Full Drain Outlet

Full Drain Outlet Tank

Assmann Corporation of America offers a full drain outlet assembly (FDO). This outlet provides the ability to fully drain your tank without the need for mechanically installed nozzles.

Assmann Patented Molded In Full Drain Outlet – Patent No. US 8,348,090 B2 & Patented Modular Polyethylene Tank Stand – Patent No. US 8,814,110 B2.

Why buy a drainage tank?

Unique about the FDO assembly is the fully replaceable polyethylene flange adapter. This provides the ability to replace the flange in the event of chemical or mechanical damage without having to replace the entire vessel.

— Molded in metallic insert
— Available in 316 stainless steel, titanium, and hastelloy c-276
— Available in most tank sizes

Modular Tank Stand

These stands elevate the polyethylene drank tank 12″ from grade. This provides the ability to fully drain the tank without the installation of expensive concrete pads. The tank can be drained and the stand is easily disassembled to allow the tank to be relocated to a different site. This stand is 100% chemical resistant and is suitable for all corrosive environments. Assmann tested this stand to over 300,000 lbs. of crush force.

— 100% chemical resistant
— Lightweight and modular
— Can be installed on any flat surface


Curious about Assmann storage solutions? Listed below are the most common questions about our Full Drain Outlet (FDO) Storage Tanks. If you have additional questions about your next polyethylene storage tank, contact our experts.

What is the recommended pad height and material?

We recommend a minimum pad height of 8” for use with our FDO tanks. Contact us for detailed drawings for installation. With the right facility conditions, we offer a modular polyethylene tank pad installation to reduce costs.

Will my tank have maximum drainage?

Assmann Full Drain Outlet (FDO) connection is installed flush to the tank bottom, designed to give maximum drainage on a vertical flat-bottom storage tank. You could have a minimum heel of liquid left in the tank due to the tank being flat-bottomed (not sloped).

Do I need to drain completely before I fill with a new product?

All customers use our tanks differently; it is common to empty your tank to a minimum safe reorder point before refilling your tank. The main benefit of using an FDO tank is that you are drawing the liquid from a low point on the tank. This can also be accomplished by using a sidewall connection with a siphon drain.

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