Determine pipe schedule and rating 2

[Xssim]

Hi all, I would like to ask how does one determine the pipe schedule and rating according to the pressure and temperature of a fluid?

Thank you.

XS

 

[LittleInch]

Xssim,

I can see this is your first post here, but this is a very basic question which you really should be asking your supervisors, assuming you're not a student.

This is a simple question, but can be quite a complex answer as it depends on:

the fluid
the design code(s) in use
the actual pressure and temperature (high values on either can change the answers)
whether the fluid is considered inert or "lethal" or high purity
the material of the pipe (depends on many of the answers to the questions above
the corrosion allowance
the manufacturing tolerance of the pipe (if any)
the jointing mechanism
the manufacturing type of the pipe
the strength of the pipe

If you can define your question based on the items above then you might get somewhere, but normally it is expected that the OP does at least some work beforehand to try and get the answer themselves.

1/10

LI


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

 

[Xssim]

Hi Littleinch,

Thank you so much for the detailed explanation.

My senior colleague actually asked this question, and he gave me some more details this morning.

He wanted to know if a Schedule 40 pipe is enough for a 6" pipe carrying O2 at 20 bar, above ground, and he would like to know the flange sizing as well.

Thanks,
XS

 

[TGS4]

Of the list that you were provided above, you still need to provide:

the design code(s) in use
the actual pressure and temperature (high values on either can change the answers)
whether the fluid is considered high purity
the material of the pipe (depends on many of the answers to the questions above)
the corrosion allowance
the manufacturing tolerance of the pipe (if any)
the jointing mechanism
the manufacturing type of the pipe
the strength of the pipe

 

[KevinNZ]

Hi Xssim

Short answer for DN150 (6") Sch40 with 20bar, Maybe OK.
Long answer see TGS4's post.

 

[MJCronin]

Kevin, TGS4 et al ......

There are some standards that recommend using stainless steel in pressurized Oxygen service...

Special flanges and oxygen rated gaskets also suggested .....

MJCronin
Sr. Process Engineer

 

[EdStainless]

And special valves, regulators, gauges and a few other items.
All of the systems that I have worked with were either stainless or Cu.
I have watched an oxygen system burn (steel pipe), it isn't nice.

Try CGAnet.com and look at these
G-4 11 20 Mar 2015 Oxygen
G-4.4 5 26 Oct 2012 Oxygen Pipeline and Piping Systems


= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[LittleInch]

Xssim,

Liquid 0xygen or gaseos Oxygen?

Either way it really isn't something an inexperienced engineer should be messing around with and special precautions need to be used as many things which are inert in air burn fiercly in the presence of pure Oxygen.

What is your role in this design at the moment?

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

 

[Xssim]

Hi Littleinch,

It is for Gaseous Oxygen.

My role is in assisting my colleague in the initial design phase of the system.

Thanks and regards,
XS

 

[LittleInch]

OK, How about the rest of the information as noted by TSG4?

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

 

[MJCronin]

Like I said, and everyone else repeated .... Stainless Steel pipe.

And .... find someone with experience in the design, procurement, specification, cleaning and testing of pressurized oxygen systems.

Cleaning is extremely important .....

There are many details, including valve requirements, operators, etc that must be "just right" in oxygen systems

https://www.eiga.eu/index.php?eID=dumpFile&t=f&f=2464&token=445f73d8905379110b9c1795d62fd76aac05ac3d

Realize that when your MBA boss assigned this system to you, it was a lot like giving a loaded gun to a toddler...

My opinion only....

MJCronin
Sr. Process Engineer

 

[Xssim]

Hi Littleinch,

We are still in the process of obtaining the information as noted by TGS4.

Hi MJCronin,

Thank you so much for the advice.

My senior colleague has experience in this industry (ex-Linde) but is better versed for bulk oxygen systems. Our country only has standards for bulk oxygen systems, and we rely on the expertise and standards from NFPA, BS, EIGA, AIGA, and others.

For cleaning, we would be referencing this standard:

http://www.asiaiga.org/uploaded_doc...ipment for oxygen service_reformat Jan 12.pdf

Thanks and regards,
Sim

 

[TGS4]

If you don't have the necessary information, then the answer to your original question is "I don't know" until such time as the information is available. And that should be your answer to your boss, as well.

 

[GD2]

Xssim,
By your original question you seem to be a starter in the piping design. Even if you have received overwhelming response and guidance, be careful what you design and tell your boss. In a situation like you, I would prefer that you work under a senior experienced engineer and learn the trade. I don't know about your company set-up but designing something you don't know is a risk to people, equipment and company. I don't mean to discourage you but this forum won't teach you everything you should know. Show your work - calculation/report to a senior engineer before you endorse it.

GDD
Canada