Three-way Displacement Indicator

The Three-way Displacement Indicator, also named 3D Expansion Indicator, is a professional measuring instrument specially used for thermal power boilers and high-temperature pipe systems. It visually detects and displays the three-dimensional thermal expansion displacement (horizontal, vertical and axial) of boiler headers, steam drums, main steam pipelines and other key components during heating, running and cooling processes.

It helps operators keep the thermal expansion within designed ranges, effectively avoiding pipe distortion, weld cracking, stress overload and equipment damage caused by blocked or abnormal displacement. It is a standard safety accessory for large boiler systems.

Main Structure

Fixed base & support bracket: High-strength carbon steel, firmly mounted on static boiler frame as reference point

Three sets of independent indicating assemblies: Respectively track displacement in three directions

Precision dial & pointer: Clear millimeter scale, high visibility, intuitive data reading

Flexible connecting rod & universal joint: Reduce friction, ensure accurate tracking even with multi-direction movement

High-temperature resistant parts: Adapt to long-term high-temperature working environment around boiler pipelines

Working Principle

Complete zero calibration under cold state before boiler operation.

When the boiler is heated up, pipelines and headers generate thermal expansion and move in three directions.

The connecting rod drives the pointers to move synchronously along with the displaced components.

Operators directly read displacement values from the dials. Once the data exceeds the allowable range, timely inspection and adjustment can be carried out.

Key Features & Advantages

Three-direction synchronous monitoring: Covers horizontal, vertical and axial displacement comprehensively

High measuring accuracy: Low-friction universal joint design ensures stable and precise indication

High temperature resistance: Suitable for harsh high-temperature environments of boiler rooms

Easy operation & maintenance: No power supply required, simple installation, long service life and few wearing parts

Clear reading: Standard scale design, convenient for on-site staff to observe and record data

Application

Widely applied in thermal power plant boilers, industrial high-pressure boilers, large heat supply pipe networks, petrochemical high-temperature pipeline systems, to monitor thermal expansion of headers, steam drums and large-diameter high-temperature pipes.