HPAA Corrosion Inhibitor for Carbon Steel & Copper
HPAA — 2-hydroxyphosphonoacetic acid, CAS 23783-26-8 — is a phosphonate corrosion inhibitor whose corrosion protection for carbon steel is 5–8 times stronger than HEDP or EDTMP, making it the go-to inhibitor for low-hardness, low-alkalinity and otherwise corrosive cooling water. It resists hydrolysis, cuts iron fouling to keep heat transfer high, and works in synergy with zinc, copper and other phosphonates.
What is HPAA?
HPAA (2-hydroxyphosphonoacetic acid) is an organic phosphonic acid that combines a phosphonic group and a carboxyl group on a short carbon chain. That structure gives it high chemical stability, strong resistance to hydrolysis, and outstanding corrosion inhibition — particularly for carbon steel. It is supplied as a clear-to-amber liquid.
Why HPAA is a top corrosion inhibitor
HPAA's corrosion-inhibition efficiency is reported to be 5–8× that of HEDP and EDTMP. It performs where other inhibitors struggle — low-hardness, low-alkalinity, strongly corrosive water — and it suppresses iron dissolution and iron-oxide fouling, which keeps heat-transfer surfaces clean and efficient. It also provides useful scale inhibition, so a single product does double duty.
HPAA for carbon steel and copper alloys
For carbon steel, HPAA builds a protective film and is most effective combined with zinc salts for a synergistic corrosion program. For copper and copper alloys it is paired with a copper corrosion inhibitor such as benzotriazole (BTA) or tolyltriazole (TTA). HPAA also blends well with other phosphonates (HEDP, ATMP) and AA/AMPS dispersants.
HPAA dosage
In circulating cooling water HPAA is generally dosed at 2–15 ppm, usually as part of a zinc/phosphonate/copolymer formulation. Because it is so efficient, HPAA often allows a lower total inhibitor dose than legacy programs, especially in soft or aggressive make-up water.
HPAA vs HEDP vs ATMP (corrosion focus)
| Property | HPAA | HEDP | ATMP |
|---|---|---|---|
| Primary role | Corrosion inhibitor | Scale inhibitor | Scale inhibitor |
| Carbon-steel corrosion protection | Excellent (5–8× HEDP) | Fair | Fair |
| Best water type | Low-hardness / corrosive | General / hot | General cooling |
| Iron-fouling control | Strong | Moderate | Moderate |
| Typical partner | Zinc, BTA/TTA | Copolymers | Zinc, copolymers |
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Frequently asked questions
What is HPAA used for?
HPAA (2-hydroxyphosphonoacetic acid) is mainly used as a corrosion inhibitor for carbon steel and copper alloys in circulating cooling water, particularly in low-hardness, low-alkalinity or corrosive water. It also provides scale inhibition and reduces iron fouling.
Why is HPAA better than HEDP for corrosion?
HPAA's corrosion-inhibition efficiency is about 5–8 times that of HEDP or EDTMP, and it works well in low-hardness, corrosive water where HEDP is weaker. HEDP remains a stronger scale inhibitor, so the two are often combined.
What is the dosage of HPAA in cooling water?
HPAA is typically dosed at 2–15 ppm in circulating cooling water, usually combined with zinc salts and/or copolymers for a complete corrosion and scale program; exact dose depends on water quality and metallurgy.
Can HPAA protect copper?
HPAA protects carbon steel; for copper and copper alloys it is combined with a dedicated copper corrosion inhibitor such as benzotriazole (BTA) or tolyltriazole (TTA).
Is VCYCLETECH an HPAA manufacturer?
Yes. VCYCLETECH manufactures HPAA factory-direct in China, ISO 9001/14001/45001 certified, with a COA on every batch, free samples and OEM/ODM service. Email sales@vcycletech.com for a quotation.
About the manufacturer
VCYCLETECH is a China-based manufacturer of water treatment chemicals — antiscalants, scale & corrosion inhibitors, coagulants, flocculants, biocides, dispersants and paper chemicals — ISO 9001 / 14001 / 45001 certified, with a COA on every batch and OEM/ODM service. See our quality & certifications.
References
- Phosphonates in water treatment — Wikipedia
- Corrosion inhibitors — Wikipedia
- Cooling tower water treatment — Wikipedia
Related: HPAA product · All phosphonates · Cooling water treatment · What is an antiscalant