
Handling phosphoric acid – especially wet-process phosphoric acid (WPA) – is one of the most demanding pump applications in the chemical industry. The fluid contains sulfuric acid, hydrofluoric acid, gypsum solids, and high chloride levels. Standard stainless steels (304, 316L) suffer rapid pitting and stress corrosion cracking. Even Duplex 2205 may show limited life.
CD4MCu (ASTM A995 Grade 4A / A890 Grade 4A) is a dupleks keluli tahan karat specifically developed for severe corrosive/abrasive service. When combined with Hunan Durafort’s Pam turbin menegak LC design, it becomes the ideal solution for phosphoric acid transfer, reactor circulation, filter feed, dan pond return applications.
✅ Hunan Durafort Pumps – A professional pump manufacturer in China – produces CD4MCu vertical turbine pumps, along with other high‑alloy materials (Super Duplex 2507, 904L, Titanium, etc.).
Why CD4MCu for Phosphoric Acid Service?
CD4MCu offers a unique combination of properties that make it outperform austenitic and many duplex grades in wet‑process phosphoric acid:
| Harta | CD4MCu | 316L Stainless | Duplex 2205 |
|---|---|---|---|
| PREN | ~35–38 | ~25 | ~35 |
| Kekuatan hasil | ≥ 550 MPa | ~210 MPa | ~450 MPa |
| Erosion Resistance | Excellent (harder) | Poor | Baik |
| Resistance to Galling | Sangat tinggi | rendah | Sedang |
| Performance in WPA (50‑80°C) | Excellent (2+ years) | <6 months failure | 12‑18 months |
Key advantages in phosphoric acid:
- Outstanding resistance to phosphoric + sulfuric acid mixtures (common in WPA)
- High hardness (~280 HB) resists solid abrasion from gypsum (CaSO₄·2H₂O)
- Excellent resistance to pitting and crevice corrosion in chloride‑containing acidic brines
- Low galling tendency – critical for vertical turbine pump line shafts and bearings

Technical Data – LC Vertical Turbine Pump (CD4MCu Construction)
Hunan Durafort's Pam turbin menegak siri LC dihasilkan di CD4MCu is designed for continuous duty in phosphoric acid plants. Below are the standard technical parameters:
| Parameter | Nilai |
|---|---|
| Julat Aliran | 50 – 8,400 m³/j |
| Julat Utama | 15 – 150 m |
| Pilihan Kelajuan | 980 / 1480 / 2970 rpm |
| Suhu maksima | ~150°C (suitable for hot WPA up to 100°C) |
| Wetted Materials | CD4MCu, Duplex 2205, Super Duplex 2507, 904L, Titanium (customizable) |
| Shaft Material | CD4MCu or stainless steel with CD4MCu sleeve |
| Bearings | Silicon carbide or PTFE‑lined for acid service |
📌 Other alloys available: Carbon steel, ductile iron, SS304, SS316L, and higher grades.
Key Applications – CD4MCu Vertical Turbine Pumps in Phosphoric Acid Production
1. Wet‑Process Phosphoric Acid (WPA) Plants
In the di‑hydrate or hemi‑hydrate process, phosphoric acid is produced by reacting phosphate rock with sulfuric acid. The resulting slurry contains 25‑35% P₂O₅, 2‑5% H₂SO₄, and gypsum solids. CD4MCu vertical turbine pumps are used for:
- Attack tank circulation
- Filter feed (to rotary drum filters)
- Weak acid transfer (to evaporators)
- Pond water return (recycling dilute acid)
2. Phosphoric Acid Concentration & Purification
After filtration, weak acid (~28% P₂O₅) is concentrated to 54% or higher in evaporators. CD4MCu handles both the hot concentrated acid and the corrosive vapors.
3. Fertilizer Production (MAP, DAP, NPK)
Mono‑ammonium phosphate (MAP) and di‑ammonium phosphate (DAP) production involves reacting phosphoric acid with ammonia. CD4MCu pumps resist the aggressive intermediate slurries and finished product solutions.
4. Phosphoric Acid Storage & Loading
Large vertical turbine pumps are often installed in acid storage ponds or tanks to transfer acid to rail/truck loading stations. CD4MCu provides long life even when pumping acid containing settled solids.
