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There is a requirement of having CCVs (Critical Check Valves) identified and set to period inspection & maintenance. Identification is required to be made during HAZOP studies.
Please share the best practices here as how CCVs are identified during HAZOP of the facilities, the basis.

See the requirement is very clear as mentioned in API 570 now that identification and maintenance is mandatory. Identification comes as a team input and yes that is through a process hazard study. We make sure once a facility is revalidated for its hazard operability, CCVs are validated and updated to Maintenance team to drop, inspect and maintain.

Heard about Class 1 check valves as well.
Any idea what are the basis for such classification?

Identification of CCVs is required to be liked with process safety study, HAZOP the one here.
The way to pick the critical check valves starts with the basic principle of its importance in avoiding an unacceptable consequence upon failure.
To start with, wherever a check valve has been taken as a safeguard to mitigate the consequence in a hazard operability study, pick that up, tag that and attach a maintenance plan.
And once that is done, you can confidently comply with API 570 requirement which is now a mandatory one.

Please let me know if you need more details on this.

Another aspect is that mechanical personnel should also get involved in identifying critical check valves. This because outside HAZOP discussions as well, any valve which is critical in normal operation should also be picked up as critical. A check valve installed on the discharge of a spare pump (safety critical service) responsible to avoid reverse flow towards pump should be inspected.

arcpro wrote: 05 Jun 2025, 15:54 Identification of CCVs is required to be liked with process safety study, HAZOP the one here.
The way to pick the critical check valves starts with the basic principle of its importance in avoiding an unacceptable consequence upon failure.
To start with, wherever a check valve has been taken as a safeguard to mitigate the consequence in a hazard operability study, pick that up, tag that and attach a maintenance plan.
And once that is done, you can confidently comply with API 570 requirement which is now a mandatory one.

Please let me know if you need more details on this.

Here you can read this basic well written article on CCVs identification, and inclusion in inspection and maintenance.

Now this was a good piece.
Thanks ben.

Just checking if identification has already been done at some sites, to share best practices.

ben wrote: 07 Jun 2025, 06:27 Here you can read this basic well written article on CCVs identification, and inclusion in inspection and maintenance.

Once identified, how to set the inspection frequency of critical check valves?
Any reference on that particular requirement?

That is another part where inspection & maintenance needs to provide some inputs.
Identification itself would be the first step only.
I learnt from some of my colleagues about Class 1 check valves being inspected at least every 10 years.

novice123 wrote: 16 Jun 2025, 14:54 Once identified, how to set the inspection frequency of critical check valves?
Any reference on that particular requirement?

See Class 1 check valves as classified by Shell are the ones upon failure to restrict the reverse flow can result in an overpressure scenario upstream.
This is what we learnt as part of their DEP 80.45.10.11.
But check valves which upon failure can result in process chemistry detrimental for the material of construction should also be considered as critical.
Or if a process upset is identified during HAZOP upon its failure should also be picked up.
Identification should be done very carefully to make sure that none of the consequences is ignored.
This then should follow with their tagging and rest of the maintenance work to plan, inspect, and maintain.

tuan wrote: 18 Jun 2025, 15:07 That is another part where inspection & maintenance needs to provide some inputs.
Identification itself would be the first step only.
I learnt from some of my colleagues about Class 1 check valves being inspected at least every 10 years.

novice123 wrote: 16 Jun 2025, 14:54 Once identified, how to set the inspection frequency of critical check valves?
Any reference on that particular requirement?