Can You Store Sulfuric Acid in a Poly Tank?
Yes, with a named acid tank and containment.
By James Riggins, Lead Engineer, Liberty Chemical & Equipment Supply, Inc.
Yes, with conditions. Use a manufacturer's named sulfuric acid tank, never a generic catalog tank, and add secondary containment. At 93-98% the vendors disagree: Poly Processing says its XLPE tanks are fine, ProTank says XLPE fails within six months at 98%, and carbon steel is the standard bulk-storage material.
Sulfuric acid: tank spec points
| Point | What the manufacturer documents | Source |
|---|---|---|
| Named product | Snyder's sulfuric acid resin #880046 (linear HDLPE), Poly Processing XLPE with OR-1000 antioxidant inside its 11,000-gallon and 15-foot limit, or Houston PolyTank extrusion-wound walls built to DVS 2205. | Rule: tank material by concentration |
| Containment | Poly Processing states a containment tank is required with sulfuric acid in all applications. It is the only chemistry in its guidance with an unconditional mandate. | Rule: secondary containment |
| 93-98% band | Carbon steel passivates in this band and is the standard bulk-storage material. FRP tops out around 80%. | Rule: tank material by concentration |
| Pumps and valves | Tank material and pump or valve material follow different rules. Do not carry the tank answer over to the wetted parts. | Rule: tank material by concentration |
Where manufacturers disagree
Poly Processing's own compatibility table lists sulfuric acid as XLPE-compatible up to 98% with no service-life caveat. ProTank's published literature says XLPE fails within six months at 98%. The conflict is narrower than it looks: ProTank's objection is to cross-linked XLPE specifically, and Snyder's #880046 resin is linear HDLPE, a different polymer. Confirm service life in writing at your exact concentration before specifying.
Frequently Asked Questions
Is a polyethylene tank safe for 98% sulfuric acid?
Only a manufacturer's named concentrated-acid product, and the vendors disagree on XLPE at 98%. Carbon steel is the standard bulk material at 93-98%. Get a service-life statement at your concentration.
Does a sulfuric acid tank need secondary containment?
Poly Processing's guidance says a containment tank is required with sulfuric acid in all applications, either a double-wall design or a separate containment.
Can the same material be used for the tank and the pump?
No. Tank storage and pump or valve service are governed by different mechanisms, so choose each from its own rule.
Related
Other chemicals
Tanks by material and shape:HDPE / polyethylene tanks · Polypropylene tanks · FRP (fiberglass) tanks · Vertical tanks · Cone bottom tanks · Flat bottom tanks · Horizontal tanks · Rectangular tanks · Double-wall tanks
Send James your spec
Fluid, concentration, temperature, flow or volume, and where it goes. James replies with a real answer, not a catalog page.
Reviewed by James Riggins, 30+ years specifying water and chemical process equipment · Updated