The last time we talked about actuators in the field and what these can do with regards to predictive maintenance. I would like to stick with the topic maintenance for a bit. I recently read an article on the use of valves and actuators in the severe service sector. Now, as you can imagine, the severe service sector can be quite aggressive towards valves and actuators, which again can mean that a lot of maintenance has to be done on these products. Another thing might be that the valve is not easily accessible because it is located somewhere on the ground of the ocean. To put it simple, the valves have to be protected from and still fully function in an aggressive environment.
The article explains the method of thermal spray coating, with a focus on the high-velocity oxy-fuel (HVOF) process. Mrs Matyka, the author, explains that “these coatings can be protective, resisting wear, corrosion, oxidation and sulfi dation, or they can be functional, altering surface properties such as electrical conductivity, dielectric strength and thermal conductivity. Thermal spray coatings are generally thinner than weld overlays, and are not metallurgical bonded to substrates unless heat treated after deposition. As the price of nickel and other raw materials increases, they are a cost-effective alternative to fabricating entire components from expensive alloys.”
She then further explains the technology behind the coating process and goes into details when concerning valves. “HVOF coatings on the external surfaces of ball valves protect them from wear and corrosion, and used ball valves can be returned to their original condition eliminating the need to purchase new parts. HVOF coatings are also sprayed onto sealing surfaces and valve bodies to extend their service life.” The advantage is quite obvious: less maintenance, less cost, and fewer replacements of products.
However, coatings are obviously not the only options in this field. There are also other solutions to tackle valves and other technical equipment in a severe environment. At the Valve World Conference in Düsseldorf last year, we had a session on Materials where the quality of material selection was a key feature. During that session, Saudi Aramco talked about their experiences with Epoxy coated gate valves in seawater applications and another presentation was about the development of new low-lead brass material and its corrosion resistance.
Do you want to share some of your experiences with us as well? Then please feel free to send me an email at email@example.com. I look forward to hearing your stories.