→ Scaling
Mineral deposition
CaCO₃, CaSO₄, silica. Tells: rising approach temp, dropping U-value, white crusts at fill and tube ends. Layer: chemistry. Fix: LSI recalc, dispersant dose, pH trim, lower COC.
← Knowledge Library
→ System 01 / Cooling Water
The unsung backbone of every plant.
Power, refining, petrochemicals, LNG — every continuous plant rejects waste heat through one of these. Click any node to open it up.
→ Reference / Performance benchmarks
What "good" looks like.
Typical operating envelopes for a freshwater open-recirculating system. Sea-water and closed-loop systems shift these targets — these are the ones I trend daily.
Indicator
Typical range
Why it matters
Approach temperature
3 – 5 °C
Tower outlet vs ambient wet-bulb. Drift up = fill fouling, fan trouble, or distribution off.
Range (ΔT)
8 – 11 °C
Heat load divided by recirc flow. Drops when a pump trips or a major exchanger goes offline.
Cycles of Concentration
4 – 6
Blowdown ÷ make-up conductivity. Higher = less water + chem cost, but scale risk climbs hard above 7.
pH
7.0 – 9.0
Out of band = either corrosion (low) or scale (high). Tied to LSI calc.
Free chlorine residual
0.2 – 0.5 ppm
Microbial control. Below 0.1 = biofilm window open. ORP 550–650 mV is the proxy in practice.
Langelier Saturation Index
0 to +1
+1 → CaCO₃ wants to drop out. Dispersant + acid trim handles it.
Fouling factor (Rf)
0.0001 – 0.0005 m²·K/W
Trend per exchanger. Slope tells you when the next chem clean falls due.
Drift loss
< 0.005 % of recirc
Modern eliminators meet it. Damaged eliminators throw aerosols → Legionella exposure window.
Microbial count
< 10⁴ CFU/ml
Total plate count. Spikes precede biofilm visible on heat exchanger tubes by weeks.
Chloride
< 300 ppm (304 SS)
Stainless pitting threshold. Sea-water cooling needs duplex / super-duplex or titanium.
→ Reference / Failure modes
Where it goes wrong.
Six failure families. Each has a tell, a layer to investigate first, and a default intervention. Discipline is to test the cheap hypothesis before the loud one.
→ Corrosion
Metal loss
General, pitting, MIC, galvanic. Tells: rising iron + copper in water, tube leaks, corrosion coupons > 3 mpy CS or 0.2 mpy admiralty. Layer: chemistry first, then metallurgy. Fix: inhibitor residual, pH, chloride trend.
→ Biofouling
Biofilm and Legionella
Slime layers insulate tubes and harbour Legionella. Tells: ORP drop, chlorine demand spike, microbial counts up. Layer: chemistry + housekeeping. Fix: rotate non-oxidising biocide, biofilm survey, basin clean.
→ Mechanical
Pumps, fans, drives
Cavitation, bearing wear, seal leaks, fan blade pitch drift, gearbox noise. Tells: vibration, bearing temps, motor amps. Layer: rotating equipment. Fix: alignment, balance, lubrication audit, seal flush plan review.
→ Process
Tube leaks & cross-contamination
Hydrocarbon or process side leaking into CW. Tells: hydrocarbon-in-water alarm at the return header, conductivity spike, oily film on basin. Layer: HX integrity. Fix: isolate, hydrotest, plug or retube; investigate metallurgy fit.
→ Drift & loss
Damaged eliminators, plume
Aerosols escape the tower. Tells: visible plume drop, white deposits on nearby equipment, chloride creep on adjacent SS. Layer: tower internals. Fix: drift eliminator inspection, replace damaged sections, audit fan operation.
→ Reference / Global ecosystem
Who builds what.
The names that show up on most major projects. Not exhaustive — these are the ones you will run into in tender packs and OEM nameplates.
→ Cooling towers
- SPX (Marley)
- Baltimore Aircoil (BAC)
- EVAPCO
- Hamon
- GEA
- Brentwood (fill & eliminators)
→ Water-treatment chemicals
- Nalco (Ecolab)
- Veolia Water Technologies
- Solenis
- Kurita
- ChemTreat
- Buckman
→ Pumps
- Sulzer
- Flowserve
- KSB
- Goulds (ITT)
- Grundfos
- Ebara
→ Heat exchangers
- Alfa Laval
- Kelvion
- API Heat Transfer
- Tranter
- SPX Heat Transfer
- Sondex
→ Filtration
- Eaton
- Amiad
- Forsta
- Lakos
- Hayward
→ Instrumentation
- Hach
- Walchem
- Endress+Hauser
- Yokogawa
- Emerson (Rosemount)