Maintenance, Test & Measurement, Calibration


Automatic purge system for power stations

February 2023 Maintenance, Test & Measurement, Calibration

The Inspecta Automatic Purge System is a cost-effective, ambient air purge system that requires neither compressed air nor an additional power source to remove the fly ash buildup within the Inspecta pipe-sets for leak detection in power stations.

Instrotech designed the successful Acoustic Steam Leak Detection Systems (Inspecta ASLD) and has now developed a fully automatic purging system that is easily retrofitted to existing Inspecta installations. The installation of this system eliminates routine manual purging of the pipe-sets and maintains the leak detection system at peak performance, without manual intervention.

Installed in most Eskom power stations, Inspecta ASLD systems use acoustic detection technology that detects tube leaks less than 2 mm in diameter in the large boiler structure. The coal used by Eskom is very high in ash content, so there is a considerable amount of fly ash remaining after combustion. This fly ash swirls inside the boiler and quickly blocks the ‘listening’ pipe-sets that contain the sensitive leak detection microphones. Unless the systems are frequently manually or automatically cleaned their ability to detect the leaks early is significantly degraded.

Cost savings case study

The proven Inspecta ASLD has been shown to reliably detect steam tube leaks. To achieve this accuracy, the system must be correctly calibrated and the ‘listening’ pipe-sets kept clear of any obstruction that will reduce the sensitivity of the system. Experience has shown that if there is any obstruction that reduces the sensitivity by more than 10%, it will result in a measurable degradation of the Inspecta ASLD and a delay in the detection of a tube leak.

If the fly ash is allowed to build up over a period of five to six hours, this will result in a serious degradation in the leak detection sensitivity of the Inspecta ASLD. Under these degraded conditions, tube leaks may only be detected after progressing for some time. The resulting delay in detecting a tube leak may well result in extensive secondary tube damage and significantly extend the downtime to repair the damaged boiler.

Inspecta APS retrofitting

The Inspecta APS system can be installed into the current Inspecta ASLD configuration by simply replacing the existing Inspecta pipe-set with an Inspecta APS enabled one. All existing plant wiring remains the same. If there is a delay in the detection of a fast progressing tube leak by just a few hours, the downtime to repair the boiler may increase by more than five times compared to a leak that is detected earlier.

Installing Inspecta APS onto a boiler ensures the pipe-sets are automatically kept clear of fly ash, ensuring that the sensitivity of the Inspecta steam leak detection system is not compromised. This, in turn, will enable the system to reliably detect small tube leaks at a very early stage.

Benefits of the Inspecta APS

• Complements the existing Inspecta ASLD system.

• Easily retrofitted to Inspecta ASLD plant sensor network. The Binder connector fitted is compatible with the Inspecta HA-3 sensor. An option exists to fit power station-specific connectors if required.

• Significantly increases the effectiveness of the Inspecta ASLD system by automatically maintaining optimum performance levels.

• Improved early leak detection means that boiler outage times can be significantly reduced.

• Inspecta APS removes the routine maintenance human factor. It is automatic and does not require any human intervention to function.

• The system is purpose-designed to work in the extreme environmental conditions of a power station boiler house.

• AI-driven adaptive performance.

If early leak detection is achieved by installing Inspecta APS, and consequently reducing downtime for leak repairs in a large generation unit by only one day, the savings in electricity production loss exceed the cost of the system tenfold.


Credit(s)



Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

Infrared thermometers for electrical, industrial and HVAC applications
Comtest Maintenance, Test & Measurement, Calibration
: Comtest, distributor of Fluke test and measurement equipment, explains how handheld infrared thermometers are transforming maintenance in electrical, industrial and HVAC environments, with three measurement strategies and a wide range of practical applications.

Read more...
Reverse-engineering legacy industrial gearbox parts
Maintenance, Test & Measurement, Calibration
WEG Africa’s turbine workshop uses 3D scanning technology to reverse-engineer components for legacy gearboxes, turbines and compressors, enabling equipment to run for decades after OEM support and spare parts have dried up.

Read more...
Unlocking ICCP remote monitoring
Omniflex Remote Monitoring Specialists Maintenance, Test & Measurement, Calibration
Cathodic protection keeps buried and submerged pipelines safe from corrosion, but verifying it traditionally means costly, hazardous manual site visits. Omniflex explains how a retrofit module brings remote monitoring to ageing transformer rectifiers without replacing functional infrastructure.

Read more...
Microdieseling – the explosions you never hear
Maintenance, Test & Measurement, Calibration
Microdieseling is a pressure-induced thermal degradation mechanism in which entrained air bubbles are compressed so rapidly that the surrounding oil ignites, producing soot, varnish and sludge. WearCheck explains how it happens, why the damage varies, and how oil analysis detects it.

Read more...
Electrostatic spark discharge – when static strikes back
Wearcheck Maintenance, Test & Measurement, Calibration
WearCheck technical manager, Steven Lumley explains how static electricity accumulates in modern low-conductivity lubricants, why compact system designs and fine filtration make ESD more likely, and how to recognise the degradation it leaves behind.

Read more...
High-speed cameras for crash testing
Horne Technologies Maintenance, Test & Measurement, Calibration
Vision Research has expanded its Phantom C-series with two cameras optimised for crash and safety testing, offering 4 and 8 megapixel sensors rated to 170G, up to 1180 frames per second, and Phantom Academy application training planned for South Africa next year.

Read more...
SKF extends remanufacturing expertise to bearing clearance modification
SKF South Africa Maintenance, Test & Measurement, Calibration
Using its clearance modification expertise, SKF helped a mining equipment OEM salvage spherical roller bearing inventory that would otherwise have been scrapped, confirming a new capability within its remanufacturing services and avoiding redundant procurement.

Read more...
When maintenance-system compliance starts replacing plant reliability
Wearcheck Maintenance, Test & Measurement, Calibration
WearCheck ARC division manager, Annemie Willer argues that the greatest threat to effective maintenance is no longer a lack of technology, but the gradual replacement of technical judgement by CMMS compliance, leaving no one owning the machine.

Read more...
Automatic lubrication systems drive mobile mine machine reliability and uptime
SKF South Africa Maintenance, Test & Measurement, Calibration
SKF’s Lincoln P203 progressive lubrication systems are improving reliability and uptime on mobile machines at a Zambian gold mine, with installation of 45 units completing by October 2026.

Read more...
Nitration: the acid you didn’t see coming
Wearcheck Maintenance, Test & Measurement, Calibration
Nitration is as destructive as oxidation in many engines but far less understood. WearCheck technical manager, Steven Lumley explains how nitrogen oxide gases degrade lubricants, why the process is difficult to detect, and what oil analysis can reveal before damage occurs.

Read more...









While every effort has been made to ensure the accuracy of the information contained herein, the publisher and its agents cannot be held responsible for any errors contained, or any loss incurred as a result. Articles published do not necessarily reflect the views of the publishers. The editor reserves the right to alter or cut copy. Articles submitted are deemed to have been cleared for publication. Advertisements and company contact details are published as provided by the advertiser. Technews Publishing (Pty) Ltd cannot be held responsible for the accuracy or veracity of supplied material.




© Technews Publishing (Pty) Ltd | All Rights Reserved