil levels in hydraulic reservoirs, lubrication tanks, gearboxes, and other industrial equipment.
Technical Specifications
| Product Type | Tubular Oil Level Indicator |
|---|---|
| Indication Method | Direct visual level indication |
| Installation Position | Vertical |
| Mounting Type | Side-mounted threaded connection |
| Body Material | Brass, carbon steel or stainless steel |
| Sight Tube Material | Borosilicate glass |
| Protective Tube | Metal guard with viewing slot |
| Seal Material | NBR, FKM, EPDM or silicone |
- Standard and custom specifications are available.
- Drawing and sample-based customization is supported.
Oil Level Indicator
Product Description
The Tubular Oil Level Indicator is designed for simple and reliable visual monitoring of liquid levels in oil tanks and industrial equipment. It is commonly installed vertically on hydraulic reservoirs, lubrication systems, gearboxes, compressors, machine tools and small storage tanks.
The indicator operates according to the communicating-vessel principle. Oil enters the transparent tube through the lower threaded connection, and the liquid level inside the tube corresponds to the level in the connected tank. This provides operators with a continuous, direct indication without electricity, sensors or electronic displays.
A metal body and protective outer frame help support the transparent tube and reduce the risk of accidental impact. The open viewing slot allows the oil boundary, condition and approximate colour to be inspected during routine equipment checks. A graduated scale can also be added when a more convenient level reference is required.
Depending on the installation conditions, the indicator can be manufactured with carbon-steel, stainless-steel or brass fittings. Thread types, tube lengths and sealing materials can be selected to match the reservoir connection and the chemical compatibility of the oil.

This type of indicator is primarily intended for atmospheric or low-pressure oil reservoirs. The acceptable working pressure and temperature depend on the tube, body, seal and connection configuration and should be confirmed before ordering.
Typical applications include:
Hydraulic oil reservoirs
Lubrication oil tanks
Industrial gearboxes
Air compressors
Machine tools
Pump lubrication systems
Generator and auxiliary fuel tanks
Low-pressure storage vessels
Direct-reading tubular gauges are widely described as an economical solution for low-pressure tanks, while commercial designs commonly offer threaded connections, protective metal bodies and customized measuring lengths.
Technical Specifications
Size
Standard and custom sizes are available to suit different tank capacities and installation spaces.
Overall length: commonly available from approximately 3 to 12 inches (76–305 mm); other lengths can be produced upon request.
Visible length: determined by the required oil-level monitoring range.
Tube diameter: selected according to the indicator length and working conditions.
Thread size: commonly available in 1/4", 3/8", 1/2", 3/4" and 1".
Thread standard: NPT, BSP, BSPT, G, ZG or metric thread options.
Connection direction: side, bottom or other configurations can be produced according to the installation drawing.
Scale: plain tube or graduated scale options are available.
Comparable industrial products are offered in 3", 5", 7", 10" and longer configurations, with both imperial and metric mounting or connection options.
CUSTOM MANUFACTURING
Need a Custom Size or Specification?
Send your drawing, sample, dimensions, material requirements, operating temperature, pressure and process medium. We will review the application and confirm the suitable product specification before production.
Standard products and OEM/ODM solutions available.
QUICK INQUIRY
What to Send Us
To receive an accurate recommendation and quotation, include as much of the following information as possible.
- Product name or drawing/sample
- Required dimensions and quantity
- Material or applicable standard
- Operating temperature and pressure
- Process medium and installation details
Inquire About: Tubular Oil Level Indicator
Fill in your contact details and requirements. Our team will respond within 24 hours.