Sunday, August 9, 2009

ELLIPSOIDAL HEAD THICKNESS CALCULATION ( PREVEDAS)

Last week I was posting about calculation of shell thickness in pressure vessel, now I sharing ellipsoidal head thickness calculation base on ASME VIII div 1.



The required thickness of a dished head of semi ellipsoidal form, in which half the, minor axis (inside depth of the head minus the skirt) equals one-fourth of the inside diameter of the head skirt, shall be determined by



Where;



t = minimum required thickness of head after forming, in. (mm)
P = internal design pressure (see UG-21), psi (kPa)
D = inside diameter of the head skirt; or inside length of the major axis of an ellipsoidal head; or inside diameter of a conical head at the point under consideration, measured perpendicular to the longitudinal axis, in. (mm)
S = maximum allowable stress value in tension as given in the tables referenced in UG-23, psi (kPa)
E = lowest efficiency of any joint in the head; for hemispherical heads this includes head-to-shell joint; for welded vessels, use the efficiency specified in UW-12

Same as previously, I also make the computer program (software) to make easier for us in conducting calculation. Please see picture bellow.



This program also can show and print the report of calculation, please see sample report bellow.



Please download sample program in http://www.ziddu.com/download/6044170/EllipHeadCalc.rar.html

5 comments:

  1. HI,
    my name is Daniel

    I am doing a script on the asme boiler and pressure vessels code.

    Your formula helps a lot. But I can't find the "E" lowest efficiency and the "S" maximum allowable stress value in tension. I am suppose to find it in a table but I don't have them ether. can you show me how I can find them?

    I would appreciate your help a lot!

    tnx

    Daniel

    ReplyDelete
  2. Hi Daniel,

    You Can download in following Link :

    http://www.ziddu.com/download/10190199/Section8PartUG-23.pdf.html


    http://www.ziddu.com/download/10190229/Section8PartUW-12.pdf.html

    ReplyDelete
  3. Please show your Email,
    I will send you Link for Table 1A.

    ReplyDelete
  4. plz sir if u can help me finding the diefferent between the dished head and the elliptical head on sketch and from the point view of thickness calculation .. thank u so much .
    u can send me any documentation through my mail :
    d_msw_9002@hotmail.com

    ReplyDelete
  5. Dear Salama,

    I have been send link to your email.

    Dedi

    ReplyDelete