where
V = the kinematic viscosity in centistokes
C = the approximate constant in (mm
2 /t)/t (from Table 14)
t = the flow time from the test
Reid Vapor Pressure
This test is the standard test for low-boiling-point distillates. It is used for naphthas,
gasolines, light cracked distillates, and aviation gasolines. For the heavier distillates
with vapor pressures expected to be below 26 psig at 100
F, the apparatus and
procedures will be different. Only the Reid vapor pressure for those distillates with
vapor pressures above 26 psig at 100
F is described here. The apparatus used for
this test is shown in Fig. 5.
Table 14 Viscometer SIL details
Size
number
Approximate
constant
a
Kinematic
viscosity
range, ctt
Inside
diameter of
tube R, mm
Inside diameter
of tubes E and P,
mm
Volume
of bulb C,
ml
0C
0.003
0.6–3
0.41
4.5–5.5
3.0
1
0.01
2.0–10
0.61
4.5–5.5
4.0
1C
0.03
6–30
0.73
4.5–5.5
4.0
2
0.1
20–100
1.14
4.5–5.5
5.0
2C
0.3
60–300
1.5
4.5–5.5
5.0
3
1.0
200–1,000
2.03
4.5–5.5
5.0
3C
3.0
600–3,000
2.68
4.5–5.5
5.0
4
10.0
2,000–10,000
3.61
4.5–5.5
5.0
a
Constant is in (mm
2
/t)/t
Bourdon Pressure
Gage
Screw Connection
B
A
Fig. 5 A Reid vapor pressure
apparatus
Quality Control of Products in Petroleum Refining
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