HMDTMPA is a highly stable organic phosphonic acid scale and corrosion inhibitor, widely used in water treatment, oilfields, and textile dyeing. Its usage period depends on application conditions (temperature, pH, system type). Below are key guidelines:
1. General Usage Period
| Application | Recommended Dosing Method | Effective Duration | Replenishment Needed? |
|---|---|---|---|
| Cooling Water Systems | Continuous / Batch dosing | 7–30 days | Yes (monitor scaling) |
| Textile Dyeing | Single batch addition | 1 dyeing cycle | Fresh dose per batch |
| Oilfield Injection | Continuous injection | 15–60 days | Yes (depends on TDS) |
| Boiler Water | Continuous dosing | 30–90 days | Slow degradation |
2. Factors Affecting Stability & Duration
① Temperature
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< 60°C: Stable for months.
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60–100°C: Gradual degradation (~10% per month).
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> 100°C: Rapid breakdown (not recommended for steam boilers).
② pH Range
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Optimal: pH 6–10 (stable, effective chelation).
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< pH 4 or > pH 12: Decomposes faster.
③ Oxidizing Conditions
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Chlorine/oxidizers degrade HMDTMPA → shorter lifespan in bleach-containing systems.
④ System Contaminants
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High Fe³⁺/Ca²⁺ → Consumes HMDTMPA faster (forms complexes).
3. How to Prolong Effectiveness?
✔ Combine with polymers (e.g., PAA, HPMA) → Synergistic scale inhibition.
✔ Monitor residual phosphonate (test kits available).
✔ Avoid overdosing (excess can precipitate with Ca²⁺).
4. When to Replenish?
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Cooling water: When scaling/corrosion increases.
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Textile dyeing: Fresh dose per batch (exhausted in process).
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Oilfields: Based on water analysis (Ca²⁺, Fe²⁺ levels).
Conclusion
HMDTMPA typically remains effective for 1 week to 3 months, depending on conditions. For long-term systems, combine with stabilizers and monitor performance. Need a custom dosing plan for your setup? Let me know your water chemistry!