Thank you,Pierre and shvet.
Maybe for the PSV it is impossilbe to avoid acetylene choked flow. But for rupture disc it is possible to prevent acetylene choked flow from occuring with the larger relieving area than the required.
Is it right?
As AIGA 022/13 CODE OF PRACTICE ACETYLENE says,
6.4.3 Pressure relief devices
Acetylene vented from pressure relief devices should be discharged outside the building to an area specifically classified for acetylene where there is no risk of ignition. All discharge pipes or orifices to the open...
Hi,shvet,
Thanks a lot for your sharing.
According to the shown company best practices it depends on the user to determine whether the auxiliary piping should be considered.
Thank you shvet.
As you mentioned Note that usually wetted area of piping solely does not contribute enough relief load to exceed max vapor load of distillation column.
Is there any standard or best practice refers to this?
Thank you,Latexman.
I agree with you that the worst overpressure scenario of collumn isn't fire case usually.
But when calculate the relieving load of fire case for distillation collumn it excludes the auxiliary piping no matter what size is the piping?
Hi,all,
We all know that the external fire scenario is credible when distillation collumn is located below 25 feet.
But sometimes the distillation collumn is elevated beyond 25 feet with the purpose of avoiding the fire scenario.
So is it needed to consider the relieving load of external fire...
Thank you all for your kindly reply.
According to your reply I have summarized as below,
1. If no leak it is unnecessary to pull the actuated PSV offline
2. If the regulation requires it must be offlined to recheck
3. It depends on the fluid property
So my question is how to check whether it...
As the title says after psv reseating are there any regulations, standards and best practices which require the actuated PSV shall be offlined and tested.
Thank you for your answer in advance.
Hi, everyone.
When the relieving fluid is liquid is it necessary to choose the smaller one from the calculated relief rate and the normal flowrate?
Thank you in advance.
Thanks a lot for your kind reply and disucussion.
In my opinion it should be staggered to meet different overpressure scenarios' relief requirements without chattering or cycling.
But it is a little bit difficult for me to find the specific standard in which it is described to ask for...
Hi, danschwind&don1980,
Thank you for your kind reply. And please find the credible scenarios list and their relieving load respectively.
It is noted that the governing case is overfilling with relieving requirement of 187914kg/hr. So it is recommended that two identical PSVs be in service...
There is a case in which the required capacity is provided by more than one PSV.
Someone says the set pressures of multiple PSVs can be the same. But others say it should be staggered in order to prevent chattering.
So which is right?Thank you in advance
Pemi&Latexman
Thank you for your reply.
And the reference in which nozzle length occured is attached. Please refer it and look forward to your further comments. Thank you again.https://files.engineering.com/getfile.aspx?folder=81d48220-a0ee-4982-9492-3efaac7f24a3&file=nozzle_length.JPG
Hi, evergone.
When I read a reference material about two-phase flow PSV sizing the term of nozzle length arises several times. It comfuses me a lot to understand the paper very well.
Woulde you like to take a detailed explanation on the term?
Thank you in advance.
To don1980
Thanks a lot for your suggestion.
But this is my assignment from my department leader. He want me to be PSV sizing EXPERT through many case studies just like this case. So I have been trying my best to search related references which helps me finish the assignment.
But until now it...
to don1980
I can't agree with you more.
But I have to pose this post in the group because except me my colleagues have little knowledge about PSV.
And I have read many materials about PSV sizing for reactive chemicals. But those are general references for PSV sizing.
to avalveman
Thanks for your reply. The scenario for the vessel overpressure is external pool fire.
And what confuses me is whether DIERS method should be adopted to conduct PSV sizing.
As known TBHP is very active chemical sensitive to temperature.
Now it is required to size PSV for the storage tank in which 55%TBHP and 45%TBA is contained.
SO which method is appliable for the case?