Climate Screen for Vessel Protection

Can you approach the members of your company who signed off on this project?

Where else have you looked?

Who else have you asked?

What else have you done, if anything, to discover what the vendor needs to know?

The, "unapproachable" client will surely discover the deficiency.

My guess is that you are hopelessly lost and doomed to fail.

Do you have money to hire a consultant?

i am available. PM me.

I might accept the guy's query if he would approach me. But, I just don't know what he wrote.

Bill Moss Tents could design a really cute one.

You will need to determine which directions need to be protected against (above, one or two sides?), and also design wind loads.

EPC?

Climate screen?

Like a vessel housing?

Would a container do?

What sort of vessel?

For those who did not understand EPC- its Engineering, Procurement and Construction. This is a vertical vessel with 231 bar DP and 85° DT. It has length of 9670 mm tan to tan. Vessel thickness is about 162 mm. Please share related data.

Just be polite. Alright? I think, you could get the manufacturer's support on this.So first step is to contact them.

I'm guessing this is some sort of containment vessel that needs to be protected from direct sunlight, or perhaps sand storms? Without knowing the details of what measure of protection this "vessel" requires, it makes little sense to suggest a solution....You could use a stainless steel screen for longevity....

http://www.twpinc.com/wire-mesh-material/stainless-steel

Which part are you?

E?

P?

Or C?

My guess is that you are B. Bean counter.

Maybe he just means insulation...

http://www.foamguardinsulation.com/products/tanks/

http://www.paroc.com/solutions-and-products/solutions/process-industry/heat-exchangers-and-vessels

Maybe!

I never heard the term vertical vessel.

We do not have any pertaining data for your problem. We only half understand where the problem is in the first place

Is there an engineer there? DP and DT are acronyms that might need better definition. What is that measurement tan to tan?

Given the thickness of the vessel I would say you no need no stupid climate screen.

Its like saying you need a umbrella for a tank!

Take a tarp instead!

There's always dp/dt.

Hmmm a few questions here

The main issue is that a climate screen is a vague and useless description.

You are in Kuwait and so the main issues with climate are going to be sun and sand I would imagine.

DT = 85C (Design Temperature and DP = DEsign Pressure) which as far as I recall is the Black Body Temp in Kuwait ie the temperature to which a body in the sun will be heated. This is the usual lowest Max DT that is used. If the vessel is good for the black body temp then it doesnt need sunshine protection.

But how do you protect from a sand storm. I would have thought only solid metal sheeting would work. By the way what is the personal protection temperature and the operating temp int he vessel? Do you need protection to stop operators burning themselves? If so would this insulation service as climate screen?

Does the screen have to be fixed to the vessel or could it be fixed to the structure - 100mm is pretty close fitting.

ASME VIII vessel code (normally the one used in Kuwait) applies for Texas and other very wet places so the limited rain in Kuwait is not a factor in requiring protection.

Has this vessel already been fabricated? If so you are lost because retroftting rackets to a thickwall vessel like this is expensive and risky.

Unfortunately my Kuwait experience was FEED and so climate screens were not part of the scope. But as noted elsewhere this is a meaty vessel and I cannot see the need for such a device

IdeaSmith the terms are common in the oil and gas business and like the OP I'd probably use them without thinking too

Vertical Vessel - cylindrical vessel in which the axis of the circular cross section is vertical (ie a cylinder stood on its end). They typically have 2:1 dished end ( I cant explain that mathematically except to say its sort of half an ellipse and its depth is half that the equivalent hemisphere would be)

Tan - Tan is the length of the cylindrical section where the dished ends are welded on. It is the usual way of referring to the length of a vessel. In my side of the work (chemical engineer for oil contractor) we would never refer to the overall length of a vessel; just say is 9620 Tan - Tan with dished ends.

