Slug DLF=2

Hello Fellow Stressers!!

I believe that the DLF=2 is for an instantaneously applied constant load (not harmonic or impact load).

However, it is considered a common practice to apply DLF=2 in Slug. My understanding is that slug is an impact load, not a constant load.

Warm Regards,

A DLF of 2 for a slug may not be applicable. Depending on the length of the slug, and the response characteristics of the system, the actual magnification of the load may not be 2. Further, the magnification of the load varies according to the natural frequencies extracted for the system.

I suggest a dynamic analysis instead of assuming a value of 2.0.

If you're giving me an infinite range of piping configurations and an infinite range of slug speeds, densities, and lengths, then I'll say that any of the above might be considered appropriate, depending on your situation.

F2 = DLF * F1.

F2 = dynamic analysis force that results in stress S.
F1 = static analysis force that results in stress S.
DLF = Dynamic Load Factor

Any kind of multiplier for F2 performed in a dynamic analysis is a safety factor, not a DLF.

If you're asking for a DLF for any and all configurations, I will agree that 2.0 gets thrown around quite a bit. But I doubt anyone has compiled a book of DLFs for different piping configurations. It'd be useful to us.

Thanks Michael & Richard.

Warm Regards,