AMOT 10GEF, Руководство по эксплуатации и обслуживанию, Страница: 76 / 80

76
Technical Data
Rev 12 – NOV 2019 OMMG00012
9.1.3 Valve Weights
The approximate weights of the valve/actuator are as follows in kg (lb):
2
in
3
in
4
in
6
in
8
in
10
in
12
in
14
in
16
in
Cast Iron
32
(71)
48
(106)
60
(132)
86
(193)
146
(328)
187
(420)
295
(663)
435
(977)
575
(1292)
Bronze
34
(75)
51
(112)
67
(148)
100
(225)
164
(368)
209
(470)
319
(717)
485
(1089)
671
(1507)
9.1.4 Viscosity Correction
For the selection of valves for more viscous fluids than water, the following
must be calculated:
Viscosity:
Find the viscosity of the fluid in which the valve is to operate. The viscosity is
normally expressed in Centistrokes. Where ISO oil is used, the grade number
is also the viscosity eg: ISO VG46 is 46 Centistrokes at 40
°
C (110
°
F).
Viscosity Correction:
By using the correction graph below, the flow coefficient correction factor can
be established. The correction figure obtained from the graph should then be
multiplied by the original flow coefficient which can then be used in the
standard valve sizing formulae (Sect 9.1.5).
Example: From the graph below, 100CST = correction factor of 0.68
0.68 x flow coefficient = corrected flow coefficient (Kv or
Cv).
Fig 26 Viscosity Correction Graph
Some approximate viscosities (CST) of SAE oils at 40
°
C (110
°
F) are shown
below, based on leading oil manufacturers published data: