Wetted surface for torispherical head

[skrath]

I want to size a safety valve for a vertical cylindrical styrene storage tank with torispherical heads. According to API-521, for fire case, Q=21000*F*(Wetted Area)^0.82. How to determine wetted area for the head. Can anybody please help?

 

[BenThayer]

try 0.918 D^2. i found this in some notes but cannot find a source for it. since it is more than pi/4 D^2, it may be close.

 

[BenThayer]

if you sneak a peek here you get 0.93 D^2

http://books.google.com/books?id=pe...&hl=en&sa=X&oi=book_result&resnum=1&ct=result

 

[quark]

Can't you get it from the blank diameter of the plate before forming?

 

[skrath]

Thank you Ben for your reply.
Could you tell me, what will be the wetted surface area of torispherical heads of a partially filled bullet?

Thanks in advance.

 

[gr2vessels]

skrath,
Calculating the partially filled torispherical head of your bullet:

http://www.duckjoelee.com.ne.kr/documents/tankdok2.doc

or

http://www.cheresources.com/integrals_in_excel.shtml

Howzat,

Cheers,
gr2vessels

 

[nouanda]

quark:

you can't, since the plate is distorded during forming. Final area is greater than the plate area.