Internal pressure and external pressure in pressure vessel

[ekosusilo]

Dear all,

Could you please explain to me about pressure in pressure vessel, when we should apply internal pressure? and when we should apply external pressure for our pressure vessel. What the dimension of PV should be our consideration? or there are other consideration?

Thanks,
Echo

[bw1]

are you a mechanical engineer?

[ekosusilo]

No i'm a piping engineer, but now i should design tank with diameter 9m and high 13.5, the client want the tank based on ASME Sec VIII Div.1. I already read the ASME Sec VIII Div.1, except the wind and seismic, maybe the high also should be the consideration? or there is a high limitation to determining the pressure?

Thanks,
Echo

[FATHI]

The question was

No i'm a piping engineer, but now i should design tank with diameter 9m and high 13.5, the client want the tank based on ASME Sec VIII Div.1. I already read the ASME Sec VIII Div.1, except the wind and seismic, maybe the high also should be the consideration? or there is a high limitation to determining the pressure?

I have refered to Bednar Book = Pressure vessel Handbook
See attachment for some extracts of that book


Thanks,
Echo

--------------------

Now Mr. Duazo2009 said
You Don't know what you're talking about..in designing a pressure vessels, design ,pressure and temperature should not be assumed.. in a certain equipment operating pressure and temperature are always given and there's a formula to calculate the design pressure and temperature, you have to clarify what kind of pressure is it whether it absolute pressure or gauge pressure... the way you're are expalaining,
my answer = you miss my point , I was talking about another face of the problem, e.g = Loads, pressure , seismic , weight..and how to combine them , also telling that API is not suitable here

it seems that you don't know how to design...

my answer = I am 55 years old , spend more 20 years doing vessels , tanks , pipe stress etc for Shell , Exxon and Lloyds (Design assessment and approval ) and I am also ...for your information an ASME member since 1987 , I guess you were at school at that time.
Do you think I could stay in the business without being able to do it ... ,
Now, if you want to teach people as you pretend , first do not attack them , and please remain polite and respectfull , do not take things personal , we are here to learn from each other , nothing more , so respect the others and stop answering me
and attacking me, In my faith only Allah can judge me , if you see me using a a wrong formula or a wrong drawing , simply correct me without personal attack
that you are just refering to the entire codes but you don't know which section and paragraph it is found .. isn't it..
my answer = see above , ...do you now me ? have we met ? have we worked together ? are you an asme member ? are you a cousin of Bednar or Moise ? have you published something ?have you heard then about ethics ? is this what they teach home ? are going to rise kids this way ? do you still have friends ? can you communicate with other people ?.. you see it is easy to attack when hiding behind a screen ?
so my overall assesment regarding your reccomendation is absurd! and i repeat don't pretend that you know pressure vessel design..
my answer = it is your righ to talk !! I have no pretention ,We are always learning ..and its nice to stay humble and modest ,thats all..
then stop attacking , and respect the other .. End of discussion , please do not answer me anymore , but try to answer the thread and focus on helping by being more Constructive and proactive , and open to others ..and sorry to say = less agressive

Take note: data sheet will be made after finalizing the design which is the results of your calculations.
My answer = in the place where I am , first process data sheet is prepared ( With design condition , major dimensions, generic material ..) , then Mechanical data sheet is made with a basic drawing , showing major thinkness and loads ,.., then a requisition is prepared , the Vendor or manufacturer will make his own calculations and review all loads , he is responsible and liable for the mechanical design
Is it different on your job ???

anyway please focus on subject on not on the attacks , keep your energy positive and let people appreciate your collaboration .

Now if interested = Start reading the attachment and then you may comment ...other nonsense I do not need it

[duazo2009]

The question was


--------------------

Now Mr. Duazo2009 said
You Don't know what you're talking about..in designing a pressure vessels, design ,pressure and temperature should not be assumed.. in a certain equipment operating pressure and temperature are always given and there's a formula to calculate the design pressure and temperature, you have to clarify what kind of pressure is it whether it absolute pressure or gauge pressure... the way you're are expalaining,
my answer = you miss my point , I was talking about another face of the problem, e.g = Loads, pressure , seismic , weight..and how to combine them , also telling that API is not suitable here

it seems that you don't know how to design...

my answer = I am 55 years old , spend more 20 years doing vessels , tanks , pipe stress etc for Shell , Exxon and Lloyds (Design assessment and approval ) and I am also ...for your information an ASME member since 1987 , I guess you were at school at that time.
Do you think I could stay in the business without being able to do it ... ,
Now, if you want to teach people as you pretend , first do not attack them , and please remain polite and respectfull , do not take things personal , we are here to learn from each other , nothing more , so respect the others and stop answering me
and attacking me, In my faith only Allah can judge me , if you see me using a a wrong formula or a wrong drawing , simply correct me without personal attack
that you are just refering to the entire codes but you don't know which section and paragraph it is found .. isn't it..
my answer = see above , ...do you now me ? have we met ? have we worked together ? are you an asme member ? are you a cousin of Bednar or Moise ? have you published something ?have you heard then about ethics ? is this what they teach home ? are going to rise kids this way ? do you still have friends ? can you communicate with other people ?.. you see it is easy to attack when hiding behind a screen ?
so my overall assesment regarding your reccomendation is absurd! and i repeat don't pretend that you know pressure vessel design..
my answer = it is your righ to talk !! I have no pretention ,We are always learning ..and its nice to stay humble and modest ,thats all..
then stop attacking , and respect the other .. End of discussion , please do not answer me anymore , but try to answer the thread and focus on helping by being more Constructive and proactive , and open to others ..and sorry to say = less agressive

Take note: data sheet will be made after finalizing the design which is the results of your calculations.
My answer = in the place where I am , first process data sheet is prepared ( With design condition , major dimensions, generic material ..) , then Mechanical data sheet is made with a basic drawing , showing major thinkness and loads ,.., then a requisition is prepared , the Vendor or manufacturer will make his own calculations and review all loads , he is responsible and liable for the mechanical design
Is it different on your job ???

anyway please focus on subject on not on the attacks , keep your energy positive and let people appreciate your collaboration .

