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!

*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

Pressure Vessel Testing

Pressure Vessel Testing

Pressure Vessel Testing

Old Tester- diaphram pump, pressurizes 70 PSI / stroke then regens until vessel breaks.

New Tester- I designed a feed back loop analog control to regulate the pressure gradient at 80 - 100 PSI / Sec. Using a booster cyl., the pressure is gained linearly and adjusted 100 times a sec.
Both mediums are water.
Both sample lots used in the testers are from the same materila batch ( PolyPropelene ) from the same process, at the same manufacture time and from the same press.
Problem: The old tester breaks vessels at 700 PSI + -
The new tester breaks them at 500 PSI + - .
Could there be a stress re-allignment going on in the old test that is not present in the new, due to the rest between pulses. ( rest time is approx. .2 sec., Pulse is approx. .3 sec. ) which is allowing the vessel to fail at a higher pressure ?

Other factor - New uses threaded nipples and the old uses a air cylinder to clamp.

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


eBook - Functional Prototyping Using Metal 3D Printing
Functional prototypes are a key step in product development – they give engineers a chance to test new ideas and designs while also revealing how the product will stand up to real-world use. And when it comes to functional prototypes, 3D printing is rewriting the rules of what’s possible. 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