Class A, B, C shutdown logic 1

[AlexWNZ]

Hi All,

I've been working with gas engine driven reciprocating gas compressors for a while now and I've never found which standard defines the way shutdown logic should be handled (i.e. class A, B, C shutdowns, the "B" and "b" timers etc).

It seems common across a bunch of vendor control systems (AMOT, Spartan etc) but with some slight differences between them.

Is this something that is in a standard somewhere or is it up to the vendor to make up their own? Any info would be greatly appreciated!

Thanks!

Alex from NZ

 

[horacio Torres]

Every compressor manufacture set their logic to protect their equipment...

companies witch request a compressor establish a basic safety switches, control logic, process conditions and shutdown in the equipment data sheet, but the final safety shutdown is set by the manufactures.


Horacio

https://www.linkedin.com/company/lagotuy/

 

[LittleInch]

It sounds like vendor specific descriptions.

I've never heard of class A B C shutdowns.

PetroChem plants typically have level 0 1 2 3 shutdowns which is fairly common, but what cause that is part of the design work.

Level 0 is usually a "push and run" button!

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[AlexWNZ]

Thanks for the feedback!

There is reference to what the shutdowns do in this PLC talk thread
[URL unfurl="true"]http://www.plctalk.net/qanda/showthread.php?t=66535[/url]

Its very muchly a skid based way of thinking (i.e. how the skid gets through its sequence logic and what shutdowns are applicable when (i.e. the low coolant pressure trip on a machine shouldn't be active when the machine is stopped otherwise it will never start). I haven't yet seen it applied to the wider process.

As mentioned before I'd be keen on understanding if this is codified under an industry standard, or if its just a convention most compressor / engine skid manufacturers have adopted.

Thanks!

 

[LittleInch]

It's just a convention.

Normally these would be determined in the cause and effect diagram/ logic.



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[1503-44]

ESD 0 Total emergency shutdown with abandon of platform
ESD 0.1 Black shutdown
ESD 1 Total plant emergency shutdown
ESD 2 Total process shutdown
ESD 3 Local unit shutdown

https://www.engstack.com/kb/recomme...ments-esd-mobile-offshore-drilling-unit-modu/

https://instrumentationtools.com/emergency-shutdown-system-philosophy/

https://www.law.cornell.edu/cfr/text/49/192.167

https://www.kenexis.com/compressor-station-safety-fundamentals/

https://www.chemengonline.com/reciprocating-compressors-startup-and-capacity-control-methods/

http://www.e-pneumatic.com/media/pdf/atlas-copco-ga-30-manual.pdf

https://www.processtechacademy.com/features-of-a-gas-turbine-gt-shutdown/

 

[LittleInch]

The 0,1,2,3 levels work for plants / rigs etc so maybe the individual vendors decided to use A, B, C in their internal logic to avoid confusion....

Inhibition of action during start-up is common for process systems but is normally carefully controlled as is inhibited ESD trips.



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[OpticControl]

At my site we use ESD 1, ESD2 and ESD 3. ESD 1 has the highest criticality and it's a full facility shutdown. ESD 2 initiates the shutdown for process units and ESD 3 initiates the shutdown of equipment. For the case of compressors, as ESD 3 on critical equipment will result in a ESD 1.
After reading your link to PLC Talk I believe these are just equivalent ways to refer to same shutdown levels. Our description is more aligned with @1503-44's reply.

I am not aware of any standard, such as ISA-84, IEC 61511, etc. that would mandate the nomenclature or labeling of shutdown
scenarios.

 

[gwalkerb]

Have you tried asking one of those vendors if there's a code basis, or if it's one of their own internal standards?

 

[AlexWNZ]

Hi,

Yes I did reach out to a vendor and it sounds like it is just a convention based off old AMOT functionality back in the 90s (Presumably this might become a standard some day!