There is a company in Houston called WFI. They make a piece called a "vesselet" that looks like a flange, weldolet, and nipple but its all one piece. They forge it and machine it, so there is no welding. They probably have a website. I have never used one, but I recall that they...
In what I have seen, category D ends up being plant air, instrument air, cooling water (although the chemicals in it might make it not Cat. D) and potable water. Not much. Pretty much ends up stuff you could swim in and be o.k.
Certainly, I have NEVER seen steam listed as Cat. D.
Would you...
Yes, that's right. Normally, the loadings that cause problems for the vessel nozzle is bending (longitudinal and circumfrential, but sometimes combined bending... just a sqr rt sum of squares of long and circ.) and then radial load. Radial load is the load tending to punch the nozzle into the...
Pretty much the longitudinal shear, circumfrential shear, and torsion are loads which have a small impact on the answer. We generally find that they can be left out.
Richard Thompson, P.E.
Pipe Stress Engineer
Houston TX
S&B Engineers and Constructors, Ltd.
