I need a little advise on how to go about entering a 4" x 2-1/2" reducing butt welded elbow. Thanks for any help!

I've done it two different ways. The hard way and the easy way.

The hard way involves coding to the near weld point on the elbow, breaking the elbow into a number of different elements, with each successive element one pipe size smaller and thinner (or larger and thicker, depending which direction you code). Sometimes the geometry and coding can be tricky. If you choose to go this route, make sure you keep the same bend radius on all elements, as the bend radius for the fitting is the same for a normal 90° elbow of the larger diameter.

The easy way is to model it as a normal elbow and put the entire reduction at the far weld point.

I've only seen these used on older pump suction piping or at control stations where there is usually a base support welded to the fitting. If this is the case, I would take the easy route. I'm not sure you gain a whole heck of a lot from the hard method.

Any one else have other suggestions?