Emerson Exchange 365

Our client has a DVC6200 with SOV vent solenoid on instrument air line to the DVC6200.  (a typical scenario 6 from the DVC6200 documentation). The SOV provides the safety function, the DVC6200 is there to allow partial stoke testing. The subject of this post is related to proof of the Solenoid vent device, NOT the process block valve as provided by the DVC6200 Partial Stroke Test PST.

I read the article on the subject linked here, regarding the third paragraph. See below my interpretation of how this could be achieved manually (using the SIS logic solver and AMS monitoring), but I would be interested to know if there is anyway to integrate activation and detection into a SIS logic solver to give a simple feedback of success or not. 

https://www.emersonautomationexperts.com/2006/safety/checking_your_s/

So you build a mechanism upstream of the final SOV Vent valve LSDO block to provide a 1 scan pulse (say 100ms, the SIS Module scan rate).   You would then detect the DVC6200 diaphragm pressure drop for the short period coinciding with this LSDO pulse, provided the signature pressure drop is detected then you can say the SOV is not seized and it is able to vent the diaphragm of the DVC6200.

I see this as a manual procedure. The signature pressure drop is not integrated back into DeltaV SIS logic solver for test success/failure evaluation.

The question is: has anyone tied the activation of the pulse into the feedback pressure allowing an automatic PASS/FAIL to be evaluated by SIS logic. Essentially the question is whether the DVC6200 diaphragm pressure can be read back by the SIS logic solver and used as feedback to the pulse to evaluate success or failure.

It is accepted that the high frequency pulse would have to be short enough to prevent full closure of the process flow line to prevent disturbance of the downstream process.

Thoughts welcome.

Thanks,

Neil