Material Selection of Ethylene Storage Tank
Material Selection of Ethylene Storage Tank
(OP)
Dear all.
Hello.
I have a question.
In attached process data sheet, design temperature of ethylene storage tank is -40 C, and depressurizing temperature is -89 C. But the designer selected LTCS (with minimum temp.: -45C) and noted that this material should sustain depressurizing condition!!! How could is this possible?
Hello.
I have a question.
In attached process data sheet, design temperature of ethylene storage tank is -40 C, and depressurizing temperature is -89 C. But the designer selected LTCS (with minimum temp.: -45C) and noted that this material should sustain depressurizing condition!!! How could is this possible?
RE: Material Selection of Ethylene Storage Tank
Steve Jones
Corrosion Management Consultant
www.linkedin.com/in/drstevejones
All answers are personal opinions only and are in no way connected with any employer.
RE: Material Selection of Ethylene Storage Tank
Owners policy: its obvious! No brittle fracture.
I couldn't fully get your point. LTCS cannot stand - 89 c temperature, so did the designer something Wrong???
RE: Material Selection of Ethylene Storage Tank
Not many new storage tank spheres are built these days .... It would be be very interesting to discuss your reasons for your choice of a sphere ...
Vacuum insulated liquid Ethylene Storage Tank are commonly available in different sizes and configurations for smaller volumes. The inner tank is stainless steel and the outer is low-temperature carbon steel with vacuum and perlite in annular space. Both vertical and horizontal cylindrical tanks are used
Large Liquid ethylene storage tanks are designed as a single wall flat bottom tank without a roof, The outer tank is a flat bottom tank, and Roof is domed steel. The roof supported on the outer tank wall with a suspended deck for the Insulation.
https://www.ethylenetank.com/
See page 10 of this document
http://tomatoenc.com/_public/images/common/tomatoe...
MJCronin
Sr. Process Engineer
RE: Material Selection of Ethylene Storage Tank
So the owner needs to be presented with the technical justification of why steel is considered acceptable at that temperature.
Steel can "stand" -89 deg C if the stresses it experiences at that temperature are sufficiently low. Which takes us back to the point made in the paragraph above. As stated previously, many operators would set the minimum design temperature as -89, equating it to the minimum metal temperature. The design codes would do the rest.
Steve Jones
Corrosion Management Consultant
www.linkedin.com/in/drstevejones
All answers are personal opinions only and are in no way connected with any employer.
RE: Material Selection of Ethylene Storage Tank
Also it does say "Equipment" to be capable, it doesn't say "tank"....
Design temp is clearly written as -40. If whoever wrote the data sheet wanted the design temp to be -89 then they had the chance to say so.
I suspect that the issue is one of temperature vs pressure, so at 0 barg, stresses are a lot lower goes the argument. At 5 bar they are probably somewhere in between.
Also LTCS is rather vague.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Material Selection of Ethylene Storage Tank
Steve Jones
Corrosion Management Consultant
www.linkedin.com/in/drstevejones
All answers are personal opinions only and are in no way connected with any employer.
RE: Material Selection of Ethylene Storage Tank
Or will you disrespect us by dropping this thread ?
We may not answer any more of your questions if we are disrespected ....
MJCronin
Sr. Process Engineer
RE: Material Selection of Ethylene Storage Tank
RE: Material Selection of Ethylene Storage Tank