E-Stop / ESD Button - Designation on P&ID

[kdcui]

I'm working on a process application (skidded / mobile process system) where we will have an E-Stop / ESD pushbuttons at a local operator panel.

I realize ESD = / = E-Stop however the team I am working with seem to use them interchangeably (and I keep having to clarify). The intent here is to trigger a ESD and bring the process to a safe state. If it matters, we are designing / implementing per IEC 61511.

In a previously life working on machine safety, we had a drawings for all the safety and e-stop loops - typically these were part of (or closely related to) the electrical schematics.

Now that I am working on a process application, there is debate on whether or not the E-Stop / ESD button should be on the P&ID. If yes, what reference designation should we give it? I've looked through ISA 5.1 and it is still unclear to me.

Furthermore, I am concerned that the electrical schematics will use a different reference designator and cause confusion.

We are early in conceptual design so electrical diagram and such have not been developed - we only have a P&ID, Instrument List, and very preliminary I/O List.

Looking for some input to help point me in the right direction.

Note: In our case, we are using an integrated safety PLC (S7 1500 Failsafe), so this PLC is both going to be the BPCS and the SIS. This could change depending on our HAZOP / LOPA outcomes.

Thanks.

 

[cardosocea]

To be honest, I did similar and called mine SIS-ES0199 and so on. I doubt that it's correct as per P&ID rules, but no one could tell me what it should be.

Also, create a separate P&ID for the SIS loop, the dotted lines showing the initiator and end devices clog drawings a fair bit.

As for the ESD used interchangeably, could be worse. Drilling rigs have both ESD and EDS and they're definitely not the same thing... as some poor ******* learnt when dropping equipment to the seabed. LOL

 

[glennz]

E-STOPs should be on the P&ID.

I believe "HSS" (hand safety switch) would meet the intent of the ISA letter table. Is that what you are looking for?

My company works in process too, but don't deal with SIS (rare in our industry). We do E-STOPS on P&IDs as a simple HS with 'E-STOP' text alongside the bubble.

Coordinating naming between design disciplines (i.e., P&IDs vs electrical's schematics) should be an integral part of your company's design process.

 

[kdcui]

E-STOPs should be on the P&ID.

I believe "HSS" (hand safety switch) would meet the intent of the ISA letter table. Is that what you are looking for?

My company works in process too, but don't deal with SIS (rare in our industry). We do E-STOPS on P&IDs as a simple HS with 'E-STOP' text alongside the bubble.

Coordinating naming between design disciplines (i.e., P&IDs vs electrical's schematics) should be an integral part of your company's design process.

Thank you! This makes sense and is exactly what I was looking for!