Can anyone tell me in which cases we use double sided dove tail and in each cases we use one sided dove tail?
In both cases the o-ring is confined/held tightly in the groove...
I didn't know there was such a thing as single sided dovetail. The two web hits I found did not recommend dovetail because of the reduction of "void" area. I'm guessing that is the empty space that gives room for the oring to expand. If that's the case then the double dovetail would be worse. The following gives some dimensions for both:
It wouldn't make any difference complexity wise whether you were cutting a single or double dovetail groove. In fact, it would be easier to cut a double dovetail groove since a single would require a tool change while you might actually be able to get away with a single tool in the double dovetail groove if the tool was able to make a plunge cut to start the cutting path. Granted, a single dovetail groove can be cut using a dovetail bit with a slightly larger shank diameter, but it would still require a tool change.