Safety Valves for Pressure Vessels and Heat Exchangers

[Inchtain]

Dear Gents,

We are going to perform a general turnaround for an NGL Plant.

I would like to know if it is mandatory by code/standard to dismantle the safety valves pertaining to the equipment planned for inspection during the period of the shutdown for inspection and setting verification.

As far as I know, API 510 allows a 5-yr interval for safety valves inspections. Can we refer to that if we skip their inspections to save time?

If the safety valves haven't been recalibrated at the time of the equipment inspection, can be that a cause for the rejection of certifying the equipment by a third party?

Thanks and best regards,

 

[NovaStark]

Do you have any previous inspection history for the valves ?

Depending on the service and operational history you may find that those in clean service may not require frequency internal inspection and recertification. However, those in dirty service may.

Some valves such as those on boilers may require annual testing/certificaiton based on the laws of your country. Insurance requirements may deem certification during turnarounds when all other equipment are certified.

While API 510 can be a good starting place, you may be better off performing a risk assessment or FMECA to determine the overall risk as these would be classified as critical safety devices.

 

[ShabsRBI]

It is a good practice to Overhaul and Recalibrate the Pressure Safety Valves with the equipment shutdown. This will give an opportunity and confidence in maintaining the Plant safety devices in functional order. API-510 is a good code to refer for all Inspection activities but a risk assessment shall be performed if any extension is required. Normally for steam boilers, all the PSV are followed with Boiler T&I, which is less than 5 years.

 

[GD2]

OP,
NovaStark had directed you in the right direction.
You need to check the following to evaluate your inspection interval requirement in order of priority:
1. Any requirement by Your local Regulator.
2. API 510 - this is an recognized inspection code accepted by most Regulators.

RBI API 580 is also high recognized by Owner companies and Regulators. This works when you are working in a large facility with limited resources.

To answer your last question, check the Equipment Manufacturer's manual if it requires the safety valve calibration with the equipment inspection? Note that API 510 is a pressure vessel code. If you are talking about a skid-mounted equipment such as pump, compressor etc, the Code doesn't cover these equipment and you should follow the equipment inspection interval.

 

[r6155]

The use of a manifold (2 ways) for 2 safety valves should be considered.

 

[The Obturator]

While API-510 is pressure vessel relevant, as indicated by GD2, it also refers to API-576 which is specifically for inspection of Pressure-relief Devices.

Key to your ongoing maintenance schedule, is to build up a dossier of overhaul and report any issues found. This in turn will ultimately determine your future schedules. API-576 gives guidance on this.

Note that there is a separate forum for Safety Relief Valves.

 

[r6155]

Why is ASME XIII not mentioned?
ASME XIII Rules for Overpressure Protection

Regards

 

[The Obturator]

ASME XIII is new build not maintenance which is what this discussion is about.

 

[r6155]

No maintenance may be performed if ASME XIII has not been previously applied.

 

[The Obturator]

@r6155 Please explain your last comment it makes no sense.

 

[r6155]

@ The Obturator

1) As an inspector, I need complete documentation for the valve before scheduling inspection and in-service maintenance. ASME XIII requirements must be included in the original data book that the valve manufacturer sends to the user.
2) I also need documentation for the pressure vessel.

Regards

 

[The Obturator]

OK So you're discussing inspection rather than the maintenance subject of the original post.

Granted that any Pressure-relief Device or vessel should follow appropriate requirements, whether this is ASME I, VIII, XIII etc. Not all regions (countries) are mandated to use such codes, but many do and many follow without the final ASME Code stamping.

As an Inspector you should also be aware that ASME Coded (ie., stamped) vessels and equipment, are subject to the National Board Inspection Code NBIC - NB-23, after initial construction and this code will include maintenance amongst other criteria such as installation and piping.

NB-23 Is a post construction code applicable to repair, alterations, maintenance etc. It is very comprehensive and provides good user advice on many issues after construction.

NB-23 Part 4 in particular, is for Pressure-relief Devices which refers back to the appropriate ASME Code (I, VIII, XIII etc.), and is originally based on the earlier mentioned API-576.

To further the OP's original query, shown/attached below is an extract from NB-23 Part 4 tabling test intervals for Pressure-relief Valves - It is recommended to read and understand the context around this in NB-23 to appreciate how to determine your own maintenance schedules.

 

[r6155]

OP say “We are going to perform a general turnaround for an NGLPlant.”
This means inspection, obviously.
Visual Examination is an inspection.
No maintenance can be carried out without a prior visual examination (inspection).