Metal temperature ordinarily isn't a problem unless above 650dF, but much lower temperatures can increase the pressure of the contained substance. The OP doesn't say, but is probably guarding against high temperature inside the vessel. Insulation could do that, but a "simple" screen is probably less costly. A typical set-up would be a frame outside the vessel (by 150mm ~~6" in this case), with fabric curtains attached by grommets and lacing, or clips of some sort. Such a structure would need to be designed for the usual loads; wind might be the most significant in Kuwait.

I dont get the temperature to be deg Celsius. It just says DT=85.

Your deduction maybe correct but it could be something else!

At the moment we are guessing.

Tan to tan length might not work when making up a "climate screen".

If the vessel is standing on its dished end then there might be more needed than just a climate screen.

Maybe this is something to look into

Jus saiin!

True it does not say but with pressure in bar and length in mm °C is the logical unit.

Also as I noted above I have used this as a Design Temp for ambient vessels based on the black body temperature in Kuwait.

Naturally a vertical vessel is supported by a skirt or legs (its odd realising how many actions that I think are obvious and fundamental are nothing of the sort). Typically there will be a liquid outlet nozzle at the bottom on the vessel in the centre of the dished end and this needs a flange and an elbow to connect the piping. These sorts of vessels either stand on three legs at 120° separation or a skirt which is a hollow cylinder of steel.

I do not understand your meaning when you say that the tan to tan length might not work when making up a screen. If you mean that it wont cover all the vessel then yes thats true. But for people in my part of the business its how we would refer to the length and rely on the supplier to work out the extra to get the coverage of the dished end. I can see that some people might prefer to give the exact dimensions and I think I might agree just trying to explain why T-T is used.

Your industry or country segment may be unusual in that respect. As far as I know the ASME still defines vessel sizes by OD and overall length.

I never assume that the temperature is deg C. Its simply has to be specified. More so in the oil industry it rather means Fahrenheit if not specified. There is no logic in not stating what it really is if its an engineering question.

In terms of how the vessel stands up I would be concerned about the extra loading if cladding, climate screen, insulation is added to the vessel. It might need some extra engineering. A climate screen maybe gets away with an external frame.

Exactly I mean that the whole concept of the vessel and its full height has to be taken into consideration for a screen.

You still express that the question is not really clear and T-T might be a term being used but its not alone relevant for the definition of the vessel size.

If somebody asks me I vote B.

Dry-bulb design temperature in Kuwait is considerably more than 85dF (more like 105-110, probably; my manual doesn't say). However, another thing we don't know from the OP is whether this vessel has any self-cooling provisions, such as an LNG tank might have. In that case, the climate screen might reduce the amount of bleed-off vapor.

I'll try and cover the replies in one go

I am sure that the temperature is 85C as the other units are metric but you are right dry bulb temps for Kuwait are going to be 45C / 110F.

My experience is as a process engineer so my role would be to set the design conditions and size of the vessel to do its process function.

Te design temperature is set in various ways typically Max Op + 20C. However there is a minimum threshold to reflect that equipment sits in the sun. Whilst metal vessels are not perfect absorbers ie black bodies if you assume that they absorb all the incident radiation then a temperature can be determined when the incident solar radiation equals the heat loss by convection and this is called the black body temp and 85C is a common value in the Gulf.

The design temperature as used in this context is a mechanical temperature and reflects the strength of the metal at the relevant temperature. Dry bulb temperatures are more commonly (in my experience) used in designing the capacity / size of equipment cooling towers air coolers etc

the function of the vessel has me puzzled - 230 barg is very high. The only vessels that I have used at that pressure recently have been compressor KO vessels and pig launchers / receivers. I am not sure how methane behaves at 230 barg and if the concept of liquid / vapour even applies but it would be interesting to know what is going on but yes I agree a screen would reduce incident radiation so could reduce BOG.

