Angle and globe valve flashing solutions stand to significantly increase control valve service life and alleviate costly erosion issues, says an industry expert.
Text and images by IMI Critical Engineering
Flashing caused by pressurised steam is a destructive phenomenon that occurs in many industries. When controlling steam flow, flashing can take place, and when this happens it can result in severe erosion and damage to the valve components.
By reducing flow capacity and eroding the valve itself, flashing is causing unplanned maintenance, reduced reliability, and unacceptable critical safety risks, says Mike Semens-Flanagan, Global Engineering Director at IMI Critical Engineering. With the issue continuing to put pressure on bottom lines in the gas processing sector, Mr Semens-Flanagan is calling for the adoption of new technologies to help resolve these timely and costly issues.
“For years, plant operators in industries where pressurised steam is used, have struggled with reduced operational performance and diminished valve lifespan as a result of flashing erosion,” explains Mr Semens-Flanagan. “The spiralling maintenance and repair costs that ensue can partially be attributed to the wide-scale adoption of control valves ill-suited to withstand the extreme velocity and pressures over the valve structure.”
“To mitigate the safety risks of valve erosion and reduced asset performance, the sector must be open to new and accessible innovations,” he continues. In line with this approach, IMI Critical Engineering has developed EroSolve Flashing solutions to cope with severe flow conditions based on IMI proven technology.”
EroSolve Flashing
The component’s angle configuration is designed with hardened trim material, an enhanced seat, and a multi-path, multi-turn plug design to move flashing points away from critical trim parts and, therefore, withstand the most severe conditions. Its globe configuration option, on the other hand, utilises a seat basket to reduce downstream velocity and avoid damage to the valve body, without having to modify the existing pipe configuration.
The effectiveness of EroSolve Flashing has already been demonstrated, for example in a combined cycle power plant that experienced erosion issues in the Heat Recovery Steam Generators (HRSG). Engineering analysis defined the root cause to be high-velocity vapour and low-velocity flow fluids, creating a high degree of flashing conditions. With EroSolve Flashing installed in May 2021, the replacement component experienced no damage when inspected after a year of operating.
“Resolving safety concerns while maximising asset production efficiency, is a key priority across the gas processing sector,” Mr Semens-Flanagan concludes.
“This is especially the case for valves in applications facing extreme velocity, pressures, and severe flashing. EroSolve Flashing has been configured to effectively overcome these difficulties and create significant savings in terms of lifecycle costs and valve maintenance.
“When accompanied by the maintenance and servicing experience of expert personnel, such as our own Valve Doctors®, valve lifecycles can be extended by up to four times compared to similar products. At a time where all sectors and specifiers are under pressure to reduce capital expenditure and operating costs, selecting these solutions allow organisations to do more with less.”
Flashing
Flashing occurs when the pressure of a fluid passing through a valve is lower than the same substance’s vapour pressure. This causes the fluid to boil – otherwise known as ‘flashing’. Flashing can both ‘choke’ the valve, reducing flow capacity through it, and can damage the valve itself through severe erosion.
If left unchecked, flashing will reduce the operational performance and lifespan of the valve which is why IMI Critical Engineering has created a new solution, EroSolve Flashing, to cope with flashing conditions. This solution can replace the whole valve or just the trim as needed. EroSolve Flashing solutions will reduce valve erosion and operational costs, resulting in better performance, less maintenance, and a longer valve lifespan.
