Vuoplan Oy has been active already for more than a decade in challenging material selection and failure cases in oil- and gas; pulp- and paper and heavy machinery industries. The basic principle for successful material selection is to think also the unconventional possibilities - and make the decisions based on calculated facts with criteria agreed together with the customer.
Vuoplan Oy has a solid track record with working in a very broad materials range, e.g with the following material groups
- Steel, Stainless steel and duplex steels
- Special alloys of Ni,Ti,Al and others
- Technical plastics and carbon based materials
- Composite materials (plastic, steel and ceramic composites )
- Hard coatings (electrochemical, spray coatings, HVOF etc.)
- Sof coatings (Rubber-, plastic- and elastomer based)
Case 1, upgrade to duplex-steel
Customer made a notice, that a pipeline made of stainless steel (1.4404 / AISI 316) after valve outlet had been severely thinned after only one year of service. Investigation indicated the main reason for damage to be erosion-corrosion, caused by the flow media and the process conditions. Vuoplan Oy made recommendation to upgrade the pipeline to duplex steel 1.4462 / UNS S31803, together with the valve which after inpection was found to be worn as well. The renewed pipeline was inspected after a year of service with no indications, even though the process conditions remained the same.
Case 2, Elastomer incompatibility
The elastomeric flange gaskets used in a pipeline had been severely hardened near the drains, effectively causing leaking in normal process conditions. Thorough investigation revealed only one remarkable detail - during process turnaround, the pipelines had been cleaned with steam purging; everything else was according to operating instructions. At the same time, it was found that the gaskets were of FKM rubber (trademark "Viton") - which is known to be largely incompatible with steam. The solution was to change the gaskets to EPDM rubber, which luckily could be used with process flow media, and which has excellent resistance to steam as well.
Case 3, external leak from valve body
A valve in a process was noted to have an external leak from the valve body. After a careful failure investigation, it was concluded that the reason for leakage were the internal casting defects, which could not be seen outside the cast surfaces. These defects could have been noticed effectively only via non-destructive volumetric inspection, such as radiographic inspection. This particular case led to develop a quality instruction and practice for the customer, which included more detailed technical requirements for valve purchasing to exclude such issues and more thorough incoming goods inspection upon the arrival of the future deliveries.