There are a number of changes that take place in API 20E 2012. One that shakes things down to the core of the American Petroleum Industry is the fact that oversized nuts will not be allowed.
Why is this such a big deal? Well we have been oversizing nuts to allow for coating thicknesses for a very, very, very long time. The standard cut allows for about 4 mils. of slop between the ID threads of the nut and the OD threads of the bolt, (fasteners). In order to allow for coatings to help protect the longevity of the fastener both anodic and torque reducer. (Corrosion and Erosion.) We had to allow .005 over sized for PTFEs and galvanizing, we had to allow .010 over sizing of the nuts for ceramics and more heavy duty coatings. What the API 20E , is says is that this is no good. That there is not enough thread on thread action in order to keep the system's torque and not enough strength in the threads layering. What has happened so far, since 2012? Not much. If you are going to have a law, you are going to have to enforce it. Which is hard to do when there are very few sources outside of coatings to get our answers. Solutions: A complete alloy system that allows lubricity, torque retention, corrosion qualities of better than 5,000 salt spray hours (ASTM B-117), strength of carbon steal, no tendencies for hydrogen embrittlement and less than stainless steel. I know, I sound like I have a solution. Well, I do. |
Author; Ian MacMoyPolitical Writer, Corrosion Engineering, Cook, Poetry, Triathlete ArchivesCategories |