Air Eliminator / Air Release Vent / Air Release Valve for Petroleum Pipeline

[Babyblue99]

Hello, I am trying to design & choose an Air eliminator / Air Release Valve for Petroleum Pipeline from Fuel Terminal to Oil Vessel.
I have several questions about this:
1. Is there any regulation that allows me to use an Air Release Valve for this application?
2. If its possible, how to determine the dimension of Air Release Valve of 12-inch Petroleum Pipeline?

 

[1503-44]

How is it that you have air in a petroleum pipeline, or do you mean petroleum vapor, not air?



--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[LittleInch]

Assuming this is "petroleum" - rather vague description, any vent needs to be to a "safe location", common vent or flare. Normally releases like this are not allowed for operational purposes and create a hazard which doesn't exist if you don't have one.

Why do you want to do this? normally any vapour pocket sin the lines or hoses are swept out of the pipe or hose and dealt with by the vessel. They need to allow for vapour to be released as the tanks fill up. If its the other way around, the tanks will normally handle any vapour in the lines.

If you really really want to do this then the sizing is up to you. All depends on how fast you want to release your volume, but I would suspect you would want 1 1/2" or 2".

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

 

[Babyblue99]

Dear 1503-44 & LittleInch

I think its an air, and it is caused by blowing activity in order to ensure that the line is on full pack condition before entering the Flow Meter as Custody between Fuel Terminal & Ship.

I want to do this because i've seen in another terminal & internet that before entering Flow Meter there is a Strainer with an Air Eliminator (Automatic Air Vent) located above the strainer, and i want to do the same thing to make sure the Flow Meter as Custody Transfer Measurement System is not "Changed" by Air and only "Changed" when the oil is passing by.

That's why i wanted to ask anyone in this forum for some regulation that regulated the application of Automatic Air Vent.

Thank You.

 

[shvet]

@Bbabyblue99
You are going to release an explodable&flammable&toxic mixture of air and petroleum vapors directly to atmosphere of a process site at uncontrollable conditions. Correct?

 

[1503-44]

You should not have any necessity to do that. If there is any air in the line, you should find its source and eliminate the possibility of air entry into the system. If air continues to be a problem, it needs to be trapped in a seperator, then vented from the separator to a proper vent to flare system. And the same, if it is hydrocarbon vapors, except those would typically be trapped in a seperator, then diverted to a gas pipeline, or vapor collection system.

If it is small quantities of gas that cannot be eliminated, then an air eliminator system could be used, but that is quite different from a typical air elimination valve. This link shows such a system. Pkease note that the manufacturer says themselves that it might be more economical to eliminate the source of air entry into the system.

http://www.petroproductos.com/uploads/6/4/4/2/64423277/dsairelim_r05.pdf

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[LittleInch]

"Regulation" sounds like the law. That will vary by where you are.

Mist countries have regulations which govern releases of hazardous material into the atmosphere, especially where it can affect humans.

You need to find those regulations in the place where this development is.

Getting air into a system which is then metered is a bad move.

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

 

[Babyblue99]

Dear Shvet,
I think it is not fully uncontrollable conditions, what i trying to release is air bubbles that can affect the reading accuracy of Flowmeter as Custody Transfer Measurement System. The condition is controllable, including the exclusive remote area & several safety condition like prohibition sign to bring lighter, etc.

Dear 1503-44,
Thank you so much for your suggestion, i appreciate it.
But i have several question about this, i found that there is no significant differences between the mechanical work (Ball Floating System) from the product you suggested and typical air elimination valve.
So can i just use typical Air Elimination Valve with the similar mechanical work?

 

[Babyblue99]

Dear LittleInch,

Thank you so much, I think there are several possibility source of trapped air bubbles in system i.e : cavitation of Pumps,and trapped air/vapor in accesories like elbow.
What i really meant "Regulation" here is International Standard like API, or ASME, or etc that rules the venting system / air eliminator of oil pipe.

I've seen Fuel Terminal where there is Air Eliminator located above Strainer in several points (before pumps, before flowmeters), and the fuel terminal is running for +-20 years without any significant issues with this system.
But when i do research, i haven't find the standard about this air eliminator, that's why i asking for suggestions in this forum.

 

[LittleInch]

AFAIK, there is no such standard on this as it is an operational issue. Equally the item in question is not something which AFAIK, there is any standard for, only vendor specifications or company specifications / datasheets.

Normally in liquid hydrocarbon systems you flow at a velocity which sweeps out any air (>1m/sec) and then maintain the pipes full of liquid.

Sometimes you see a coalescer or filter which has an air vent but this is either connected to the vent or flare line or operated manually very slowly and connected to a local vent 3m high.

What type of custody transfer meter?

Ultrasonic ones can be disrupted by bubbles, but this is usually when measuring very volatile fluids close to their vapour pressure.

Are you trying to solve a problem which exists or just thinking one up?

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

 

[shvet]

@Babyblue99
1/ Seems like it is "partially uncontrollable conditions" (c) of air+vapors release. Correct? If it is considered as "partially uncontrollable" then should such design be treated as "deliberately unsafe"? Seems you are in a gray zone of ethics.
2/ Crude (?) oil should not be treated as a clean fluid like a potable water is (where such air vents are widelly used) and therefore internals of such air trap auto valve will be prone to clogging and/or corrosion followed by a failure or an uncontrolled leak of liquid. Depending on actual pressure inside consequences might be tremendous. How are you planning to check a such trap is still stand-by or had failed?

Why do you believe these air bubbles are actually entrained air, not boiled components like propane or similar?
Is this design subject to HAZOP?

A common manually operated gate valve is safer and more robust&controllable. A small gas pocket is usually used for entrained air trapping and accumulation. To detect gas accumulation such trap is equipped with a built-in level sensor or a level gauge. Such design does require some attention and intervention from operating personnel but are you sure such operation like gas trapping definetly requires auto mode?

 

[georgeverghese]

If you go with the device @1503 suggested, you can ask the vendor if you can connect the gas release exhaust to the plant vent header. You should quote what is the max expected operating pressure (which should include any emergency vent release) in this vent header. At the least, it should be able to withstand a backpressure of 50psig in the event of any flashbacks in the vent header.

 

[shvet]

If you go with the device @1503 suggested

http://www.petroproductos.com/uploads/6/4/4/2/6442...

The link does not work

 

[1503-44]

Yes, today that link is broken. But do not fear.
Fortunately I downloaded it. Attached below.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."