Testing the emergency depressurization system of a Diesel HDT unit

[Richard62]

Has anyone experienced a test of the emergency depressurization system of a Diesel Hydrotreating unit (ULSD) with the objective to check orifice plate dimensioning and depressurization rates in an HDT unit about to shutdown (end-of-run) ? Is this a bad idea/proposal considering the risks involved ? Thanks for your comments.

 

[EmmanuelTop]

Testing ESD-1 is a common practice, typically done during commissioning/startup, but by no means limited to that time only. It is performed during CSU as one of the guarantee points before the plant can be handed over to the end user.

What risks are you anticipating? The purpose of ESD-1 is to eliminate the risks, not to generate them. If you suspect that ESD-1 cannot not be effectively executed, that is one big reason to evaluate the system and actually conduct the test.

Dejan IVANOVIC
Process Engineer, MSChE

 

[georgeverghese]

Running a high pressure EDP is always scary, no matter how many times you've done it before. Check everything you can before pressing the red button on this. If you find something in the design books and piping runs that could cause all hell to break loose, fix them first.

 

[plantprowler]

@george

Out of curiosity, any examples of the "somethings" you may have found during review that "could cause all hell to break loose"?

 

[georgeverghese]

I remember one case where one of the EDP ROs' was wrongly sized, and more than one case where flare piping supports were badly corroded.