×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

#### Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

# API 650 -tank's internal pressure 3

## API 650 -tank's internal pressure

(OP)
hi everyone

i've foun this formula : p=8*A*Fty*tan(10)/sfD*2

but the problem is about the A : the area resisting the compressive force as illustrated in Figure F.2

i coudn't know that area

### RE: API 650 -tank's internal pressure

Please define where you got that formula.

Also fig F2 has many different details, but no "A"

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

### RE: API 650 -tank's internal pressure

(OP)
hi,
thanks for responding

my tank is with a conic roof and a central column
with H=8m and D= 9.67m

i want to calculate the internal pressure of the tank and i found in the AL.12.2 of api 650 this formula : p=(8A*fty*tan(teta)/(sf*d^2))+RhTh

the problem is :

A:is the area resisting the compressive force as illustrated in Figure F.2 except that 16t shall be replaced by
56ts Fty

first of all i want to know if this rule is the correct one to use in order to calculate the internal pressure,
if it's right then i wanna know the area resisting the compressive force

btw i've opened figure F.2 but it's not clear for me

### RE: API 650 -tank's internal pressure

Appendix AL is for aluminium tanks. Is your tank aluminium?

Anyway area A is the hatched area as described in section F3 is my reading of the code.

Normally you would use the calculation and procedure in section F.

But if this is an existing tank it will state the design pressure on the tank name plate or the tank drawings.

What are you trying to do exactly?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

### RE: API 650 -tank's internal pressure

(OP)
Let me make this straight for you

I am a student in my last university class and i have to end it with a project
And mine is : conception of a tank for liquid sulfur following the api 650 instructions

My tank's material is acier s355

Thank you

### RE: API 650 -tank's internal pressure

S355 is steel so the AL section doesn't apply. You usually work out what pressure you need then design the tank accordingly rather than the other way around.

API 650 isn't great for tanks with internal pressure.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

### RE: API 650 -tank's internal pressure

(OP)
All right thanks for the help

### RE: API 650 -tank's internal pressure

First decide, based on operating needs, if the tank is pressurized at all.
Liquid sulfur tanks will fall under Annex M due to temperature requirements.
The specific gravity of liquid sulfur is greater than 1, so include the extra for that.
Usually, liquid sulfur tanks will include a hefty corrosion allowance as well, 1/8" or 3mm or more.
If the required internal pressure exceeds the weight of the roof plates, it will fall under Annex F as well.
If the tank is more than around 12m diameter, it will likely have a supported cone roof with rafters and center column. Under that, a self-supporting roof, either cone or umbrella.

### RE: API 650 -tank's internal pressure

(OP)
I am remaking the tank's conception with the same dimensions
The diameter is 9.67m but with supported cone roof and a center column

### RE: API 650 -tank's internal pressure

2
Liquid sulfur should not be stored in a re-used API-650 tank ..

The API-650 code is not appropriate for this high temperature, high density, corrosive service

The Young Original Poster is being set up as the Engineer of Blame (EOB) for this MBA fever dream ....

MJCronin
Sr. Process Engineer

#### Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

#### Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

#### Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a partâ€™s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

# Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!