Why It Matters
Residual feedwater hardness deposits CaCO3/CaSO4 and silica on boiler tubes, insulating them and risking overheating. Design uses a phosphonate plus a polymer dispersant and chelants to sequester hardness as soluble complexes
Solution Approach
Residual feedwater hardness deposits CaCO3/CaSO4 and silica on boiler tubes, insulating them and risking overheating. Design uses a phosphonate plus a polymer dispersant and chelants to sequester hardness as soluble complexes RawSource supplies the base chemicals that go into these programs. We can help with product selection, grade matching, and sourcing from multiple origins for supply security.
Typical Treatment Workflow
1
System Assessment
Characterize operating conditions—fluid composition, temperature, pressure, flow rates—and benchmark current treatment performance.
2
Chemistry Selection
Match base chemicals to your operating envelope. Factor in compatibility with existing programs, regulatory constraints, and downstream impacts.
3
Dosage & Delivery
Determine optimal treat rates through jar testing or field trials. Configure packaging (drums, totes, ISO tanks) to match consumption and storage logistics.
4
Monitoring & Adjustment
Track KPIs—coupon rates, residuals, separator performance, water quality. Adjust chemistry and dosage as conditions change.
Recommended Chemistries (5)
Hydroxyethylidene Diphosphonic Acid
CAS 2809-21-4
Phosphate Esters & Derivatives
Primary CaCO3 scale inhibitor
HEDP threshold-inhibits CaCO3/CaSO4 and is thermally stable enough for low/medium-pressure boiler service, keeping hardness from nucleating on tubes
Melting Point: 198-199 Boiling Point: 578.8 Solubility: 1.15e+01 g/L
Full Details
Polyacrylic Acid Sodium (PAAS)
CAS 9003-04-7
Polymers & Resins
Conditioning
Polyacrylate disperses precipitated hardness and iron oxide as a mobile sludge that leaves with blowdown rather than baking onto the tube
Full Details
Sodium Polyaspartate (PASP)
CAS 55719-33-0
Acids & Salts
pH Adjustment
Biodegradable polyaspartate inhibits and disperses CaCO3/CaSO4/silica scale; a greener dispersant option. (Spine tags pH Adjustment; chemistry is scale inhibition.)
Full Details
Ethylenediaminetetraacetic Acid
CAS 60-00-4
Amines & Amides
Broad-spectrum chelant
EDTA forms soluble 1:1 chelates with Ca2+/Mg2+/Fe, dissolving residual hardness so it cannot precipitate on heat-transfer surfaces
Melting Point: 237 °C Density: 0.86 at 20 °C Solubility: 1000000 mg/L at 25 °C
Full Details
DTPA (Diethylenetriaminepentaacetic Acid)
CAS 67-43-6
Amines & Amides
High-performance chelant for iron
Higher-denticity chelant holds iron and hardness through higher temperatures than EDTA, backstopping the program at elevated boiler pressure
Physical Description: White to off-white solid Boiling Point: Decomposes Melting Point: 219-220 ºC
Full Details
Related Product Families
● Available
Phosphonate Scale Inhibitors
HEDP, ATMP, DTPMPA, and specialty phosphonates for calcium carbonate, sulfate, and silica scale prevention
Scale InhibitionChelation
5 chemistries
View family
● Available
Chelants & Sequestrants
EDTA, DTPA, and citric acid for hardness sequestration and iron control
ChelationSequestration
3 chemistries
View family