Valve World Magazine February 2025 | Page 21

3D-PRINTED VALVES

Disk stacks constitute part of a recommended spares programme , allowing a site to operate with minimal downtime . These stacks need replacing more often when fluid velocity control is not maintained , or when a site has an older , poorly designed control valve installed . These valves also wear naturally over time , making it essential to have an adequate maintenance programme in place . IMI regularly works with customers across the globe to replace faulty valves . As with any effort on this scale , this work has a significant impact on the environment and needs to be measured accurately to ensure that IMI is making legitimate progress on its own climate commitments , as well as those of its customers .

What did the life cycle assessment cover ?

Ricardo ’ s life cycle assessment examined the replacement of a faulty disk stack in a valve manufactured by IMI . The study assessed a large valve ( eight inches ) and a small valve ( three inches ) across three different replacement scenarios : 1 . Replacement of disk stack only via traditional manufacturing methods 2 . Replacement of the full valve via traditional manufacturing methods 3 . Replacement of the disk stack only via additive manufacturing

Full valve replacement included replacing the disk stack , body and bonnet , while the other two replacement scenarios only involved changes to the disk stack . The life cycle assessment was a cradle-tograve study . However , the valve ’ s use-phase was excluded because data was not available to support claims that different replacement scenarios have different use efficiency savings . As such , the study only examined the sourcing and production of raw materials required for each replacement scenario , manufacturing inputs , the transport of parts between sites and the end-of-life fate of finished parts , including transportation to a disposal location .

Setting the metrics

There are several ways to measure the environmental impact of a product or industrial process . Climate Change Impact ( also known as Global Warming Potential ) is arguably the most significant . Carbon Dioxide Equivalent ( abbreviated as CO2-eq ) is a metric measure used to compare the emissions from various greenhouse gases on the basis of their CCP / GWP . 3 CO2-eq is the principal metric given in Ricardo ’ s final report . Disk stacks , which can be either traditionally

No . Replacement scenario Replacement part ( s )

or additively manufactured , require different levels of maintenance and yield different lifetimes . This means that under a specific replacement scenario , a valve can last a certain time before it needs to be replaced or upgraded . IMI had to make some assumptions based on existing knowledge in this field , which were supplied to Ricardo . The table above provides a breakdown of the three replacement scenarios covered in this study . As the table shows ( Figure 1 ), a traditionally manufactured replacement disk stack is assumed to last one year . Any facility using this replacement scenario would therefore need 10 new disk stacks over the set study horizon of 10 years . The full valve replacement is only required once , while disk stacks manufactured additively would need replacing twice over the 10-year period . Ricardo factored in these differences when analysing the replacement scenarios as part of a sensitivity study , provided in the appendix of its report .

The additive advantage

Ricardo ’ s life cycle assessment found that the additive disk stack replacement manufactured by Retrofit3D – IMI ’ s additive manufacturing valve trim solution – was the preferable scenario across all the environmental indicators analysed . This finding was the same for both the large and small valve categories used in the study . In other words , additively manufactured disk stacks should be considered environmentally advantageous when compared with the other valve replacement methods . This is due to the different materials used and the lower quantities needed to produce them . The small valve with an additive disk stack replacement had a Climate Change Impact of 146kg of CO2-eq , while the large valve with an additive disk stack replacement recorded 1,360kg CO2-eq . Both of these figures were calculated based on the 10-year study horizon .

For the large valve , this represented :

• A 96 % Climate Change Impact saving when compared with replacement of the full valve via traditional manufacturing .

Lifetime ( in years )

Number of replacements per lifetime

Figure 1 – IMI set the project ’ s horizon at 10 years . This table shows the number of replacements required over that period for each replacement scenario .

• A 94 % Climate Change Impact saving when compared with replacement of the disk stack only via traditional manufacturing .

For the small valve , this represented :

• An 87 % Climate Change Impact saving when compared with replacement of the full valve via traditional manufacturing .

• An 85 % Climate Change Impact saving when compared with replacement of the disk stack only via traditional manufacturing .

Findings and conclusions

Unsurprisingly , for the large valve , the least favourable scenario in terms of Climate Change Impact was replacement of the full valve at 34,000kg CO2-eq . This was due to the body component , which required more material and resources ahead of delivery to a customer site . For the small valve results , however , the traditional disk stack replacement was the least favourable option , as it contributed 1,130 CO2-eq . This is noticeably more than the 988kg CO2-eq for the full valve replacement , which was due to the raw materials required for replacing 10 traditional disk stacks over the 10-year period . Extra work was carried out to determine the sensitivity of these results against assumptions made about the mode of transport , valve lifetimes and the frequency of replacement . Even with these factors , the additive replacement scenario still proved favourable . Consideration was also given to assumptions about the frequency of replacements . Even with a ‘ tipping point ’ factored into the results , the additive disk stack still outperformed the other two scenarios . It was determined that an additive disk stack would need to be replaced every two or three months to be less favourable than the traditional replacement options . For more information on Retrofit3D , visit : https :// www . imi-critical . com / trim-upgrades / retrofit3d-trim-upgrade /?& utm _ source = trade _ website & utm _ medium = pr

3 https :// ec . europa . eu / eurostat / statistics-explained / index . php ? title = Glossary : Carbon _ dioxide _ equivalent

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