question about olets

macdaddy20'
I have to wonder why you (with 32 years of experience) are asking this question. You should already know the answer to this.

What does the Piping Material Line Class Material Specification say? There should be a Branch Table for this.

The Piping Material Engineer would have considered the Commodity, Operating Pressure and Operating Temperature to make the Branch tables.

Low Pressure, Low Temperature Services (Cooling Water) would normally have;
- Size-to-size branches = TEE
- Size to one size smaller branch = Reducing TEE
- Size to one or more sizes smaller branch = Stub-In

Higher pressures, higher temperature Services requiring Branch Reinforcement (Hydrocarbon Liquids or Vapors) would normally have:
- Size-to-size branches = TEE
- Size to one size smaller branch = Reducing TEE
- Size to one or more sizes smaller branch = Weld-O Let

What is your position/job relative to this situation (Piping Designer? Piping Material Engineer? Client?)
What are you not telling us about this situation? Is this all new piping or is this a new branch off an existing line?

If you need an 8" x 6" branch, that's a fairly conventional run/branch size combination.
Can be found on Bonny Forge - www.bonneyforge.com/resources/BC.pdf

(I couldn't comment on whether this is in your branch connection chart though).

I have worked with specs that call out all reducing branches with olets / stub-ins.

There is no reason why, on a low pressure / low temp line, you couldn't use an 8"x6" stub-in.