Quick Opening Closure ASME VIII D.1 #2500 1

[LupusLupis]

Hope somebody can help me to fix a problem, I got request to supply a QOC "bandlock type" size 40" to be tested to 600bar ASME VIII D.1 UG35 design and U stamped.
Every time i try to calculate it with FEM analysis it shows that in critical sections VON MISES stress it's about 3 or 4 times the ASME maximum allowable stress (I use ASTM A105 or equivalent for HUB, DOOR and SEGMENT with allowable <20000psi), is it possible to use A694F65/70 with a different allowable stress=0.8*Yield taking in consideration that it's in needed the U stamp?

Thank you for help

 

[dmac21]

Would suggest that you contact the manufacturer as I believe that the Closure is out of their design range. Contact information for GD can be found at

http://www.gdengineering.com

The Bandlock style closure relies on the use of an elastomeric seal and which restricts the maximum design pressure. Have seen them supply ANSI 2500# rated equipment.
For a 600 BarG application, you will probably have to rely on a closure having a metal to metal seal and do not believe that this is an available feature with the Bandlock.
Would suggest either the Oceaneering brand or

http://www.nevisenterprise.com

as alternate.
As for the question regarding use of high yield strength material, yes this can be done BUT as these high yield materials are not recognized by Code the closure could not be furnished with the Code stamp. Tough application as on this size / design pressure the resultant thicknesses or parts will probably become a limiting factor on available yield strength as thicker the cross section, the lower the yield strength achieved during the quench and temper process.
Hope this helps

 

[LupusLupis]

Thank you for help dmac
but I already contact many QOC suppliers and they replied that are not able to supply this QOC with ASME U stamp, maybe I have to ask for a clamp type QOC.