Selection of branch fitting 1

[NovaStark]

According to ASME B31.3, a fitting can be chosen from other standards such as MSS SP-97.

However these don't go into detail about the actual selection process.

For example, when would one just opt for weldolet instead of a sweepolet connection ? If it is simply up to the designer, what factors would influence this ?

 

[NovaStark]

One last question in terms of naming, as olets are bonney forge fittings and looking up MSS SP 97 for IRBWF shows a weldolet looking item does that mean that IRBWF would reference a weldolet ? And if I wanted to specify something like a sweepolet, would I name it generically as a welded-in contour insert ?

 

[XL83NL]

Any name ending on -let is, I think, considered a tradename. IRBWF is the general name, used by (amongst others) Codes, like B31.3.
But people just know them by that name; weldolet. Although a sweepolet is not that known, a welded-in conttour insert would be even more unknown I presume.

 

[Ehzin]

What's the temperature and material of where you encountered these if it happened to be specific to just one system? I'm a little light on the details but I'm aware of at least one scenario where signs of creep were found at the weld between a weldolet and run pipe and a sweepolet/vessolet was being considered to reduce the SIF of the joint to mitigate reoccurrence.

Thanks,
Ehzin

 

[NovaStark]

@XL83NL

Yeah that is what it sounded like

@Ehzin
This was a 304h SS at around 1175F however my failure was on the parent metal and not the weld.