Difficulties associated with testing pipes in industrial plants have long been an issue for industrial businesses that want to keep operations running smoothly and extend the life of components. Now, thanks to research at the Faculty of Engineering, innovative wireless sensors are making this process faster, less labour intensive, more accurate and significantly more-cost efficient.

Major advances in wireless testing

Non-Destructive Testing (NDT) – the method used to verify the integrity of industrial components without rendering them unfit for further service – is used to measure the thickness and internal corrosion within a pipe wall and to help prevent pipes from failing unexpectedly. It is also a regulatory and insurance requirement that safeguards the safe operation of an industrial plant.  

Traditionally this kind of testing has been carried out by skilled operators who take measurements manually from designated points on structures. There are many problems associated with this method though, including: 

• The cost associated with measuring hundreds of thousands of points around a plant - this is often more than the budget of many operators and leads to them treating components conservatively and disposing of them with significant remaining life. 
• Significant variability in the location and thickness of points that need to be measured, leading to further uncertainty as to the true state of a structure when degradation is tracked 
• Inflated monitoring costs due to structures that are either difficult to access, or are clad with insulation which must be removed before taking measurements. 

To address these issues, Professors Croxford and Wilcox of Bristol’s Ultrasonics and NDT group have created wireless sensors for measuring pipe wall corrosion that can be installed permanently and are maintenance-free. 

Critically, the team at Bristol also designed the sensors to be inductively coupled to inspection hardware, enabling wireless measurements to be made without batteries on the pipe, fuselage or other components. The key development in this work involved engineering the inductive link so that the recorded measurements are of the same form as those recorded using a conventional wired link. This means that the measurements can be interpreted in the same way as those captured in industry under current best practice, reducing the complexity of certifying the measurements and increasing confidence in their use. 

Practical impact around the world

Following these breakthroughs, the research team at Bristol formed a spin-out company. Inductosense has deployed sensors that have significantly improved the accuracy and cost-effectiveness of NDT for global clients in a range of sectors including oil and gas, chemical, marine, nuclear and renewables.

Throughout these deployments, Inductosense products have delivered highly reproducible measurements at a defined and fixed position. One offshore inspection client commented that performance “far exceeded the expected tolerance levels of conventional manual ultrasonic thickness readings, and, in most cases, these variances were less than 1/100mm.”

The sensors are also RFID tagged, which enables the data to be logged and automatically uploaded for remote analysis. This measurement approach removes the need for NDT level 2 inspectors to take the measurements and reduces the associated costs.

As well as making the process more cost-effective, this approach also saves time. One of the largest pipe manufacturers in the world has stated that the “conventional approach takes 10-15 minutes per site to take a measurement”, whereas “Inductosense takes 10 seconds.”

In addition, the sensors can be attached underneath any layers of material such as insulation or cladding, which means they can be activated and read without removing the material first. The sensors can also be deployed in difficult-to-reach locations and activated with a data collector on an extendable probe, or in the future a robotic vehicle.

Where a pipe is clad, the Inductosense approach results in an even greater saving. This is particularly beneficial to the nuclear sector, where it can take up to three days to remove the cladding before taking measurements, resulting in a cost of up to £1 million per day of downtime.

Brings employment and investment to Bristol

The formation of Inductosense has also created investment and employment locally in Bristol. As of 2020 the company had grown to 16 employees, achieved total turnover over £1million, attracted £3.5million of private investment and £800,000 of grant funding and sold over 2,000 sensors to more than 30 clients globally.

Inductosense has also created a strong UK-based supply chain to manufacture its products, spending over £500,000 in the local economy with materials suppliers and electronics design houses such as Cubik2 and Spark Product Innovation. In the future, with sales expected to expand significantly, it is anticipated that this impact on the local economy is likely to grow even further.