As the process engineer I dont do the final ASME data sheet (thats the Mech Eng job) so maybe they do overall length. As was explained to me the reason why Tan-Tan is used is that its a fixed length with no argument. Most vessels have a nozzle in the centre of the dished end so do you measure to where the end of the dish would have been? to the int on the dish where the nozzle is welded ; to the flange on the nozzle? how do you know what the nozzle stand out is? Also if the nozzle size changes and / or the stand out changes then this might change the length. Also Tan-Tan is a process function - we tend to ignore any useful function performed in the dished ends

I would also say that temperature is a factor at lower temps than 650F. I dont have the tables with me but when I looked up 150# ratings the max allowable pressure at room temp was about twice the pressure at 650F which has a big impact on wall thicknes. Whilst the metal is still structurally sound it wont hold against the design pressure at 650F if it was only designed for the pressure at room temp. At least htats my understanding of the tables.

I think he means "ΔT", but I could be wrong. I was, once, a long time ago.

I think its a She!

I also think if OP does not come back with more information then we will never be able to help.

Purpose of the "climate screen" is still unknown!

In this context, DT = design temperature. (And dp/dt is irrelevant, but it is important in other contexts.)

It would be interesting to see someone explain why that was OT. In context, it was perfectly on topic. Unfortunately, this thread is loaded with misconceptions from people who clearly have limited experience.

Now there is an OT when I see one!

Nothing I have said on this thread has been off topic. Your behavior here is amazingly uninformed and unprofessional.

Texas is not a very wet place. Quite the contrary.

Jut sayin'.

but when its wet its forking wet especially Houston and the Gulf Coast which is where the refineries are located.

My understanding for the inbreathing requirements in API 2000 are based on a violent gulf coast storm cooling a tank after its been sitting in 110F sun all day

Hello All,

To begin with, design temperature (DT) is 85 degreee celsius and design pressure (DP) is 231 bar ga. Overall length of the vessel is 13540 mm and material is SA-266 Grade 2. This is an emergency hydrogen drum (vessel in general) designed with ASME sec VIII Div 2. As the note says, it is not an external insulation as it needs to be 100mm away from vessel wall. We are in touch with our process engineers also but the details for this screen is yet to be finalized. As per our project, the ambient temperature of Kuwait is 50 degree celsius. The reason behind using one such screen is weather protection only. I am considering your suggestions to design screen keeping effects of wind in mind.

As we need to confirm details to our vendor, i am more considered about type, size, material of screen and its support clips. I will be happy if we can think about that too.

Maybe ask the vendor what he suggests in your case. There should be ample interest to talk you into one or the other solution.

Everything from metal plates to plastic sheets comes to mind for a screen.

I am always learning new stuff but I have not found any term for what you are looking for that is used in the industry. Cladding came to mind but nothing there.

Looked at below link, but nothing there either.

http://www.denvermineral.com/Pdfs/TankVesselHandbook.pdf

How about a proper paint job for weather protection. Wind with sand of course will make that useless.

I guess your best bet is to talk to the vendor or vendors out there to get details but surely you need to talk to the engineers that designed the system too.

Good luck!

Hi Rashli its good to see a response from the OP (Original Poster I think)

The problem is that we are still a lot in the dark.

The purpose of the weather screen is still a mystery.

Do any of the other vessels have such screens? If so do they explain why they have them?

If some vessels have them and some not then why is there a difference?

The differences could be due to:

Size of vessel

Function (process materials in the vessel)

With the weather is wind? rain? sand? protection the main concern?

e.g with a cold fluid a sun screen would reduce incident radiation and reduce the boil off rate. That doesn't see likely in your service.

It is also curious as to why the screen has to be so close to the vessel. 100mm is close in some usages but if it were a sunscreen then it would not have to be that close.

I feel something is being missed here in either your understanding or explanation perhaps something that is obvious to you so you have not mentioned?

Finally I will go back to an early point. If this vessel has already been fabricated then do NOT repeat do NOT just go and weld some brackets on the outside for this weather support. Any additional brackets for externals must be considered and treated at the original time of fabrication. The heat affected zone can be remediated but it is difficult at site.