Blind thicknesses 1

[sunpipe]

I'm using the equation from ASME B31.3, Equation 15, paragraph 304.5.3 to determine blind thicknesses. The results are similar to thickness values in API 590 and ASME B16.48 (both entitled Steel Line Blanks). I used the max operating pressure as the design pressure in the equation. But will these thicknesses be adequate for hydrostatic test pressures of 150% of design without yielding?

 

[jte]

sunpipe-

API-590 was converted into B16.48. The blanks for B16.48 were designed in accordance with the rules of ASME B31.3-1987. See the foreword (page iii) of B16.48 1997.

To answer your question directly, see B16.48 part 8 which includes in part Line blanks may be subjected to system hydrostatic tests at a pressure not to exceed 1.5 times the 100°F rating rounded off to the next higher 25 psi.

See also B31.1 part 104.5.3(B).

For testing at pressures higher than those provided by B16.48 and B31.1, you may encounter some yielding. You may find a paper presented at the 2005 ASME Pressure Vessels and Piping conference interesting.

http://store.asme.org/product.asp?c...apers&category_name=&product_id=PVP2005-71164

You might be surprised at how much pressure a slip blind can handle if you are willing to tolerate some (say 1/8" or the thickness of a typical gasket) residual deflection.

jt