5. Industrial & Mining By‑product Handling
Phosphogypsum ponds, stack water return, and scrubber systems all benefit from CD4MCu’s combination of acid corrosion and abrasion resistance.
Advantages of Choosing Hunan Durafort Pumps for Your Phosphoric Acid Plant
Sebagai pengilang pam profesional di China, Hunan Durafort Pumps offers:
✅ Material traceability – 100% positive material identification (PMI) and EN 10204 3.1 certificates
✅ Precision cast CD4MCu components – Impellers, bowls, and suction bells with smooth surface finish to reduce erosion
✅ Customized designs – Any column length, flange rating (PN10/16/25/40), or shaft sealing arrangement
✅ Masa penghantaran yang singkat – Typically 8‑12 weeks for CD4MCu pumps (much faster than European or US competitors)
✅ Sokongan global – Spare parts available for all models: XSP split case, LC turbine pump, HD mixed flow pump, Aliran paksi ZLB pump.
🔧 We also manufacture vertical turbine pumps in Super Duplex 2507, 904L, CD4MCu, Titanium, dan Hastelloy – let our engineers recommend the best alloy for your specific acid concentration and temperature.
Performance Comparison – CD4MCu vs. Other Alloys in Phosphoric Acid
| Bahan | Typical Life in WPA (50‑80°C, 30% P₂O₅ + 3% H₂SO₄ + 5% solids) | Cost Factor | Recommendation |
|---|---|---|---|
| Cast Iron / Carbon Steel | <1 month (rapid corrosion) | 1.0 | Not suitable |
| SS316L | 3‑6 months (pitting, erosion) | 1.5 | Avoid |
| Duplex 2205 | 12‑18 months (good, but may pit in high Cl‑) | 2.0 | Acceptable for low Cl‑ |
| CD4MCu | 24‑36+ months | 2.5 | Preferred |
| Super Duplex 2507 | 30‑48 months | 3.0 | Excellent (higher cost) |
| Titanium Gr.12 | 60+ months | 8.0 | Overkill for most WPA |
Kesimpulan: For most phosphoric acid duties (WPA, filter feed, pond return), CD4MCu vertical turbine pumps offer the best cost‑performance balance.
Soalan Lazim (FAQ)
Q1: Is CD4MCu suitable for hot concentrated phosphoric acid (>80°C, >50% P₂O₅)?
A: Yes. CD4MCu performs well up to ~100°C in concentrated phosphoric acid, provided chlorides are below 1000 ppm. For higher temperatures or aggressive chloride levels, Super Duplex 2507 or Titanium may be recommended.
Q2: Can your CD4MCu pump handle gypsum solids (abrasion)?
A: Absolutely. CD4MCu’s high hardness (280 HB) and work‑hardening properties give it excellent erosion resistance. For very high solids (>10% by weight), we can supply hardened shaft sleeves and replaceable wear rings.
Q3: Do you offer NACE MR0175 certification for CD4MCu?
A: CD4MCu is not typically NACE certified for sour service. However, we can provide material test reports and hardness tests if required for specific environments.
Q4: What about replacement parts for existing CD4MCu pumps?
A: Hunan Durafort supplies fully interchangeable spares (impellers, bowls, shafts, bearings) for most major brands of vertical turbine pumps. Just send your drawing or sample.
Q5: How do I size a CD4MCu vertical turbine pump for my phosphoric acid application?
A: Contact our technical team with: required flow (m³/h), total head (m), acid concentration (% P₂O₅), temperature (°C), chloride content (ppm), and solids percentage. We will provide a detailed quotation within 48 hours.


Contact Hunan Durafort Pumps – Your CD4MCu Pump Expert
Don’t risk unplanned downtime in your phosphoric acid plant. Upgrade to CD4MCu vertical turbine pumps daripada Hunan Durafort Pumps – combining Chinese manufacturing efficiency with world‑class material science.
📧 E-mel: sales@deyangforge.com
🌐 Laman web: www.deyangforge.com
🏭 Lokasi kilang: Changsha, Hunan, China – ISO 9001:2015 certified
Request your free corrosion guide for phosphoric acid pump materials today!


















