Saddle without ribs?
Saddle without ribs?
(OP)
Hello,
I'm new in this site and at this kind of work. But I was asked to verify some calculations of a pressure vessel design.
The design is of a horizontal water boiler with 1500 l capacity (800mm radius) and 4,0 kg/cm2 pressure.
I'm researching the subject, my main sources are ASME Division 1, Zick's paper and Dennis Moss's book.
In this design the support of the vessel have no ribs, just the wearplate, web and baseplate (about 6mm thickness). In my research I never found any saddle without ribs, but I'm new at this.
So my question is, is this common? Or even allowed?
Thanks
I'm new in this site and at this kind of work. But I was asked to verify some calculations of a pressure vessel design.
The design is of a horizontal water boiler with 1500 l capacity (800mm radius) and 4,0 kg/cm2 pressure.
I'm researching the subject, my main sources are ASME Division 1, Zick's paper and Dennis Moss's book.
In this design the support of the vessel have no ribs, just the wearplate, web and baseplate (about 6mm thickness). In my research I never found any saddle without ribs, but I'm new at this.
So my question is, is this common? Or even allowed?
Thanks





RE: Saddle without ribs?
RE: Saddle without ribs?
Since only limited design data is available in the question, approx. check yields a thick of 2 to 3 mm, considering this thickness, if the overall weight of the equipment is very less and no other force acts, providing web plate only as a support option can be evaluated. However, as "marty007" said axial force required to buckle the saddle would be very less so this would force to consider high thick plates.
RE: Saddle without ribs?
1. Thickness of web
2. height of web
3. width of web
4. loading on saddle
5. temperature
6. material
7. is seismic loading to be considered
Slenderness of the web may require stiffeners. if the web is thick then it may not need stiffeners. With the information given no-one can give you a definitive answer.
RE: Saddle without ribs?
Frankly just the fact that you didn't found a saddle wihtout ribs something absurd was allready helpfull.
I guess I'll just recommend to include ribs in the design, it's not like it'll require a lot of added material or manpower to do it. Then, I'll do the calculations considering the ribs.
RE: Saddle without ribs?
RE: Saddle without ribs?
If diameter is 800 mm ribs/gusset may not be required. Also wear plate may not be required.
See PIP (Process Industry Practice) VEFV1104 Standard Details
Regards
r6155
RE: Saddle without ribs?
Short of the saddles being 3 meters tall, inside ribs would be excessive and a waste of parts and hours.
RE: Saddle without ribs?