The G21 Tubular Marine Gauge

Heavy duty liquid level gauge, suitable for high pressures/temperatures

Product Description

¹Maximum allowable operating pressure is dependent upon operating temperature and gauge length, contact Seetru for full information

The Seetru Marine gauge is designed for use within the marine and offshore industries. Due to its tubular design, this gauge is suitable only for use with non-flammable liquids. For flammable liquid applications please see either G35 Seemag or G31 Seeflex
This gauge is commonly used for water storage and coolant tanks on board cargo ships, tugs, and military vessels.

The G21 Tubular Marine Gauge

Technical Information for the Seetru G21 Tubular Marine Gauge

  • Maximum Temperature
  • Maximum Pressure
    3.68 Bar¹
  • Valve Materials
    Brass / Stainless Steel
  • Connections
    42mm weld bosses, mild steel or stainless steel Flanged or threaded connections available upon request
  • Seal Materials
    Elastomer O'rings
  • Glass
    Borosilicate glass / BS 3463 Polycarbonate plastic
  • Guard Tube Materials
    Brass / Aluminium / Stainless Steel / Mild Steel
  • Lengths
    To suit requirements (minimum 150mm)
  • Valve Types
    Push button self closing valves,. Valvesless tank return available for top connection


Push-button operation
Except when a reading is being taken, the gauge is permanently isolated from the contents of the tank. To take a reading the spring-loaded valve is opened by pressing a push-button. When released, the connection between the tank and gauge is automatically resealed.

Safe from external damage
Due to the design of the push-button isolation valve, no amount of damage to the gauge or external fittings on the tanks can break the liquid seals. In such an event the fluid cannot escape.

Instant dismantling and re-assembly
The gauge can be removed from the tank for cleaning or servicing while valves remain sealed and the tank remains leak-proof.

Ease of viewing
The level of colorless liquid is indicated by the magnification of a coloured strip on the sight tube.

Where a measure of the precise storage volume is required, graduated gauges can be supplied. The capacity units can either be marked on the guard tube or an engraved scale plate can be provided.

Hydraulic actuation
Hydraulic actuation can be supplied as an optional extra. This is designed to enable both push-button valves to be operated at the same time. Recommend for tall gauges where it would otherwise be difficult to operate the upper and lower push-button valves simultaneously.


Simple Installation and Maintenance:

Choose indicators with straightforward installation features and minimal maintenance requirements. This reduces downtime and streamlines operations.



View or Download the Type G21 Tubular Marine Gauge Datasheet

Full Technical Information

View or Download the Type G21 Tubular Marine Gauge Datasheet

Seetru offers a wide range of downloadable datasheets for our products, including safety relief valves, liquid-level gauges, and sight glasses.  These datasheets provide detailed information on the technical specifications, features, and applications of Seetru products.  They are an essential resource for engineers, designers, and other professionals who need to select the right Seetru products for their specific needs.


Find your PDF Download for the G21 Tubular Marine Gauge below…
Visit our downloads page for other Seetru product brochures and catalogues
Visit Our Downloads Page View the Type G21 Tubular Marine Gauge Datasheet