Phosphoric acid transfer through SS 304 L pipeline
Phosphoric acid transfer through SS 304 L pipeline
(OP)
Dear Sirs,
We want to transfer phosphoric acid (70 to 80% strength) through 12" dia stainless steel SS 304L grade pipeline (5km long)@450 tons/hour at 4 to 5 bar pressure.There will be such two transfers of about 2000 tons parcels each in a month.This pipeline will be immediately pigged with suitable pig & washed with water after each transfer is over.I would like to know the compatibility of the pipeline grade with the product & any adverse effect,corossion in the line,effect on pipeline life if any.
Thanks,
dkb
We want to transfer phosphoric acid (70 to 80% strength) through 12" dia stainless steel SS 304L grade pipeline (5km long)@450 tons/hour at 4 to 5 bar pressure.There will be such two transfers of about 2000 tons parcels each in a month.This pipeline will be immediately pigged with suitable pig & washed with water after each transfer is over.I would like to know the compatibility of the pipeline grade with the product & any adverse effect,corossion in the line,effect on pipeline life if any.
Thanks,
dkb





RE: Phosphoric acid transfer through SS 304 L pipeline
Make sure your rinsing water is very low in Cl-you'll probably have concentration of whatever's in the water.
RE: Phosphoric acid transfer through SS 304 L pipeline
RE: Phosphoric acid transfer through SS 304 L pipeline
Due to the limited use, the main corrosion problem would be residue left after rinsing. As mcguire said, phosphoric acid leaves the SS in a non-passive state. Concentrated phosphoric acid is syrupy and difficult to rinse. I recommend using warm water (120-140oF), and if feasible, following that with a 5-10% nitric acid solution (for passivation) and additional rinsing. This is similar to the procedure we use following electropolishing of SS. You can store and re-use the nitric solution several times.
RE: Phosphoric acid transfer through SS 304 L pipeline