VPL
Though I am in Europe, our regulations and procedures are following yours and then are almost identical.
Yes, we have been doing stroke time testing for a long time, tipically measuring times from the control room based on lights.
Here, we started doing diagnostic testing because of the...
Due to our recent beginning in diagnostic testing on AOVs we have some questions about if we are trying to go too far in the data acquistion. This is particularly important in the case of the 'stroke times'. The questions are:
1.- Is Diagnostic Testing used to take measures of the stroke...
I am not able to find any information related to this positioner on the web.
Does anybody know something about de Bailey AP-53 positioner or where to obtain some information from?
Thanks
Both of you might be right saying that the construction is similar to other actuators in the industry. I am just familiar with a few designs.
The actuator has a piston and an accumulator, maybe like others. The difference that I find with respect to the ones that I know is its capability to...
Has any one out there had experience with DYNACTAIR pneumatic actuator for 1/4 turn valves?
Note that this is a very unique actuator design.
The output torque appears to be lower than expected in the spring direction. No preventive maintenance since the preoperational tests, 26 years ago...
Thanks, steamdog.
However these valves must perform also a modulating function. For that reason still a positioner is needed.
I see two options:
- find an adequate positioner
- modify the control loop to acomodate two different paths: one for on/off and other for control.
Patricia
Answering to your questions ...
- They are pneumatic.
- The opening time is 20 sec.
- The closing is not a safety-function but it is the desirable normal position.
It is relevant to know that the actuator volume is high.
tHANKS
Let me explain our situation. Possibly someone else went through a comparable situation and might be of help.
Some present safety related valves were just conventional control valves in origin. Because of a licensing change these valves needed to be qualified as safety related. Not only a...
Let me explain our situation. Possibly someone else went through a comparable situation and might be of help.
Some present safety related valves were just conventional control valves in origin. Because of a licensing change these valves needed to be qualified as safety related. Not only a...