Engineered ASTM D1998 Polyethylene Upright Storage Tanks

This specification covers flat-bottom, upright, cylindrical tanks molded in one-piece seamless construction by rotational molding. The tanks are molded from polyethylene for above ground, vertical installation and are capable of containing aggressive chemicals at atmospheric pressure. This specification does not cover the design of vessels intended for use at pressures other than atmospheric pressure. Furthermore, this specification does not cover the design of portable tanks and is not for vessels intended for use with liquids heated above their flash points in continuous service. Special design considerations not covered in this specification shall be given to vessels subject to superimposed mechanical forces, such as seismic forces, wind load or agitation; to vessels subject to service above specified temperature; and vessels subject to specified superimposed pressure of water. Low-temperature impact test shall be performed on rotational-molded polyethylene tanks. The test method is used on tanks molded from both the crosslinked and non-crosslinked polyethylenes. Dart drop impact test shall be performed to determine the quality of the tank. O-xylene-insoluble fraction or gel test shall be performed on crosslinked polyethylene. Visual inspection and water test shall also be performed on the samples.