MAWP limited by nozzle parts

[Ehiman1]

Hello everyone,
I am designing a heat exchanger and I noticed that Mawp is limited by nozzle flange on shell side and a vent from tube side.
In accordance with API 660 nozzle reinforcement (reinforcing pad) Can not limit Mawp but in this case the mawp is limited by a flange and a opening. Do you think it is accettable?
In the client’specifications I didn’t find anything about this point.

 

[MJCronin]

What was stated by your purchase specification ?

Generally speaking, The maximum allowable pressure should be limited by the shell or heads, not by minor parts such as flanges, nozzle necks, reinforcing pads, piping, fittings, or manways. Your design report should clearly identify the limiting component.

You may be interested in some of these older discussions:

https://www.eng-tips.com/viewthread.cfm?qid=255894

https://www.eng-tips.com/viewthread.cfm?qid=207527

MJCronin
Sr. Process Engineer

 

[SnTMan]

Ehiman1, nozzle reinforcement is a more general term than just referring to a pad. If your vent opening limits MAWP it does not meet API 660.

If the nozzle flange rating is specified by the client it is permitted to limit MAWP, in the absence of other contract requirements.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[Christine74]

API 660 only requires that the MAWP of a heat exchanger not to be limited by nozzle reinforcement or by the bolting in the girth flanges. Nozzle reinforcement is not listed as a criteria.

My opinion only, but whenever possible I think the flange ratings on the heat exchanger nozzles should match the flange ratings of the attached piping.


-Christine

 

[GD2]

Ehiman1,
Let's start from the basic.
You are designing a HX based on Client design specification/Datasheet. Correct?
Your design code I would assume is ASME SEC VIII Div1. Correct? You are also using API 660 for design features. Correct?
The basic fundamental in a pressure vessel design is that one or more components will be limiting in terms of MAWP.
You are saying that the shell side is limited by the flange and vent on the tube side.

As long as both meets or exceeds the given design pressure at design temperature, it will meet the code requirement.



GDD
Canada