Now if interested = Start reading the attachment and then you may comment ...other nonsense I do not need it

Mr. Fathi.

For your info.

yes Mr. Fathi i am a member of ASME / PSME and a a reistered and Licensed Mechanical Engineer, the file you've attached here is extracted from a textbook only without any permission from the author / publisher to extract...no need to argue with you because the reality is, you really don't know.. you're just relying only in one textbook which has never and could not not be used as a reference in manual design calculation even in Compress and PV Elite software.. and to tell you frankly.. you don't know pressure vessel design.. i will be impressed if you would say that you're using a Pressure Vessel Handbook by: Eugene F. Magyesy as your reference... the way you answered it seems that you really don't know what you are talking about..

P.S. don't let myself not to answer you because you're not my boss and even my superior... you're just an ordinary person who want to gain more information from others..

Regards,

[dimas anugrah]

dear eko.
please read PV handbook for your first book, then ASME Sect. VIII for next book.

[deyprasen]

dear eko
ASME Sect. VIII is only for Horizontal Vessels and not for Vertical vessels. Use API 650 for the design or IS -803

[duazo2009]

dear eko
asme sect. Viii is only for horizontal vessels and not for vertical vessels. Use api 650 for the design or is -803

you're wrong, read also asme bpvc sec. V111 div. 1 & 2..

[ekosusilo]

Dear all,

Thanks you for your advice...

Regards,
Eko

[FATHI]

Tanks = API 650up to 2.5 psi design pre , which is low
API 620up to 15 psi design pre , which is also low

Seismic and wind are treated differently in API ( See for instance appendix E in API 650 ..)
---------------

Now = other vessels and COLUMNS as per ASME VIII
design pressure to determine the thickness , a bit similar to your piping in B31.3

based on = circumferential stress = P*R/ t
Note = if you have external pressure there an other additional check stated in ASME

longitudinal stress due to pressure = 0.5 * circumferential stress

You have to check =

stress = (longitudinal stress due to pressure) +/- (stress due to wind ) - (stress due to own weight )

stress = (longitudinal stress due to pressure) +/- (stress due to earthquake ) - (stress due to own weight )

They are textbooks in this site , go there and read atleast some basics, for instance =
Pressure vessel design handbbok by Bednar
or
The pressure design manual by Moise
or CAST book

Also ASME VIII div & , in its appendix L , has some top good examples

Above is implemented in software such as PV elite, or Compress but it important to understand what you are doing and before jumping onto a software

take care and good luck

[duazo2009]

Tanks = API 650up to 2.5 psi design pre , which is low
API 620up to 15 psi design pre , which is also low

Seismic and wind are treated differently in API ( See for instance appendix E in API 650 ..)
---------------

Now = other vessels and COLUMNS as per ASME VIII
design pressure to determine the thickness , a bit similar to your piping in B31.3

based on = circumferential stress = P*R/ t
Note = if you have external pressure there an other additional check stated in ASME

longitudinal stress due to pressure = 0.5 * circumferential stress

You have to check =

stress = (longitudinal stress due to pressure) +/- (stress due to wind ) - (stress due to own weight )

stress = (longitudinal stress due to pressure) +/- (stress due to earthquake ) - (stress due to own weight )

They are textbooks in this site , go there and read atleast some basics, for instance =
Pressure vessel design handbbok by Bednar
or
The pressure design manual by Moise
or CAST book

Also ASME VIII div & , in its appendix L , has some top good examples

Above is implemented in software such as PV elite, or Compress but it important to understand what you are doing and before jumping onto a software

take care and good luck

hi,

ASME SECTION VIII has three divisions, 1, 2, & 3 you have to specify where your requirement are applicable. it's not easy to say and reccommend any formulas without determining the application, it might be in ASME SEC VIII Div. 2 or Div. 1 check first.. the formulas you've mentioned here is absolutely wrong and incorrect. that is not the first step, you have to determine first the allowable stress of material to be used at design temperature and ambient temperature as per ASME SEC. II-D table 5A.. then use the formula mentioned in ASME SEC VIII depending in which division you are using.. whether DIV. 1 or 2.. take note thickness calculation formula for shell in this two division are different.. so be careful.

Thanks,,

[FATHI]

hi,

ASME SECTION VIII has three divisions, 1, 2, & 3 you have to specify where your requirement are applicable. it's not easy to say and reccommend any formulas without determining the application, it might be in ASME SEC VIII Div. 2 or Div. 1 check first.. the formulas you've mentioned here is absolutely wrong and incorrect. that is not the first step, you have to determine first the allowable stress of material to be used at design temperature and ambient temperature as per ASME SEC. II-D table 5A.. then use the formula mentioned in ASME SEC VIII depending in which division you are using.. whether DIV. 1 or 2.. take note thickness calculation formula for shell in this two division are different.. so be careful.

Thanks,,

Of course I have assumed
design pressure + Design temperature both max and min + corrosion allowance + materials are known and should figure in the process data sheet , befor making a mechanical data sheet or any mechanical sizing

Now you tell me or tell us where are the mistakes , by refering to the codes or text books
I will be glad to learn and correct myself befor induced others in errors

Thanks