Saddle for Horizontal Vessel Wear Plate Width:

[Outlaw500]

I am designing a horizontal vessel with 2 saddle supports.

Vessel desinged using compress software.

The issue I am having is that I have a customer that would like the wear plate width to be less than what my software will allow based upon the saddle width.

If I narrow up my saddle width the software will allow me to decrease my wear plate width and still do so with relatively low stress levels.

The issue is the customer wants a wide saddle with a narrow wear plate.

I'm assuming that there is an empirical relation ship to allow for flex in the wear plate and minimize the stress concentration from a "Stiff" edge of the wear plate in the shell.

Can anyone explain this in more detail?

Thanks.

 

[EngAddict]

The width changes the thickness that is used in the stress calculation. Refer to PD5500 Annex G or search Zick Analysis, you can probably find his paper for free.

 

[JStephen]

The original Zick analysis used a top flange (or concrete saddle) with an optional wear plate, which is required to be wider than the top flange. If you are not using a top flange, use one, and omit the wear plate.

Also note that making the wear plate thinner should allow it to be narrower.