Disodium Phosphate (Na2HPO4, CAS 7558-79-4) is a white, water-soluble salt that forms mildly alkaline solutions (pH about 9). It is used as an emulsifier and buffer in processed cheese and foods, in boiler and cooling water treatment, detergents, textile processing and pharmaceutical buffers. Disodium phosphate solutions are not very corrosive, but food-grade service needs food-contact tank materials. Use the compatibility ratings to choose the right tank resin, fittings and gaskets.
HDPE is the most economical tank material for Disodium Phosphate, rated Excellent. Polypropylene and PVDF (Kynar®) are also rated Good or better. Avoid Buna-N gaskets.
How Disodium Phosphate works with the plastics used to make our storage tanks.
| Material | Rating |
|---|---|
| HDPE | |
| Polypropylene | |
| Nylon | |
| PVDF (Kynar®) |
How Disodium Phosphate works with the plastics used for tank fittings.
| Material | Rating |
|---|---|
| HDPE | |
| PVC | |
| CPVC | |
| Polypropylene | |
| PVDF |
How Disodium Phosphate works with gasket and O-ring materials.
| Material | Rating |
|---|---|
| Buna-N | |
| EPDM | |
| Viton® |
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