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Multi-stage valve

Values for calculation

$ Q_{max} $ $ \mathrm{m^3/s} $
$ D $ $ \mathrm{mm} $
$ P_1 $ $ \mathrm{Pa} $
$ P_2 $ $ \mathrm{Pa} $
$ T $ $ \mathrm{°C} $
$ ρ $ $ \mathrm{kg/m^3} $
$ P_{SV} $ $ \mathrm{Pa} $
$ μ $
$ d $ $ \mathrm{mm} $

Calculation

Velocity in valve

$$v_{max}=\cfrac{4\cdot 10^6\cdot Q_{max}}{π\cdot D^2}$$

Number of stages

$\text{if }\ \left(P_2-0.6\cdot P_{SV}\right)/0.4>P_1$
$$n_{s}=1$$
$\text{else if }\ \left(\left(P_2-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4>P_1$
$$n_{s}=2$$
$\text{else if }\ \left(\left(\left(P_2-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4>P_1$
$$n_{s}=3$$
$\text{else if }\ \left(\left(\left(\left(P_2-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4>P_1$
$$n_{s}=4$$
$\text{else if }\ \left(\left(\left(\left(\left(P_2-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4>P_1$
$$n_{s}=5$$
$\text{else if }\ \left(\left(\left(\left(\left(\left(P_2-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4>P_1$
$$n_{s}=6$$
$\text{else if }\ \left(\left(\left(\left(\left(\left(\left(P_2-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4>P_1$
$$n_{s}=7$$
$\text{else if }\ \left(\left(\left(\left(\left(\left(\left(\left(P_2-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4-0.6\cdot P_{SV}\right)/0.4>P_1$
$$n_{s}=8$$
$\text{else}$
$$n_{s}=9$$
Stage
Maximum pressures between stages
Pressure difference between the stages
The flow area
Number of holes
$ S $ $ P_{max-stages} $ $ ΔP_{stages} $ $ A $ $ I $
$ \mathrm{\ } $ $ \mathrm{Pa} $ $ \mathrm{Pa} $ $ \mathrm{m^2} $ $ \mathrm{\ } $
No data

$ P_{max-stages}\ [\mathrm{Pa}] $
No data
$ S\ [-] $
Maximum pressures between stages

$\text{if }\ S=1$
$$P_{max-stages}=P_1$$
$\text{else if }\ S=2$
$$P_{max-stages}=\left(P_1\cdot 0.4+0.6\cdot P_{SV}\right)$$
$\text{else if }\ S=3$
$$P_{max-stages}=\left(\left(P_1\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)$$
$\text{else if }\ S=4$
$$P_{max-stages}=\left(\left(\left(P_1\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)$$
$\text{else if }\ S=5$
$$P_{max-stages}=\left(\left(\left(\left(P_1\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)$$
$\text{else if }\ S=6$
$$P_{max-stages}=\left(\left(\left(\left(\left(P_1\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)$$
$\text{else if }\ S=7$
$$P_{max-stages}=\left(\left(\left(\left(\left(\left(P_1\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)$$
$\text{else}$
$$P_{max-stages}=\left(\left(\left(\left(\left(\left(\left(P_1\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)\cdot 0.4+0.6\cdot P_{SV}\right)$$

$ ΔP_{stages}\ [\mathrm{Pa}] $
No data
$ S\ [-] $
Pressure difference between the stages

$\text{if }\ S=n_{s}$
$$ΔP_{stages}=P_{max-stages}-P_2+\left(n_{s}-1\right)\cdot\left(\left(P_2-0.6\cdot P_{SV}\right)/0.4-\left(P_{max-stages}\right)[n_{s}]\right)/n_{s}$$
$\text{else}$
$$ΔP_{stages}=P_{max-stages}-P_{max-stages}[i+1]-\left(\left(P_2-0.6\cdot P_{SV}\right)/0.4-\left(P_{max-stages}\right)[n_{s}]\right)/n_{s}$$

$ A\ [\mathrm{m^2}] $
No data
$ S\ [-] $
The flow area

$$A=\cfrac{Q_{max}}{μ\cdot \sqrt{2\cdot \cfrac{ΔP_{stages}}{ρ}}}$$

$ I\ [-] $
No data
$ S\ [-] $
Number of holes

$$I=\left\lfloor\cfrac{4\cdot A}{π\cdot d^2\cdot 10^{-6}}\right\rfloor$$

Requirements

$$ \cfrac{D}{50}\geq d $$ $$ \cfrac{4\cdot 10^6\cdot \max\left(A\right) }{π\cdot D^2}< 0.5 $$