If self reinforced nozzles exist; why aren't all of them or at least for general design

[mynameis.sunjay]

If self reinforced nozzles exist;

Why then in General Engineering do all of them come in separately?
Why do you have to weld the flange, stem, reinforcing pad separately?
Why not have them integrated at least for general design specifications?

 

[SnTMan]

mynameis.sunjay "self reinforced" is kind of a broad term, usually would be taken to mean a nozzle neck of one sort or another joined to a shell element such as cylinder or head. It would generally exclude additional reinforcing elements such as a pad. So, a self-reinforced nozzle could be as simple as a piece of pipe set into / onto a shell element. It might include a separate flange, or not, a butt-weld nozzle.

"Why not have them integrated at least for general design specifications?" Are you familiar with a long-weld neck and so forth?

The exact assembly of pieces is usually a matter of reinforcement required, cost, availability, etc.

Regards,

Mike


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

 

[JStephen]

For general applications, it is an economic decision, and in many cases, it is cheaper to use a separate flange, pipe, and reinforcing plate than to use a forged fitting that incorporates all three.

 

[marty007]

For general applications, it is an economic decision, and in many cases, it is cheaper to use a separate flange, pipe, and reinforcing plate than to use a forged fitting that incorporates all three.

This becomes particularly true with high cost materials (Hastelloy/ Titanium / etc...).

 

[MikeG7]

Many fabricators don't like to put pads (the one's I know). They rather use a thicker nozzle. Increase in shell thickness is sometimes best option but depends on the added cost (it can be huge if vessel is large).
Many ways to address this and to find the balance of good design and good economy is challenging...

 

[SnTMan]

Fortunately, the practices for given classes of work tend to narrow the feasible options. Pick A or B

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

 

[meltedEng]

This becomes particularly true with high cost materials (Hastelloy/ Titanium / etc...).

Even if it fits the budget, the lead-times may not fit delivery requirements, and this can occur even with common 321, 316 etc.