Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here


Thick Walled Pressure Vessel for Pressure Testing

Thick Walled Pressure Vessel for Pressure Testing

Thick Walled Pressure Vessel for Pressure Testing

This is my first vessel I have designed and probably my last. We are wanting to build a vessel for pressure testing (with water) downhole tools. The ID of the vessel would be 6 inches and 8 feet long. The maximum pressure we would need to test at would be 20,000 psi at room temperature. This vessel will be small enough that it does not fall within ASME Section VIII Div.1's scope, but that is the code I am designing to (anyone have a more appropriate code?). So far, I am just considering the shell and haven't started considering the fittings that will need to be installed. I calculate a required wall thickness of 2.2 inches based on a max. allowable stress of 40,000 psi. This max. allowable is loosely based off of SA 693 (17-4 PH) material. Now I realize that this won't actually work forming a plate this thick into this tight of a radius, for a couple reasons.
So, my question is really, what do people make such a vessel from? Am I going to have to have this cast or forged?

RE: Thick Walled Pressure Vessel for Pressure Testing

I would say that is a bad vessel to learn on. You'd be better off getting someone to design and fab that routinely does this.
There is an ASME Section VIII Div. 3 that would fit the application.
"2019 ASME Boiler and Pressure Vessel Code (BPVC), Section VIII, Division 3: Alternative Rules for Construction of High Pressure Vessels"
I would expect it to be made from some form of pipe. I would specify the volume required, and let the designer select ID and length for best economy.

RE: Thick Walled Pressure Vessel for Pressure Testing

Agreed, design conditions make it poorly suited for Div. 1 and for learning on. Contract it out.



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

RE: Thick Walled Pressure Vessel for Pressure Testing

I appreciate the advice. Contracting it out is kind of what I was thinking as well, but I wanted to at least get an idea for myself what was required. I'll look through Div. III.
Using a pipe would be great, but I don't know of any off the shelf pipes that would come close to these dimensions.

RE: Thick Walled Pressure Vessel for Pressure Testing

It won't be an off-the-shelf pipe - it will be custom-forged. And certainly get some help with this. At 20ksi internal pressure, water is ever-so-slightly expansible/compressible. A failure in this has a high likelihood of killing someone or doing serious damage to equipment.

RE: Thick Walled Pressure Vessel for Pressure Testing

IF you really want that strength level then you should use 15-5PH, it is designed for thicker sections.
This would be a custom forged piece of pipe, but likely made to a pipe spec.
Or they would take a 12" piece of bar and gun drill it out.
Hire someone to do this, design and fabrication.
Your full breach opening will be very difficult to get right.
This is closer to a hydrostatic press than a pressure vessel.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy

RE: Thick Walled Pressure Vessel for Pressure Testing

You could consider designing to API 6A. The code has dimensions and material requirements for bore and OD for 138 MPa (20000 ksi) parts.

RE: Thick Walled Pressure Vessel for Pressure Testing

It sounds like you need API CASING, 5CT. That is what is going to be used with your down hole tools. Grade Q 125 with "good" NDE ( I do not have a current 5CT so can't give a supplemental requirement). End caps will be interesting as normally the casing is threaded to couplings. There are a variety of threads available ; working with a supplier would likely be the best way to find end caps and threads. Likely a vendor of down hole accessories and pup joints may have something on hand. There will be no welding on the tubulars. Depending on availability other grades could be used T-95, C110, etc. Also check with wellhead manufactures , 20 ksi and 25 ksi equipment is not common but it is made ( and pressure tested). Start with Cameron , Grey, FMC - I expect these names have changed because of various business changes since I retired. Actually with the 125 ksi yield material , the wall thickness would be about 1.25" with a 2:1 safety factor . So very likely some facility has this small length in inventory.

RE: Thick Walled Pressure Vessel for Pressure Testing

It sounds like your vessel would be a one-off, which means you'll want to find stocked materials. The few times I've ventured into the very high pressure world, it's always been for one-offs and this company has come in handy: http://specialtypipe.com/steel-pipe-and-tube-inven...

They stock SA-106 GrB/C pipe in much thicker walls. A quick look found one 12"OD x 6"ID for example.


Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


White Paper - Understanding Critical Specifications for Dynamic Metrology Applications
Different types of metrology have different critical specifications to consider when determining which actuator technology to use. This white paper goes into detail on the demands of dynamic metrology applications as they apply to the selection of precision linear motion control components and systems. In addition, the relevance of Moore's Law is examined in the context of the industry. Download Now
White Paper - Permanent Non-Welded and Cold Bent Piping Solutions
Commonly used welded piping connections come with skilled labor, validation, inspection, and long commissioning times, as well as the workplace hazards associated with welding. Non-welded permanent mechanically attached fittings offer a viable alternative to welded piping systems that greatly reduces the time to commission piping systems through reductions in many of the time-consuming steps required in welding. Download Now
White Paper - Take Mobile Hydraulic Systems to a New Level
The introduction of digital ecosystems connecting electronic control hardware and software to the Cloud is catalyzing a new era of mobile machine and equipment design innovation. This is enabling OEMs across industries to develop customized solutions that digitally integrate hydraulic and machine controls with the Internet of Things (IoT). Download Now
White Paper - The Evolving Landscape of Commercial Battery-Powered Trucks
What’s driving the evolving landscape of truck electrification? What are the barriers, motivators and strategies for accelerating the electric transition? What insights and resources are available for today’s design engineers working to achieve industry disruption and evolution? For answers to these and other pertinent questions, read this white paper. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close