Frequently asked questions regarding RP13C ?>

Frequently asked questions regarding RP13C

1. What is the D100?
a. The D100 cut point of a screen is the particle size at which no particles will pass
through the screen.
b. D100 is a single number determined from a prescribed laboratory procedure the
results of the procedure should yield the same value for any given screen.
c. The D100should not be compared in any way to the D100 value used in RP13E.
d. The method used in RP13C provides only the D100 value with no provision for
D16, D50, or D84 values.
2. What does the API Screen Number tell us?
a. The API Screen Number corresponds to the API-defined range of sizes into which
the D100 value falls.
3. What does the API Screen Number NOT tell us?
a. The API Screen Number is a single number that defines solids separation potential
under specific test conditions. It does NOT define how a screen will operate
on a shaker in the field as this will depend upon several other parameters such
as fluid type & properties, shaker design, operating parameters, ROP, bit type, etc.
4. Will a screen with a D100 of 172m remove solids finer than 172m?
a. By definition, every particle of the D100 size or coarser will be discarded.
b. In practice, some portion of solids finer than 172m may be removed.
5. Why is there such a large variance between the old and new labeling values?
a. The biggest variation is due to the shift from using D50 to D100.
b. The previous test procedure(RP13E)measured the distribution of the apertures in the
screen. RP13C uses a physical and repeatable test using actual solids (dry aluminum
oxide) which measures the coarsest particle that can pass through the screen.
6. Should I use the old screen number or the new API Screen Number when
ordering replacement screens?
a. Although some companies are changing their part numbers to reflect their conformance
to RP13C, others are not. It is therefore best to specify the RP13C value
you want.
7. Should I screen with a finer screen now if what used to be called a “200
mesh” screen is now labeled APl 120?
a. Users are advised to determine the screens that work best in their applications
regardless of what the new API Screen Number happens to be.
8. What is the practical value of RPC13C to the end user?
a. RP13C provides an unequivocal procedure and benchmark for comparing
different screens.
b. The primary intent of RP13C is to provide a standard measuring system for


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