Our Process

Why Assmann?

Assmann keeps quality first and failure far out of mind. Know that your tanks were built the right way – even if that’s not the easiest way.

No Cutting Corners

Part of what makes our process so unique is that we do not “shield” the outside of our tank molds. In a competitive marketplace it has become a common practice to wrap and weld layers of sheet metal (shielding) around the outside of the mold to reduce heat transfer.

Cross-Linking to a High Degree

We have separate chambers using only very high volume air movement to assure a gradual cooling of the mold and the part inside. This allows the cross-linking process still taking place upon exiting the oven chamber to complete throughout the entire tank wall.

Rotational Molding

Our unique and efficient large ovens, which rotate end-over-end, receive convection heat from an adjacent stationary furnace. The oven shape and foil design create optimum airflow and uniform heat to set the first stage for the highest quality parts possible.


ISO 9001:2015 Certification

Assmann is the first and only polyethylene tank manufacturer to achieve ISO 9001 certification – a high bar we have to continually maintain. Our products undergo ultrasonic thickness, gel, and impact testing at our in-house expert laboratory.

This means that Assmann tanks are designed and manufactured under strict quality control standards. Each tank we manufacture has its own quality control and routing card that links the product back to date of manufacture, raw material lot numbers, and processing times. We believe that the more effort we put into a flawless production system, the better quality product we can offer to our clients.

NSF Certification

NSF is an independent testing company that requires Assmann Corporation of America to comply with strict standards. These standards require extensive product testing and material analysis. NSF undertakes a complete evaluation of our product development before we can meet their certification.

Assmann Warranty

We Stand by Our Products

Assmann warrants our tanks to be free from defects in workmanship and materials, under normal use and service, to the original purchaser from the date of shipment from our factory.

Looking for a tank that will last?