Exempt Hydraulic Oil Accumulator From API 510 Inspections

[ReliaEng2008]

Hello there. This question is regarding the inclusion of an equipment to an inspection program per OSHA's PSM/Mechanical Integrity (29 CFR paragraph 1019.119(j)), considering the applicable RAGAGEP Codes and Standards.

I have an 2.5 gallon (volume less than 1 cubic feet) hydraulic oil accumulator that is part of the hydraulic system of a rotating equipment. It is ASME design and has a U1 form. The MAWP is 2000 psi. Material of construction is 316L SS.

As you can imagine, this pressure vessel is not a concern (assuming the rotating equipment is maintained properly). There is basically no expected damage mechanisms.

I would like to exempt this equipment from inspection requirements of API 510. I am reading the exemption section of the Standard and I cannot find any options to exempt this equipment. Even though it is part of a rotating equipment skid, I don't consider it an integral part of a rotating equipment (for example, a built-in heat exchanger inside a compressor would be an integral part of the rotating equipment). Even though the volume is less then 1.5 cuft, since the design pressure is more than 600 psi, it looks like I will have to include this equipment in my inspection program, although I don't expect inspections to be of much value.

Any thoughts?

 

[SwinnyGG]

I don't consider it an integral part of a rotating equipment

OK... but does OSHA?

 

[ReliaEng2008]

OSHA does not define what is consider an integral part of rotating equipment.

API 510 provides a few examples. From API 510 Annex A (Code Exemption): Pressure containers that are integral parts or components of rotating or reciprocating mechanical devices, such as pumps, compressors, turbines, generators, engines, and hydraulic or pneumatic cylinders where the primary design considerations or stresses are derived from the functional requirements of the device.

Considering this accumulator "an integral part or component" of rotating equipment would exempt this equipment from API 510 inspection requirements.

 

[SwinnyGG]

That's what I was getting at.

Just because YOU don't define it as such doesn't mean it can be defined as such under the code, and is thus exempt.

"The primary design considerations or stresses are derived from the functional requirements of the device."

This sounds like a nearly exact description of the accumulator you're considering here.

 

[r6155]

National Board Inspection Code 2021 edition must be applied.
The requirements of the NBIC supersede general and specific requirements of other inspection codes, standards, and practices.

Regards

 

[ReliaEng2008]

The requirements of the NBIC supersede general and specific requirements of other inspection codes, standards, and practices.

No sir. Not in my industry. API 510 is and has been the Standard followed by every single facility I have dealt with for inspection requirements of pressure vessels. Link

 

[r6155]

@ ReliaEng2008
You are some confused.
1) Do you still think that your vessel (2000 psi) can continue in service without any inspection?
2) Do you have the NBIC 2021 edition?
3) You refer an article edited in 1995- We are in 2022.

Regards

 

[ReliaEng2008]

1) Do you still think that your vessel (2000 psi) can continue in service without any inspection?

@r6155

It is not a matter of what I think. I am asking the other users of this forum if there is any option for exempting this equipment from inspections that I am not aware of. The process for exempting a vessel from inspection is not willy-nilly, there are procedures to follow and forms to be filled out. If I cannot find a valid inspection exemption for this vessel, it will be inspected.

Considering that this equipment is too small for internal inspections, the only inspection that will be performed is a visual inspection. And since the material of construction is 316 SS, and the service is noncorrosive, a visual inspection will not be of much value. And considering that there are no expected damage mechanisms, there will be no nondestructive testing planned for this equipment either.

 

[r6155]

@ ReliaEng2008

Contact a pressure vessel engineer.

Regards

 

[SwinnyGG]

I am asking the other users of this forum if there is any option for exempting this equipment from inspections that I am not aware of

There IS a mechanism for exemption that you are disregarding because of the way you are choosing to interpret 510.

The exemption includes the word 'integral'; it does not include the word 'internal'.

