Steam flow rule of thumb 150 fps

[Bill3752]

I am reviewing some relief valve calcs done by an engineering firm for a manufacturer about 10 years ago. In several instances the value of 150 fps was used to calculate the steam flow limit through pipe (and therefore max case through RV). This was done in several cases representing pipe diameters from 2 - 6 inches, and (I believe) for several upsteam pressure cases. Anyone have any experience with this? The fact that it was used over a diversity of cases, and by a handful of engineers, makes me think this must be some rule of thumb number with which I am unfamilar.

 

[Latexman]

I'm not sure your question is in the right section or not, but take a look at this:

thread311-191447

Have you tried using the site's search functionality? That's how I found the thread above.

Good luck,
Latexman

 

[Bill3752]

Thanks Latexman. Actually I had found the referenced post, and I am somewhat familar with the erosion issue. I probably ought to clarify what I stumbled across. While checking some relief valve scenarios evaluated by an engineering firm about 10 years ago, I ran into several instances wherein they assumed the maximum steam flow through a pipe (and therefore to the inlet of the RV) was 150 fps. Thanks for your help.

 

[zerosum]

I don't have my Crane TP 410 with me but somewhere in there next to a nomograph for figuring pressure drop in steam lines is a small table with recommended best practice max steam velocities for several applications. Check if those numbers don't fit the calculation sheets you are reviewing.