AMOT 10GEF, Operation And Maintenance Manual, Page: 77 / 80

77
Technical Data
OMMG00012 Rev 12 – NOV 2019
ENGINE OILS GEAR OILS
Oil CST Oil CST
SAE 5W 6.8 SAE 75W 22
SAE 10W 32 SAE 80W 46
SAE 20 46 SAE 85W 100
SAE 20W 68 SAE 90 150
SAE 30 100 SAE 140 460
SAE 40 150
SAE 50 220
9.1.5 Valve Sizing Calculations
Pressure Drop
The G valve is designed to produce minimal pressure drop. The normal
recommendation when determining the size of an AMOT G valve is a pressure
drop between 0.01 and 0.1 bar (0.145 and 1.45 psi).
Valve Flowrate
A Kv is the valve’s flow coefficient. It is defined as the number of cubic metres
of room temperature water that flows through the valve with a pressure drop
of 0.069 bar (Cv is the imperial coefficient). See the table below for examples
of Kv and Cv for the G valves:
2” 3” 4” 6” 8” 10” 12” 14” 16”
Kv 82 207 323 729 1296 2025 2918 3972 5187
Cv 96 242 378 851 1513 2364 3405 4635 6053
Note
Cvs are applicable to 90
°
rotor versions only. For 180
°
versions:
The basic formula to determine the
Kv of a valve is:
The basic formula to determine the
Cv of a valve is:
Dp
SG
Q Kv
=
Q
Dp
SG
Kv
= Flow (m
3
/h)
= Pressure drop (bar)
= Specific gravity of
fluid
= Valve flow
coefficient
Dp
SG
Q Cv
=
Q
Dp
SG
Cv
= Flow (US
gallons/min)
= Pressure drop
(psi)
= Specific gravity
of fluid
= Valve flow
coefficient
The formulae for finding flow (m
3
/h) or
pressure drop (bar) are shown below:
The formulae for finding flow (US
gallons/min) or pressure drop (psi)
are shown below:
Dp
SG
Kv Q =
SG
Kv
Q
Dp
2






=
Dp
SG
Cv Q =
SG
Cv
Q
Dp
2






=
2
90
180
Kv
Kv =