Given Pressure drop ratio in Fisher control valve handbook

[Kingkona167]

So I am confused in the Fisher control handbook and other sources such as in this pdf -

http://www.documentation.emersonprocess.com/groups/public/documents/reference/d351798x012_11.pdf

The value for Xt (pressure drop ratio) that they use in the example problems do not match the Xt I am reading from the chart. For example on pg. 642 in the pdf linked there is an example problem where they state that the Xt for an 8-inch Design V250 valve at 100% travel is .137. However, when I look at table 4-2 on pg. 645 I see a value of .18. I'm ripping my hair out at this, can anyone explain?

 

[HPost]

Looks like typo...

 

[danw2]

In Emerson/Fisher's ASME/ISA/IEC VALVE SIZING guide, Catalog 12 Index, dated February 2013, here,
[

http://www.proconexdirect.com/wp-content/uploads/2013/09/Valve-Sizing-Coefficiencts_Catalog-12.pdf

]
the XT for an 8 inch V250-1 (page 263 pdf) is listed as 0.14, two digit precision rounded up from 0.137.

My gut feeling is that the examples in that document are 30-40 years old (the same examples are in the sizing section of catalog 12 dated 1992).
[

http://www.documentation.emersonprocess.com/groups/public/documents/catalog/cat12_s2.pdf

]
Fisher's been doing this a long time now.

At one time there were probably tables with 3 digit precision values but the examples don't get edited over time.

I've gotta concur with the 'typo' assessment.