Pressure vessel design

You should avoid a flange mounted end. (especially on high pressure vessels.)

I have seen a ± 1 m vessel with a lid to provide access for maintenance. The flange were designed to take a single row of high tensile bolts (1") spaced closely.

The stretching force on the bolts becomes to high due to the big area and pressure is lost.

For a better understanding on pressure vessels design, you should refer to ASME Section VIII, for 'Unfired Pressure Vessels. This gives information on, how to go about with the design of pressure vessels, depending upon its working pressure, volume to be stored, manhole cover aspects, and other things like whether it is of Verticle or Horizontal construction, flange design, connection bosses to be provided for draining of water, for fitting of gauges, valves, etc. How to test the vessel and at what hydrotest pressure for each working pressure and so and so.

The materials of construction is also discussed there in, with its welding requirements.

Hope you will be able to get the answer to your problem there.

You must be joking. These bolts and/or flanges clearly were not sized correctly. I have designed and used many high pressure vessels (up to 150,000 PSI) that incorporate flanged ends and pre-stressed tie rods with success. These pressure vessels have been in production in the Hot Isostatic Pressing industry for over 15 years with no issues. By the way, the spelling of "to" in the case of "to high" is "too". I'm not trying to be a jerk but may have succeeded. I simply dislike misinformation and misspelled words. Ah well....

1. I visited a friend during the day who installed a system including a pressure vessel. The vessel did not perform to specs. It was soon evident that the bolts on the under designed flange were stretching. The rest of the day was wasted in an attempt to contact the supplier and to get my friend going. The night when I visited CR4 the first post I saw was the question about the design of pressure vessels. My frustrated reaction was to tell him rather not to start. I eventually deleted most of the post. I must admit that I am not in pressure vessel design, the highest pressure used so far was for domestic supply.

4 Sorry about the TOO. It is a mistake I always make.

5 Are we obliged to use American spelling?

Design of pressure vessel includes the following:

a. Process Design to include the function of vessel itself, i.e. in which the vessel will be used for, e.g. as a distillation tower, separator, reactor, filter, accumulator, ... etc. including vessel sizing, operating pressure, operating temp., fluid, ......etc.

b. Mechanical Design to include: vessel material and its allowable tensile strength, design pressure, design temperature, methods of manufacturing & welding, methods of tests & examination, PWHT,....etc. which can be in accordance with ASME code, Section VIII.

Mechanical design includes detailed engineering, design drawings, stress analysis and design calculations.

Now, what do you want to learn about? Process design or Mechanical design?

You are 100% correct about the necessary steps in order to answer the question posed here, but looking at the posts to most of the questions that appear in these forums I now can see why many of the people we work with everyday in industry are annoyed by the fact that we always tend to answer a question with a more complicated question. So my question to the original author of this topic is simply what is the pressure vessel you are trying to design going to be used for?

"I want to learn how to design a Pressure Vessel,.........."

First the term Pressure Vessel covers an extremely wide range of applications. From small portable compressed air tanks, to boiler drums, to large outdoor storage tank of various liquids, either pressurized or not, etc.

Second Pressure Vessels require consideration of various disciplines of engineering. e.g. Strength of Materials, Metallurgy, among others.

A working knowledge of mathematics is an essential prerequisite as are several other disciplines.

There is no short cut way to do the job right. Many ways to do it wrong.

A good reference is PRESSURE VESSEL HANDBOOK, by Eugene F. Megyesy, published by Pressure Vessel Publishing, Inc. P.O. Box 35365 Tulsa, Oklahoma 74153 USA.

There is also computer software that will guide you through the design process. It is called Compress provided by Codeware Inc., 3100 S. Gessner Rd., Suite 610 Houston, TX 77063. The codeware web site is:

http://www.codeware.com/

Well put, hydman.

When you detail your application make sure to cover the following. Is this vessel for internal or external pressure? What liquid/gas is inside and outside at what pressures? What kind of access is needed to the vessel?

Depending on those issues, design advice can vary greatly.

<Where to Start>?

Please answer these to yourself first:

• Must you have a pressure vessel. To cook? As a Catalytic Reactor? Fractionator Column?
• Can you reduce the Height/Dia./ Volume/pressure/Temperature-to minima ??
• Can you have only the "wetted" surface thin Al/ SS(type?) rest Carbon Steel?
• Can you minimize manholes/Inspection holes/handholes/piping/feeder/purge ?
• Can you minimize Instrumentation holes.Where are critical points for sensing
• Must it be Cylindrical/Spherical. Can shape be Plain Cylinder/stepped/dumbbell

Once you answered--you are on your way.

Rest are in various CODES.

And in basic textbooks on Strength of Materials.

Finally in CR4.

Now START Designing. Plenty of hard work ahead!

Mind you--- at the end of your loving toil:

The fabricator might say "This kind of welding is unreliable---may cause an accident"

Or the Erector might challenge "Show me how to Erect it"

Or your CEO might say-"I cannot justify such a heavy expense"

Or your Materials Manager throws up his hands and challenges you to get that material in that thickness from anywhere at all.

It's nice see how many people know about every theme and how they reacts and at the end I laught for myself in satisfaction because sometimes it seems like a joke only for get together those people in a moment of relax.

Thanks for all of you.

(And grammar too)

Thanks to you for lettings us know that some of these "JOKE' inquiries are just that.

We will likely treat all similar and even a few serious requests for information as "JOKES"

because of you and your ilk!

How cowardly to hide you identity as being a 'Guest.'

Thanks to all my big brothers, for all the suggestions............... and ...........please dont fight, we r not here to pull legs but to help others

There are British_Standards for fired- and unfired-pressure-vessel design.

However, other threads are valuable: is a pressure vessel needed? Can the process design be altered to eliminate the need for a pressure vessel? This line of thinking is called 'process intensification'. What one doesn't have, can't go BANG!