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We provide design, engineering and consultation for the following products:


Polyethylene & Filament Wound FRP Tank

  • 20 – 12,000-gallon polyethylene; up to 75,000-gallon FRP
  • Single, double wall, and dual containment
  • High-density Cross-link or FDA-compliant linear polyethylene
  • Closed top, open top and conical, dish or flat bottom
  • NSF- and FDA-approved
  • Up to 5-year warranty
  • Vertical storage tanks and Full Drain Outlet (FDO)
  • Free-standing horizontal leg tanks
  • Single and double wall day tanks
  • Rectangular polyethylene tanks
  • Customized Chemical pump skids

Steel & High Alloy Tanks

  • Up to 250,000 gallons
  • Atmospheric and ASME certified pressure vessels
  • NSF- and FDA-approved
  • Can build to UL, API, AWWWA, ABS, ASME, NYC, ATA, ULC standards
  • Fireguard tanks that exceed UL-2085 and UL-142 standards for storing flammable and combustible fluids
  • Flameshield tanks – dual wall steel tank with interstitial space between the inner and outer tanks that can be monitored for leakage

Support Tanks and Basins

  • IBC base container
  • Non-pressure piston bin
  • Polyethylene chemical feed stations
  • Chemical feed stations
  • Rectangular secondary containment basins
  • Cylindrical secondary containment basins
  • Chemical resistance tables
  • Polypropylene rigid storage totes
  • Custom plastic fabrication services (polypropylene, Lexan, acrylic, and many others)

Tank Accessories

  • Polyethylene tank stands
  • Can come fully insulated or insulated on site.
  • Molded in full drain outlet
  • Flange fittings/bulkhead fittings
  • 316 SS fittings/PVC self-aligning dome fittings
  • Vent assemblies/polyethylene welded connections for linear tanks
  • Fill line assemblies/anti-foam elbow
  • Seismic and wind load restraints
  • Passive restraint assemblies/sight gauge assemblies
  • Lifting lugs/reverse float level indicator
  • Fiber reinforced ladder assemblies/agitator support brackets
  • Metallic nozzles
  • Bottom outlets
  • Interstitial leak detection
  • Top discharge with foot valve
  • 21″ and 24″ manways


Not All Tanks are the Same

Assmann polyethylene tanks are rotationally molded and air-cooled, not water-cooled. They have chosen this slower process to ensure better cures for more stable parts. All cross-linked Assmann tanks consistently achieve gel tests in the high 70% to low 80% range throughout the tank, significantly higher than the ASTM minimum of 60%. This means that Assmann tanks last longer for long-term storage of harsh chemicals.

Rotationally molded tanks from your choice of virgin high-density Cross-link or FDA-compliant linear polyethylene. Either is more corrosion and chemical resistant than fiberglass, stainless, or mild steel. All double wall tanks are designed with wall thicknesses equal to or greater than that required by ASTM D-1998 standards. Since the rotational molding process uses no pressure, it will yield a stress-free tank or part.

The biggest advantage of cross-linked high-density polyethylene bulk tanks are that they are more corrosion and chemical resistant than fiberglass, HDPE, stainless, or mild steel tanks. Cross-linked polyethylene also offers excellent impact and stress cracking resistance and is the best choice for chemicals that are known to be stress cracking agents such as sodium hypochlorite.

While our tanks are available in seamless molded one-piece units from virgin high-density Cross-link polyethylene, we can also produce many products using FDA-compliant linear polyethylene for food grade applications where it is necessary.

All polyethylene is vulnerable to degradation upon long-term exposure to sunlight. This degradation is brought about by physical changes, which occur in the polyethylene as a result of exposure to the ultraviolet (UV) portion of sunlight. The temperature of exposure is also important as the higher the temperature, the more degradation will occur. Assmann offers our standard product line in a variety of colors. The way that we try and prevent UV degradation is by having our material suppliers compound an ultraviolet stabilizer into the polyethylene. This stabilizer is to help prevent UV degradation of the plastic, not the tank’s contents. Along with this Assmann’s uniform wall thickness adds extra material to the dome of the tank and helps eliminate the amount of UV breakdown that happens to the dome of the tank (the thicker the material, the longer it takes to break down).

Historically, tank manufacturers have recommended using “black” pigment in the polyethylene to help protect the chemical being stored. We do not feel that black pigment gives additional UV stability. While black pigment helps block sunlight, it also increases the amount of heat the tank gathers from the sun. The ultimate best method to prevent UV penetration into the tank is a 1″ thick coat of foam insulation with mastic coating. This insulation virtually eliminates UV rays from entering the tank, thus helping protect the tank and the chemical being stored.

Assmann Corporations Cross-link Tanks are NSF and ANSI 61 certified for chemical storage and our linear polyethylene tanks have been certified by NSF and ANSI 61 standard for potable water. NAF / ANSI 61 program is responsible for the certification of drinking water treatment chemicals and drinking water system components to ensure that these products do not contribute contaminants to drinking water.

Download the Assmann NSF and ANSI 61 Certification PFD here.

Download the High Purity Tanks Cutsheet PDF here.

Download the See-Through Manway Cover Cutsheet PDF here.


Our team is here to help you with all your chemical and industrial tank needs.

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