ELBOW TRIMMING CALCULATION IN EXCEL
In Piping design, sometimes you may have to trim the standard elbow into nonstandard trimmed elbow. This will result additional work and cost to the project.
Normally Piping Designers will avoid and should avoid this situation. But if it is unavoidable or the designer thinks that to make the orthographic angle it may require more standard elbows, then he choose to to trim the elbow to the desired angle.
Trimming the Elbow means, trimming the 90 degree or 45 degree elbow to reduced angle elbow by cutting the elbow and grinding it and performing end preparation.
Note that you want to make 50 degree elbow, then you have only one option to trim the 90 degree standard elbow. Whereas your desired elbow angle is 30 degree, you will have two options. One is to cut the 90 degree elbow to 30 degree. Second option is to cut the 45 degree elbow in to 30 degree elbow. If the desired angle is less than 45 degree it is economical to cut the 45 degree elbow.
After trimming the elbow it is difficult to measure the angle for the pipe fitter, especially if it is very odd figure. So if the designer can provide the detail in the piping isometric then it will be very useful.
For designers it is difficult to do the manual calculations. So I made a small Excel sheet solution. You can download it from the below link.
I hope it will be useful and expecting your comments. You can share this page to your fellow piper by clicking the google+ (g+)
how about elbow trimmed with diameter over 24 "?
ReplyDeleteelbow radius x tan(required angle/2)
ReplyDelete