7 replies to this topic

[phoenixmoca]

As the topic says why shall it be so?

[latexman]

Is it reasonable the majority of the time that the inlet pipe size be smaller than the inlet PSV flange?

Of course not, there would be lots of inlet pressure drop problems.

Therefore, that is why we have the rule.

[breizh]

Hi,

To add to Latexman's comments , consider reading the manufacturer's recommendation attached .

paragraph 6-3-2 related to pressure loss and unfavorable conditions 

Breizh 

[Bobby Strain]

Latexman,

 

        I wonder why my response was deleted? And your response is probably a guess.

 

Bobby

[latexman]

Bobby,

 

Idk, I see no sign you posted previously in this thread.  It was not where removed posts are archived, and those cannot be deleted by breizh and I.

[Bobby Strain]

Latexman,

    Maybe I failed to post it after I entered my comments. So, I'll repeat it.

 

phoenixmoca,

    Maybe you can do some research and get back to us. And I shouldn't waste my time even with this response. Your search will likely reveal that there is no answer to your query. It's like that query "Why did the chicken cross the road?"

 

Bobby

Edited by Bobby Strain, 28 July 2021 - 09:21 AM.

[Pilesar]

As safety devices, pressure relief valves are rated to flow a specific rate. Their performance is based on the relief orifice size and the flowing fluid characteristics. Installation standards are designed to not compromise the expected PSV performance. Following guidelines from ASME, ISO, API etc eliminates some variables that might be difficult to otherwise account for. Would a smaller inlet pipe than PSV flange mean that the vessel were not adequately protected? Not necessarily. But it would mean the installation did not conform to good engineering practice and the overpressure protection would be suspect. A smaller inlet piping than the PSV inlet flange does affect the PSV performance. Historical problems with vessel overpressure has left little appetite for compromising a safe PSV installation.

 

I appreciate the open communication between Bobby and latexman. Lizards communicate by doing push-ups, but that would not be very effective in this forum.

[phoenixmoca]

Thank you all for your kindly response. I have gotten the point.