B502-78: AWWA Sodium Polyphosphate, Glassy (Sodium Hexametaphosphate) (PDF)
SKU: STB_0006815-PDF
Sodium hexametaphosphate is a manufactured product obtained by combining comparatively pure chemicals, soda ash (Na2C03) or caustic soda (NaOH), with phosphoric acid. The resulting product is consistent in quality and content, but each manufacturer may produce it in several different physical forms.
Description
The First Edition of this standard was approved June 1967 and revised January 1978. This standard covers sodium hexametaphosphate for use in water treatment. The application of the chemical includes corrosion control, scale prevention, iron and manganese stabilization and removal of hardness. Included is a brief history of the standard and a discussion of the chemical. The following sections are included: general information, affidavit for compliance, basis for rejection, material specifications, impurities, physical and chemical requirements, sampling, packing and shipping, marking, and various testing methods for size, solubility, test procedure for phosphorous pentoxide, and sodium oxide content.