ehtisham,l if there was such a thing, a bunch of us would be buying them [including me] As usual moltenmetal got it exactly right - an o'let is "integrally-reinforced 3000# welding fitting" and will turn any Sch10 pipe it is attached to into a banana.
The 'hot setup' is to use a set-on piece of pipe for your branch connection, per europipe. The rule-of-thumb is to drop down at least 2 sizes and go up at least one wall thickness. Thus on a 4NPS sch10 pipe header, the biggest branch you could set-on directly [no o'let used] would be 2NPS. And I would use 2NPS Sch40 [2 pipe schedules thicker]. With a full-penetration weld and a generous reinforcing fillet around this piece of 2NPS, it will have the same pressure rating as your 4NPS Sch10 header. This stub of thicker pipe only needs to be about 2 - 4 pipe diameters long, but 3 - 6 inches is 'more pleasing to the eye' on the 1/2, 3/4, and 1NPS branch connections.