nozzle reinforcement pad

[stonetech]

Hello, everybody here,

When do we need a nozzle repad on a vessel? How to calculate the repad size? Any comments are appreciated.

Thanks in advance.

 

[CodeRef]

See Appendix L of ASME VIII-1 for examples. (assuming it is a Section VIII-1 vessel)

There are three kinds of people in this world; those who can count and those who can't.

 

[TomBarsh]

You would need a reinforcing pad when the reinforcing area available is less than the reinforcing area required per your design code or rules.

As an alternate, you could increase the thickness of the shell or nozzle neck in lieu of a separate reinforcing pad. Ways to do this would include an "insert plate" in the shell. Or use a forging for the nozzle, one that has a "heavy barrel" where it attaches to the shell.

If you are left using reinforcing pads: don't make it too big (it'll be uneconomical and won't be as flexible as the shell), don't make it too small (it'll be hard to handle and weld, and hard to get test fitting in), don't use it too hot (in creep range temperatures, you'll create a hard spot on the shell), don't make it too wide (it'll flex up under nozzle loads and won't be as strong to resist those loads), etc, etc,

 

[TomBarsh]

Speaking of nozzle loads, you could use reinforcing plates if the calculated stresses in the shell due to these loads are excessive. This might be the case even if there is sufficient reinforcing area for the opening.

 

[stanier]

Suggest you get a copy of Nozzlepro software. The cost is minor compared to the design expense. Just Google it.

Geoffrey D Stone FIMechE C.Eng;FIEAust CP Eng

http://www.waterhammer.bigblog.com.au

 

[LSThill]

stonetech (Mechanical) and stanier (Mechanical)


Other option FE/Pipe 4.5 by Paulin Research Group:
Model Type SAM General Area Replacement Code Area Replacement ASME Section VIII Division 2 Article D-5 and Article D-6.

L S THILL