There are stringent
standards available for poly storage tanks made from
Polyethylene. Not every manufacturer makes tanks that
adhere to these standards, but we do. The standards are
from the American Society for Testing and Materials. They
are the worlds largest source of standards.
When it comes to plastic tanks, the
ASTM has standards that apply to the most popular storage tanks.
ASTM D 1998 is a set of standards that apply to Vertical Tanks
over 500 gallons made from Polyethylene. The standards are
for tanks produced from cross-linkable polyethyelene (XLPE) and
non cross-linkable polyethylene (HDPE). They apply to
closed top vertical tanks and to open top vertical tanks. Two plastic tanks
sitting side by side may look the same but if one is not up to
the ASTM standards, that tank may be more likely to fail.
The ASTM D 1998 standard defines
minimum wall thicknesses for polyethylene tanks based on the
height of the tank, outside diameter of the tank and the
specific gravity rating. The standard builds in a
significant safety factor by using very conservative values for
some of the resin properties.
When purchasing poly storage tanks, be
sure that you compare apples to apples. Be sure that the
tanks you select comply with the stringent standards set by ASTM