Tank Nozzle Codes/Standards

[302Hugo]

Good day,

I've been asked by operations to review a tank nozzle we have on one of our 90,000 bbl tanks. I have zero experience with tanks. They would like to attach a transfer pump to an existing 8" nozzle. We are unsure of what the inside of the nozzle looks like (they are currently emptying the tank). The transfer pump will be used to empty the tank and the pump will be bypassed to flow the other way and fill the tank.

I've been asked to review how low we can go with an internal spout to the tank floor. A few things that pop into my head are:

1) It doesn't matter how low with a spout you go, it all depends on the pump NPSHr, correct?....however they may hook another pump to the piping for the heal, so the down spout still may be required.
2) I can only assume having a down spout isn't good if they are looking to use it to fill the tank as well. It would cause erosion on the bottom of the tank.

So I guess what I am looking for is if someone can provide me with a list of the codes and standards for tank nozzles and piping within the tank (I'm gonna look myself, but hopefully this will speed up the process). Pressure wise I assume there isn't much to the internal piping (I assume no pressure testing would be required since it only has tank head) but I wonder about forces due to when they are filling the tank.

I guess anything that can help me out would be appreciated.

 

[MJCronin]

It sounds to me like you are looking for a standard tank detail, but you lack the "grey beards" in the corner of your organization to help you out

When a new tank is designed, a special nozzle/sump arrangement is used for filling/emptying the tank.

The major oil companies (and some of the tank people) have these nozzles drawn as standard fabrication details.

Since we don't know what exactly you are pumping, the specific liquid would also affect your choice of nozzle.

Any chance you could review the details of another similar tank ?

Or, as is most often the case, have all tank fabrication drawings been discarded when the facility recently changed hands....

 

[JStephen]

Tank nozzles are included under API-650 for new tanks, or under API-653 if being modified on an existing tank. However, these standards address fabrication details, welding, etc., but not flow-related concerns.

Erosion isn't normally considered in the design. If problems were anticipated, you could install a wear plate on the tank bottom when the ell is added.

Forces due to liquid movement are not usually significant on a nozzle design, and would not normally be considered in the design of a nozzle. Note also that flow rates are limited to reduce static build-up in the product, which helps reduce such effects.

 

[Duwe6]

For 'clean' fluids, try 1/2 to 2 pipe diameters off the floor for a suction [only] nozz. For fluids with solids, stay at least 1-diameter above the floor.

For a discharge nozzle, use 1.5 to 4 pipe diameters off the floor and install a circular "wear pad" with a diameter of [pipe diameter] * [number of pipe diameters the nozz is above the floor]. Use a plate approximatly the same thickness of the floor. 0.25-inches thick is what I usually specify.

 

[stanier]

Petroleum Tank Storage Principles by Ivan Marks ISBN 0-87814-238-X may be available from a library or Amazon.

"Sharing knowledge is the way to immortality"
His Holiness the Dalai Lama.

http://waterhammer.hopout.com.au/

 

[MJCronin]

stanier.....

Are you sure about that book title and author ?

I can find nothing similar in the internet...