Valve Durability
Enhancing valve durability in residue upgrading : tackling fouling , sulphidation and coking
Residue hydrocracking technologies are evolving , but persistent challenges like fouling and sulphidation continue to impact valve performance .
Through field insights and experimental research , Velan has developed coatings that considerably reduce fouling and extend the life of valves in these harsh environments . This innovation aims to improve corrosion , coking performance and reliability in residue upgrading , offering a new solution for the industry .
By Fadila Khelfaoui and Luc Vernhes , Velan Inc .
Residue hydrocracking technology has been evolving since the early 20th century to maximise the conversion of heavy crude residues into valuable products . Over the decades , advancements have led to the development of more efficient processes with higher conversion rates and improved economic feasibility . Since the 1980s , Velan has played a key role in this evolution , supplying ball valves for the delayed coker market , one of the most widely used processes for breaking down heavy oil at low pressure and high temperature . The delayed coker process , first introduced in 1929 , remains a dominant residue conversion method , with over 200 operating units worldwide . This thermal cracking process achieves conversion rates of up to 80 %, transforming heavy residues into lighter hydrocarbons . Additionally , it has evolved to produce valuable by-products such as needle coke , essential for battery and electrode manufacturing . However , as refiners sought even higher yields and reduced coke formation , new hydrocracking technologies emerged to improve conversion rates . The 1960s saw the development of ebullated bed hydrocracking , which introduced a more advanced approach to residue processing . Unlike delayed coking , this process utilises a catalyst in a fluidised bed , improving hydrogenation and reducing coke formation . Technologies such as H-Oil ® ( Axens ) and LC-FINING / LC-MAX ( CLG ) became industry standards . This process significantly boosted conversion rates to 70-90 %,
Figure 1 : Example of fouling in a ball valve used in residue upgrading operations .
with around 30 operating units globally . Despite these advantages , ebullated bed hydrocracking required higher capital investment and operational complexity , leading to the search for even more advanced solutions . By the 1980s , slurry-phase hydrocracking emerged as one of the most advanced residue upgrading technology . This process delivers conversion rates of 90-99 %, virtually eliminating coke while maximising liquid yields . However , due to its higher operational complexity , it has been adopted in only around 10 units worldwide .
Figure 2 : Forensic failure analysis of ex-service ASTM A638 ( Grade 660 ) alloy seal ring .
38 Valve World March 2025 www . valve-world . net