Thanks.
If you look at figure 4.20.3.4.(2) in NFPA 20-2010 the last line showns a minimum pitot tube pressure of 18 psig.
Does this means that the minimum pressure at the flow measuring location is 18 psig? FM global recommends a minimum of 10 psig.
Adding all pipe length, fittings and...
NFPA 20-2007 allows the designer to hydraulically size the pipe for the test header art. 4.20.3.4(2).
There's no mention of the acceptable pressure. Figure 4.20.3.4.(2) identifies the elements that must be included in the calculation, but there's no design critereas.
Should I consider that...
