Aboveground Storage Tank Bottom Plate Corrosion Detection and Monitoring

Detect Active Tank Floor Corrosion Without Opening the Tank

QAWRUMS provides periodic on-site acoustic emission testing solution and online long-term remote monitoring solutions for aboveground storage tank bottom plates.

AE sensors installed around the lower tank shell detect acoustic signals generated by active corrosion processes, corrosion-product movement, leakage and other active sources from the tank floor area. The system collects, locates and analyzes these signals to help evaluate tank floor condition, classify corrosion activity and prioritize further inspection or maintenance.

Acoustic Emission Testing for Vessels & Tanks Monitoring

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Quick Benefits

Non-intrusive tank floor condition screening
Often performed without opening or cleaning the tank
Detection of active corrosion and leakage-related sources
Periodic inspection and long-term online monitoring options
Remote data access and alarm notifications

Aboveground Storage Tank Bottom Plate Corrosion Detection and Monitoring

Looking for crack and leakage monitoring under pressure loading?
Pressure Vessel Monitoring

Overview
Solutions
Data Analysis
Cases & Resources

Why Monitor Storage Tank Bottom Plate Corrosion?

The bottom plate of an aboveground storage tank is difficult to inspect from outside. Internal inspection normally requires extensive preparation, which may include removing the stored medium, cleaning the tank and arranging personnel access.

Acoustic emission testing provides a method for screening active tank floor corrosion and leakage-related activity from sensors installed on the external tank shell.

When active corrosion causes corrosion products to crack, detach or move, elastic waves may be generated. Leakage and fluid movement can also produce acoustic signals. These signals propagate through the tank floor, stored medium and tank shell and are received by the sensor array.

The AE system processes the signals and provides information such as:

Acoustic activity level
Source distribution
Concentrated active areas
Signal intensity and energy
Corrosion activity classification
Condition trend over repeated tests

Suitable Tank Applications

The solution can be applied to:

Aboveground storage tanks
Atmospheric metal storage tanks
Low-pressure vertical metal tanks
Crude oil storage tanks
Petroleum product tanks

Chemical storage tanks
Water storage tanks
Large flat-bottom metal tanks
Newly manufactured tanks
In-service storage tanks

The final applicability should be evaluated according to tank material, pressure, medium, bottom structure, sediment level, operating condition and applicable testing procedure.

What Can AE Detect?

AE testing can help detect or evaluate:

Active tank floor corrosion
Corrosion-related acoustic activity
Leakage-related signals
Concentrated active source areas

Changes in corrosion activity over time
Abnormal tank floor acoustic events
Selected tank shell (wall panel) crack activity when suitable sensors and procedures are used

Acoustic emission testing of wall panels can detect acoustic emission sources generated by defects and cracks caused by stress increase during loading. Defect and crack locations include the wall panel base material, butt or lap welds of the wall panel, fillet welds connecting the wall panel to the pipes, reinforcing plates, and reinforcing (wind-resistant) rings, etc.

What AE Does Not Directly Measure

AE does not directly measure:

Remaining bottom plate thickness
Exact corrosion-pit depth
Defect dimensions
Remaining service life as a standalone result
Completely inactive corrosion

AE is best used as a screening and condition-assessment method. Areas or tanks identified as higher risk can then be prioritized for ultrasonic thickness measurement, magnetic flux leakage inspection, visual inspection or other verification methods.

Applicable Standards

Testing and evaluation procedures may be selected according to the project location, tank design and contractual requirements.

Relevant standards include:

JB/T 10764-2023, for acoustic emission testing and evaluation of atmospheric metal storage tanks
ISO 24489:2024, for acoustic emission detection of corrosion at atmospheric and low-pressure metallic storage tank floors
Other applicable national, industry or customer-specified procedures

Inspection & Monitoring Solutions

Choose the Right Tank AE Solution

QAWRUMS offers different system architectures for periodic inspection and continuous monitoring.

Periodic On-Site Inspection — SAEU3H

The SAEU3H multi-channel acoustic emission system is recommended for scheduled on-site tank floor corrosion inspection.

The system supports multi-channel acquisition, waveform recording, AE parameter analysis, external process inputs and source location. Different chassis and channel configurations can be selected according to tank diameter and sensor quantity.

