Vapor Recovery Piping 3

[starscreamer]

Hi there,

I am a fresh design engineer working with aluminium tanker manufacturer. My superior asked me this question regarding vapor recovery.

" Why vapor recovery pipe being installed inside the barrel of the tanker?"

Hope that somebody will help me regarding this matter.

 

[LittleInch]

Because that's where the vapour is??

Very vague question so very vague answer. If you want more input supply more details or drawing / sketch. It's very easy to upload a file but gives people much more to chew on.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[gr2vessels]

The liquid transfer from the tanker to the storage tank or viceversa generates vapour pressure differential. To prevent the collapse of the tanker or the storage tank, the vapour space between the tanker and storage tank is connected via fixed and/or flexible piping, thus equalizing the vapour pressure. This will also prevent the venting of dangerous vapours, like fuel vapour which could ignite and causing the explosion of the tanker and the storage tank. Please note that every country in the world has a dangerous goods handling code/standard which stipulates the above description as mandatory regulations.
Cheers,
gr2vessels

 

[starscreamer]

LittleInch

Thanks for replying but i find that your answer is really not matured at all. As an engineer, you should at least have some info on what you're going to talk instead of just give some random answer, and if you don't fully understand, don't be so arrogant.

As for the drawing, you should be alert that some things are not meant to be disclosed. I cannot upload the drawing because it is company policy.

anyway, cheers. really appreciate your reply.

gr2vessels

Yes, i am aware of that matter. however, what i meant to ask is why the vapor pipe are located inside the barrel. why not the designer or engineer design it so that it will be located outside the barrel?what are the design recommendation when dealing with vapor pipe. Is it not safe to put it outside because of the travelling condition? or does putting the vapor line inside will be more economic and cost effective?

p/s: the road tanker is design according to UNADR and Australian code and standard for dangerous good handling.

 

[LittleInch]

Ahmad,

You're new on this site so please learn that if you only offer a vague question with no details then you will only get a vague response. If you'd added what you put in the reply in the first place then we would have much more to go on. Don't be so touchy - you won't last long in engineering that way.

You don't necesarily have to upload full draiwngs, but some sort of sketch or information is normally very useful.

I am a little surprised your superior is asking you this question - if he doesn't know then I don't know in your company who else there is to ask as it is not something which is a general design point. I can only speculate that internal piping both reduces connections through the shell, which are more difficult than internal ones and, probably more importantly, in the event of the tanker rolling over, the external connections won't snap off and pour the tanker contents all over the ground.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[gr2vessels]

Well, in absence of better description or sketch, I assume we are talking about the vertical pipe inside the tanker which is open in the vapour space.
It is very confusing your question of why isn't the 'vapour pipe' outside the tanker. Do you mean why isn't it hanging on the side of the tanker?
The vapour pressure equalization nozzle is located for handling convenience in the bottom of the tanker, next to the filling and discharge API connection (or similar connection). Usually, the 'venting' nozzle/connection allows a flexible pipe to be connected between this nozzle and the corresponding nozzle on the storage tank.
Is this any closer to your question?
Cheers,
gr2vessels

 

[chicopee]

One obvious reason for the vapor line not being outside the tanker is the possibility of damage and the extra expenses to protect such pipe from being damaged.

 

[PieterStander]

If you do not have the answer yet;

The reason is actually very simple, it all depends on the certain country's API envelope on the tank truck, i.e. in my country the vapour connection is at the rear of the truck hence we can bring the vapour pipe out from the outside of the coaming 9roll over protection which also doubles as the vapour manifold) and let it drop down to the suitable height at the back of the tanker and not protruding from the side of the barrel.

In most other counties, the vapour connection is inside the API envelope 9between the 5th wheel/Truck cab and wheel, this means that it will make more sense from a space and safety point of view to bring the vapour pipe down from the coaming through a compartment closest to the end of the API envelope.

http://www.dlm.co.za:

Over Pressure Protection; Flow, Level & Density Measurement; Automation and Control.

http://www.metermatic.co.za:

Electronic Presets; Additive Systems.