Relief valve in filters

[axl2005]

Hi
I am instaling a new filter in my process (cartdriges filter), but I am not sure if we need to install a relief valve. We will use this filter to remove small particles (solids) from apyrophoric material and this product is moved using cyclohexane or other solvent. Where can I find information related this topic, codes?
Temp max: 80 F, Press max: 40 psig
Thanks for your support

 

[roker]

hello,

API 520 AND 521.

REGARDS

 

[TD2K]

You first need to determine what are the possible causes the filter could be overpressure. API 520/521 are a good start as Roker suggests.

If the filter is a pressure vessel (which is likely) then the pressure vessel code requires you to provide a pressure relief valve or other acceptable device (rupture disk, etc). That would be a another good place to review, most PSV vendor's manuals will have exerpts from the Pressure Vessel Code describing the code's requirements.

That said, I've seen filters without PSVs where the only overpressure case was if the filter was blocked while it was full of liquid and subsequently there was a surrounding fire. Several companies will not provide a PSV for this situation as their procedures call for any blocked in equipment to be drained of liquid. No liquid, nothing to vaporize is the argument used. This has been a point of much discussion on this site

 

[mechtimeng]

You may have another option if the filter is a stamped vessel. You may try to see if you can reclassify the vessel as ASME B31.3 piping. By reclassifying the filter as pipe, you would not need to provide a PSV to protect it. There are procedures available in API 510, and API 570 to determine if your filters would qualify for reclassification to piping.

good luck!

 

[EGT01]

Just to clarify a point, reclassifying the filter as a pipe so that it falls under ASME B31.3 doesn't mean that you don't need relief protection. ASME B31.3 does require that piping be protected from overpressure. By reclassifying the filter as a pipe, the assumption would be that the filter would be protected by whatever means that the remaining piping system is protected and a separate PSV may not be needed for the filter just to satisfy the language in the pressure vessel code.

 

[brainstorming]

TD2K gave good explanation on the subject and I think u would look for his solutions
Therefore,
From my experience I have seen all filters have PSVs (including the spare filters) I think the reason of having PSV in such case is that fire.
I would think there should be PSVs for filters if the code still consider the filter like a vessel.
Please let's know what you have done on this.

Regards