rika kose
Chemical
- Jun 11, 2019
- 62
Not sure if it is the right place to ask this question.
We have a butterfly valve. the valve has to be controlled at different opening positions. Valve vendor seleted double acting actuator (pneumatic). positioner (elector-pneumatic). Valve vendor guaranteed that the valve's fail safe position is "stay in the last position".
But one techincian insists that if electricity is down, the valve will not remain in position. The eletricity is only signalling on the positioner. I don't belive that positioner is acutually controlling the valve
since there is no instrumentation engineer available, I need some help from internet.
Thanks in advance.
We have a butterfly valve. the valve has to be controlled at different opening positions. Valve vendor seleted double acting actuator (pneumatic). positioner (elector-pneumatic). Valve vendor guaranteed that the valve's fail safe position is "stay in the last position".
But one techincian insists that if electricity is down, the valve will not remain in position. The eletricity is only signalling on the positioner. I don't belive that positioner is acutually controlling the valve
since there is no instrumentation engineer available, I need some help from internet.
Thanks in advance.