• Introduction

Tubular level gauges are simple yet highly effective instruments used for the direct observation of liquid levels within low to medium-pressure tanks and vessels. They operate on the principle of communicating vessels, where a transparent glass or plastic tube is connected to the side of a container via valve heads, allowing the liquid to find its own level within the tube to match the height of the fluid inside the tank. These gauges are often protected by a metal shroud or guard rods to prevent mechanical damage and typically feature offset needle valves or ball-check valves that automatically shut off the flow in the event of tube breakage to ensure operational safety.

  • Working Principles

The working principle of a tubular level gauge is based on the hydrostatic law of communicating vessels, which dictates that a liquid in interconnected containers will maintain a uniform level regardless of the vessels’ shapes. The gauge consists of a transparent tube mounted externally to the tank, connected at both the top and bottom through isolation valves. As fluid enters the tank, it simultaneously flows into the tube until the liquid level in the glass matches the height of the fluid inside the vessel. This provides a continuous, direct visual representation of the tank’s contents, allowing operators to monitor levels in real-time. To ensure safety, these instruments often incorporate safety ball-check valves that automatically seal the connection if the tube breaks, preventing hazardous leaks or pressure loss.

  • Applications

Tubular level gauges are versatile instruments widely used in various industries where direct visual monitoring is required for non-hazardous or moderately pressurized liquids.

Here are the primary applications of tubular level gauges:

  • Water and Wastewater Treatment

  • Oil and Gas Industry

  • Chemical Processing

  • Boiler and Cooling Systems

  • Food and Beverage

  • Pharmaceuticals

  • General Manufacturing

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Boiler Steam Water Level Gauge

In stock

SKU: SEL
The Boiler Steam Water Level Gauge Model SEL indicates level status from the display equipment by identifying electric resistance of water and steam by electrode sensors. The level of water portion displays each level in green and the steam portion displays it in red on the indicator of the micro processor controller unit (MPU) installed at site and the remote indicator unit (RIU) in control room etc. A SEL-S series Level Switch installed on the drain port in the superheated steam line will detect the level of condensed water in the port. - Detection of level and status for water and steam in boiler drums and steam generators - For high temperature & pressure - On site (local MPU) and remote (Computer or RIU) indicators - 10 set point alarms, changeable - Level gauge, transmitter, switch function in one device - Battery backup (opt.) download pdf datasheet
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Level Indicator ELD

In stock

SKU: ELD
Ensim ELD liquid level indicators are designed for machine manufactures to control the level of oil or other liquid outside of their vessels / tanks. They can be mounted horizontal or vertical and do not require electrical power. download pdf datasheet
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Level Indicator NA/NA-V4A

In stock

SKU: NA/NA-V4A
The Kirchner tank level indicators NA and NA-V4A are suitable water, oil, alkalis or acids in aggressive environments. Each device contains a measuring tube made of borosilicate glass, stainless steel connection tube and a media specific float. download pdf datasheet
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Reflex type Glass Level Indicator ELH

In stock

SKU: ELH
Reflex glasses are used for observing level in pressure tanks and high temperature liquids. download pdf datasheet