Necessity of Dip Tube in Storage Tanks

First, that isn't an image of a gas water heater.

Second... what?

kinda like heat elements....mo flame on the inside

That sounds like a good idea. One thing to watch out for, though, is any sort of pressure reversal that might siphon the tank dry via the dip tube.

Get out much?

If the cold water inlet is close to the hot water outlet, what problems might that cause with hot water delivery?

See Tornado's response.

Some type of splash/foam control is a good idea.

That would be the job of whomever is designing the tank for you.

You DO have someone knowledgeable designing the tank, don't you?

As in the hot water heater the dip tube serves a purpose. To drop the cold intake water to the bottom keeping it from mixing with the hot water at the top. I like my showers hot not tepid.

So what purpose would your dip tube serve?

in reading some of the replies..........are you simply "storing" fluid or using these as heated tanks???

Large steel storage tanks are usually built for a specific purpose and as such are built to specific standards....

http://superiortank.com/types-of-tanks/standards/

As mentioned in previous posts, the dip tube in a hot water heater has as specific purpose- to ensure correct turnover of water, and to minimize the buildup off sediment.

A storage tank is different. I have often put dip tubes into blending tanks to minimize splashing and foam generation. If that is your goal, the best option is usually a bottom tank fill, secondly a dip tube, third a partial dip tube flared to dispense a stream onto the vessel wall, and finally an open drop from the top being least preferable. Why do you think a dip tube would increase foaming??

i should have well versed my question ..but English isn't my mother language :)

I meant that inclusion of dip tube could curb the foaming Caustic produces when is allowed to free fall in a storage tanks ..especially when tank is nearly empty.

Absolutely!

Note that it requires consideration of the fill procedures as well. If the dip tube terminates slightly above the expected "empty" level, most of the air in the piping will be blown out (providing the fill rate and piping sizes have been properly correlated) before the dip tube can start "bubbling", so that there is only a bit of splashing at the beginning of the fill. My preference is usually for a 45 degree outlet on the end of the tube as well.

Of course, if the lines are blown out afterwards the dip tube then increases the foaming!

The reason for not filling the tank through a nozzle at the bottom needs to be revealed.

Has this plant been the subject of a HazOp Study yet?

Nozzles at the bottom (especially for something like caustic soda) could become plugged by carbon dioxide absorption, leading to insoluble (in the caustic soda) sodium carbonate. This is bad for business.

They can be made siphon proof by addition of a siphon breaker hole on the tube near the roof of the tank

Sir can you please elaborate this

It is a small hole near the top of the fill line to break siphon if there was a chance of flow reversal, so that the line start sucking in air, and siphon effect is killed.

If you are having a bulk tank that requires heating in a cold climate to prevent crystallization of the material (i.e. high concentrations of caustic soda), then you would also need to provide for internal circulation of the tank perhaps, or this might be done by normal thermal circulation if the tank is not too large.

<...large M.S storage tanks ..especially for Caustic (50wt%) tanks because caustic cause lot of foaming which may cause erosion-corrosion...>

According to this: Chemical Compatibility Database from Cole-Parmer United Kingdom (coleparmer.co.uk), these two materials are incompatible with each other, and the effect of <...foaming...> is therefore irrelevant.