This accumulator is part of a hydraulic loop; are you worried about exemptions for the pumps, motors, cylinders, etc which also share this hydraulic loop? The cases of all of those components are exposed to the same pressures as the accumulator, and each of those devices is also a pressure vessel. Whatever this piece of rotating equipment is, you purchased it as a single line item; if you remove the accumulator, does it cease to function correctly? If the answer to that question is yes, then the accumulator is integral to the equipment and is thus exempt.

 

[r6155]

@ SwinnyGG
Do you interpret that inspections are not required for components of the hydraulic loop as you mentioned (pumps, motors, cylinders, etc )?
including this pressure vessel (2000 psig)?

Regards

 

[SwinnyGG]

In this case, there's no 'interpretation' on my part at all.

API 510 is very clear that hydraulic pumps, motors, cylinders, and the plumbing which carries fluid between them (such as this accumulator) are not subject to inspection per the pressure vessel code. They are governed by their own, separate codes (ie API 570 for piping which I'm assuming OP is familiar with).

3. Pressure containers that are integral parts or components of rotating or reciprocating mechanical devices, such as pumps, compressors, turbines, generators, engines, and hydraulic or pneumatic cylinders where the primary design considerations or stresses are derived from the functional requirements of the device.
4. Any structure whose primary function is transporting fluids from one location to another within a system of which it is an integral part (that is, piping systems).
5. Piping components such as pipe, flanges, bolting, gaskets, valves, expansion joints, fittings, and the pressure-containing parts of other components such as strainers and devices which serve such purposes as mixing, separating, snubbing, distributing, and metering or controlling flow as long as the pressure-containing parts of these components are generally recognized as piping components or accessories.

API 510 governs wholly owned and used vessels (IE not public). The only pressure vessels of any kind to which NBIC applies in the petrochem world are boilers, and we're not talking about a boiler. NBIC does not apply.

 

[r6155]

@ SwinnyGG
You are also confused.
See NBIC 2021. Do you have it?

Regards

 

[SwinnyGG]

You are wrong. NBIC does not apply to this case.

 

[r6155]

@ SwinnyGG
You don't answer my question, therefore
I consider that you do not have NBIC 2021 and consequently you interpret that this pressure vessel (2000 psig) does not require any inspection.

Regards

 

[ReliaEng2008]

You are wrong. NBIC does not apply to this case.

I second this. I have years of experience in my industry (chemical and petrochemical) and the inspection requirements that we have to follow have always been API510 for pressure vessels (together with API570 for process piping, and API653 for Atmospheric storage tanks).

Anyways, this pressure vessel operates at 2000 psi, has a diameter of more than 6''. It looks like it can't be exempted.

 

[chicopee]

What is the position of the jurisdiction in your State about pressure vessel inspections? If you are unable to contact that jurisdiction then contact the commercial insurance company that provide Boiler and Machinery coverage for information. Being an ASME pressure vessel NBIC would apply when repairs are required as well as the appropriate documentation concerning the repairs.

 

[SwinnyGG]

You don't answer my question, therefore
I consider that you do not have NBIC 2021 and consequently you interpret that this pressure vessel (2000 psig) does not require any inspection.

a
Fun fact.. no one on this forum works for you, and consequently is not required to answer your questions.

I actually do have a copy of NBIC 2021. Here, let me do what you always do in threads like this:

Read (slowly) NBIC 2021. The reason it doesn't apply in this case is in there.

 

[r6155]

Thanks for answering my question, now I know you have the NBIC 2021.
So in your judgment this pressure vessel (2000 psi) doesn't need to be inspected. Never. There are no risks, as if it did not exist.
And as you say "The only pressure vessels of any kind that NBIC is applied to in the petrochemical world are boilers."
I do not see that you have experience in inspection
Thank you again.

Regards

 

[SwinnyGG]

So in your judgment this pressure vessel (2000 psi) doesn't need to be inspected. Never. There are no risks, as if it did not exist.

Ah.... no. I most certainly did not say that.

If you're going to be condescending, you at least need to make sure that you're precise.

Go read my posts again. Slowly.