# Effective closing time factor

## Values for calculation

$D$ $\mathrm{mm}$
$Q_{max}$ $\mathrm{m^3/s}$
$H$ $\mathrm{m}$
$g$ $\mathrm{m/s^2}$
$K_{Q-valve}[1]$
$K_{Q-valve}[2]$
$K_{Q-valve}[3]$
$K_{Q-valve}[4]$
$K_{Q-valve}[5]$
$K_{Q-valve}[6]$
$K_{Q-valve}[7]$
$K_{Q-valve}[8]$
$K_{Q-valve}[9]$
$K_{Q-valve}[10]$

## Calculation

### Velocity in valve

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

### Theoretical pressure in the valve at full opening

$$Δ_h=\cfrac{v_{max}^2}{2\cdot g}\cdot \left({\min\left(ζ\right)}+1\right)$$

### Pressure parameter

$$p=\cfrac{Δ_h}{H}$$

$$0 < p \le 1$$

### Effective closing time factor

$$c_{ef}=0.1/\max_{i=1}^{10}{\left(Q_p[i]-Q_p[i+1]\right)}$$

$$c_{ef}\le 1$$
Stroke from open position
Flow coefficient
Loss coefficient
Reduced free flow area in the throttle control system
Relative flow
$s$ $K_Q$ $ζ$ $f_r$ $Q_p$
$\mathrm{\%}$ $\mathrm{ }$ $\mathrm{ }$ $\mathrm{ }$ $\mathrm{ }$
No data

$K_Q \mathrm{[-]}$
 No data
$s\mathrm{[\%]}$

$ζ \mathrm{[-]}$
 No data
$s\mathrm{[\%]}$

$$ζ=\cfrac{1-K_Q^2}{K_Q^2}$$

$f_r \mathrm{[-]}$
$Q_p \mathrm{[-]}$
 No data
$s\mathrm{[\%]}$

$$f_r=\cfrac{K_Q}{K_{Qmax}}$$
$$Q_p=\cfrac{f_r}{\sqrt{p+f_r^2\cdot \left(1-p\right)}}$$