Controlling flow using PID or other method?

[misamark]

Hi;

Scenario 2:
I had one similar (maybe!) problem - to controll temp. in one wessel, which is heated by hot steam (168degC or about 10bars of presure); but in this time I have used PD controller; there is Very simple mathematics how to make this without using PID; and I obtained to control temp in a range of +/- 1deg;
What I had not used standard PID? I could`nt etsblish quickly open and close this steam on/off valve; then, I used mathematics to establish MOMENT of ON and OF state of the valve; After; you need to estimate gain, scan time and D parameter; maybe sounds complicated, but there isn`t.
If anybody is interested, just reply to me!

regards for everybody!!

 

[lsis]

SENARIO 1:
I thing that you have to use a triod valve and bypas pipe with 4-20 mA control of valve not pid required.
The inverter on a pump is not accept solution.
Senario 2
Th epid control is rhe best solution.

LS