Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations MintJulep on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Pressure Vessel Testing

Status
Not open for further replies.

ClintUS

Mechanical
Joined
Jul 13, 1999
Messages
3
Location
US
Old Tester- diaphram pump, pressurizes 70 PSI / stroke then regens until vessel breaks.<br>
<br>
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.<br>
Both mediums are water.<br>
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.<br>
Problem: The old tester breaks vessels at 700 PSI + -<br>
The new tester breaks them at 500 PSI + - .<br>
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 ?<br>
<br>
Other factor - New uses threaded nipples and the old uses a air cylinder to clamp.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top