View SAEU3H Page

Recommended for:

Periodic tank condition screening
Multiple tanks inspected by one portable system
Engineering inspection services
Projects requiring detailed waveform analysis
Time-difference or zone-location analysis
Tests performed by qualified on-site personnel

Centralized Online Monitoring — RAEM1-6

The RAEM1-6 multi-channel system collects signals from multiple external AE sensors and transmits data through network connections to local software, a private server or the cloud platform.

View RAEM1-6 Page

Recommended for:

Permanent monitoring of one or more tanks
Centralized sensor wiring
Continuous or scheduled automatic acquisition
Remote data review
Alarm notification
Long-term corrosion activity trends

Solution Selection Guide

Requirement	Recommended Solution
Periodic local inspection of different tanks	SAEU3H or RAEM1-6 with SWAE software
Hybrid of local inspection and remote long term monitoring	RAEM1-6 with SWAE software or QC Cloud
Wireless communication, cloud alarm and trend monitoring	RAEM1-6 with SWAE software or QC Cloud

AE Sensors

Different AE sensors can be selected according to tank material, monitoring defect types, installation positions, frequency range, sensitivity, surface temperature, installation environment and expected signal characteristics.

Sensor	Detection Defects
GI150	GI150 sensor is recommended for metal tank wall panels.
GI40	GI40 sensor is recommended for tank bottom corrosion monitoring.

The above sensors are integral sensors that include preamplifier inside. Contact us to help you select or evaluate the suitable sensors for your own project.

Preamplifiers and Cables

Preamplifiers amplify weak AE signals from sensors, while low-noise cables ensure reliable signal transmission in industrial environments. The preamplifier can be built-in the sensor (integral sensors like GI150 or GI40 above) or be external independent component after the general sensor.

View Preamplifiers

Data Analysis & Evaluation

Sensor Arrangement

AE sensors are normally arranged around the lower part of the tank shell to receive signals originating from the bottom plate area.

The final sensor number and spacing depend on:

Tank diameter
Tank material
Acoustic attenuation
Tank bottom structure
Stored medium

Sediment level
Nozzles, manholes and structural discontinuities
Required source-location method
Applicable standard or procedure

An on-site attenuation test is recommended before confirming the final sensor spacing.

Sensors should avoid structural discontinuities where practical. The installation height should also consider the internal sediment level and signal propagation conditions.

Data Collection

The AE system can collect:

Arrival time
Amplitude
Counts
Energy
Duration
Rise time
RMS (Root Mean Square)
ASL (Average Signal Level)
Frequency parameters
Original waveform
External process parameters

Data Definitions

Testing may be performed during a defined liquid-level condition, stabilization period or monitoring window according to the selected procedure.

Source Location and Activity Mapping

Two commonly used analysis approaches are:

Time-Difference Source Location

Arrival-timedifferences between sensors are used to estimate the position of acoustic sources on the tank floor.

Zone or Channel-Based Evaluation

The number and intensity of signals received by individual sensors or sensor zones are compared to identify areas with higher acoustic activity.

The output should be described as an AE source location or activity-distribution map, rather than a direct corrosion-depth map.

Corrosion Activity Evaluation

The analysis can consider:

Total hits and events
Event concentration
Signal amplitude and energy
Activity per hour
Repeated source locations

Channel comparison
Background noise
Tank operating condition
Historical trend

According to the selected evaluation procedure, tanks or active areas can be classified into condition levels and linked with inspection or maintenance recommendations.

SWAE Analysis Software

SWAE supports real-time acquisition, data playback and post-analysis.

Main functions include:

Source location maps
Parameter correlation graphs
Channel comparison
Data tables

Frequency-domain analysis
Filtering
Historical data replay
Waveform analysis

QC Cloud Platform

The cloud platform supports:

Remote parameter configuration
Real-time and historical data display
Waveform and parameter review
Automatic condition rating

Alarm notification
Email or SMS alerts
Data download

Case Studies & Resources

Case 1: CUPET Tank Bottom Inspection Training

A multi-channel acoustic emission system was used to inspect storage tanks in the Matanzas Port tank area in Cuba.

The sensor quantity and spacing were designed according to tank circumference and test conditions. AE results were used to support the planning of subsequent internal inspection and future periodic assessment.

Case 2: Special No. 1 Joint Station

Nine sensors were installed evenly around the lower external shell of a crude-oil storage tank while avoiding manholes, pipes and other structural discontinuities.

The system collected acoustic emission data during the defined monitoring period. Channel activity, energy distribution and time-difference source-location results were analyzed to identify concentrated source areas and evaluate the tank floor corrosion activity level.